Polymer Science in Undergraduate Chemical Engineering and

In the Classroom

Polymer Science in Undergraduate Chemical Engineering and Industrial Chemistry Curricula: A Modular Approach Martina H. Stenzel* and Christopher Barner-Kowollik** Centre for Advanced Macromolecular Design, School of Chemical Sciences and Engineering, The University of New South Wales, Sydney, NSW 2052, Australia;*[email protected] **[email protected]

Polymer science has permeated the modern world with polymeric products finding application areas ranging from construction materials, drug design, computing hardware, and optoelectronics to healthcare as well as biomedical applications. A solid understanding of the principles of polymerization and the underpinning structure–property relationships governing the performance of polymeric materials alongside an overview of the important synthetic methods is a mandatory element in the eduction of well-rounded chemists and chemical engineers. The content requirements of the polymer science curricula for chemical engineers and chemists are dictated by the professional practice and can vary significantly for both disciplines. This university is in the unique position of offering a chemical engineering degree with a strong focus on process engineering alongside an industrial chemistry degree that is largely focused on chemistry as a science, while having some process engineering elements. The chemical engineering students also have the possibility of enrolling in a 5-year program of biomedical engineering that is identical to the 4-year chemical engineering course but includes an array of additional lectures relevant to the development of biomedical devices and procedures. The parallel education of chemical engineers and biomedical engineers and chemists in one school has led to the development of a finely structured and modern polymer science curriculum for both disciplines, implemented in a modular structure (refer to Figure 1 for an overview of the curriculum structure). Our curriculum especially takes into account that some areas of polymer science, most prominently the field of advanced polymer synthesis, are subject to a rapid development of novel procedures that are beginning to revolutionize the entire industry. Jefferson and Philips (1) have commented that many chemistry departments do not teach any courses

Figure 1. Schematic depiction of the polymer curriculum system.

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in polymer science or polymer chemistry, largely driven by the fear of having to rationalize and cut more traditional chemistry content as well as not being able to include recent advances in modern synthetic methods in their curricula. However, that this seemingly artificial separation of polymer science and chemistry (including its advanced methods) is not justifiable becomes evident when considering the increasing fusion of classical organic and inorganic chemistry with modern polymer science in areas such as living free radical polymerization methodologies, including atom transfer radical polymerization (ATRP) (2), reversible addition fragmentation chain transfer (RAFT) (3) polymerization as well as nitroxide mediated polymerization (NMP) (2). Indeed, Matyjaszewski and co-workers (4) have recently demonstrated that modern polymer synthesis methodologies can be implemented within the classical chemistry undergraduate curriculum with ease by providing two examples for undergraduate laboratory experiments at the nexus of organic chemistry and polymer synthesis. A survey of the literature indicates that while the need to implement polymer science content in the chemical engineering and chemistry curricula has long been identified as important (5, 6), there are no recent reports describing the implementation of a comprehensive and modern polymer curriculum at the nexus of advanced organic synthesis and polymer chemistry for neither the chemistry nor chemical engineering degrees. The last major review of this topic was carried out in the early 1980s and resulted in an American Chemical Society recommended syllabus (7) for introductory courses in polymer chemistry. Almost two decades later, in 2001, a survey of the available polymer education literature and the incorporation of polymer science in mainstream chemistry curricula by Bigger and co-workers (8) indicated that “the topic of polymers is given not only variable treatment […], but insufficient attention overall.” The authors concluded that “despite the commonplace of polymers in most modern societies, polymer education as an academic subject is widely acknowledged to have lagged behind other areas.” The present deficiencies in polymer science education have also been noted very recently, and, as Royappa states, “Despite the acknowledged importance of polymer science, very few universities and colleges offer even a single course in this subject” (9). It is the aim of the present contribution to demonstrate how a modular curriculum system of contemporary and cutting-edge polymer science for chemical engineering and chemistry degrees is implemented and what specific content is being addressed. At the same time we not only wish to comment on the technical details of our implementation, but also on our specific modes of course delivery that are multifacetted and range from classical lecture or tutorial style to interactive group work.

Vol. 83 No. 10 October 2006

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Journal of Chemical Education

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Polymer Science for Chemists

Course Content and Learning Context The industrial chemistry degree offered at our university essentially provides a classical chemistry education incorporating physical, organic, and inorganic elements at both a theoretical and synthetic level. However, the program is enriched by specific subjects that are traditionally associated with chemical engineering programs. The content of the degree is selected to give the industrial chemistry graduate the capacity to work in a synthetic industrial setting with the scope to also develop successful strategies for reaction scaleup and pilot plant design. The underpinning teaching philosophy of the industrial chemistry program is oriented towards student-centered and problem-based learning, providing the students with the capabilities to solve complex problems at the interface of classical chemistry and chemical engineering. The additional subjects the industrial chemistry students take include experimental design, mass and heat transfer as well as reaction engineering and reactor design alongside specific courses addressing industrial organic chemistry. Polymer science is introduced in year three of the program, after the students have developed a firm understanding of the concepts and key ideas of organic chemistry as well as kinetics and thermodynamics taught in the second year. The key guiding principles in the design of this polymer science sequence, which is taught over two courses, is to provide a close interplay between theoretical underpinnings, practical laboratory practice, and literature-based investigations. The principal sections of the two courses are polymer chemistry and polymer physics. Table 1 details the general content areas of both courses for the lectures and laboratory exercises. During the first course, the students are introduced to the fundamental concepts of polymer chemistry and polymer physics. The course begins with a general introduction to the history of polymer chemistry and the broad range of applications of polymers in a variety of fields. Special em-

phasis is given to the fact that biopolymers play an enormous role in the natural world with DNA and proteins essentially being condensation polymers. The course subsequently ventures into step polymerization chemistry (addition and condensation mechanism and their resulting polymers). Since the students at this stage have sound background knowledge in organic chemistry, it seems natural to start a course in polymer chemistry by discussing polymerization techniques that are related to basic organic chemistry. During the discussion of addition and condensation processes, particular emphasis is placed on the kinetics of the process and the evolution of the molecular weight (i.e., the average degree of polymerization) with monomer to polymer conversion as described by the Carothers equation (10). While at this stage the concept of “average molecular weight” and “molecular weight distribution” have not yet been formally introduced, we believe that an early familiarization with the kinetic behavior of step polymerizations aids significantly in its understanding. Strict definitions of the various molecular weight averages are formally introduced in the extensive section on free radical polymerization. The step polymerization segment also makes note of the fields of application of step polymers, which range from polycarbonates for compact disks to biodegradable scaffolds for tissue engineering applications. The course subsequently moves into the chemistry and fundamentals of chain polymerization techniques, focusing initially on cationic and anionic processes. Anionic polymerization is covered extensively as it serves an example to illustrate the key concept of “living” polymerization, which is covered in its all important free radical variety in the second course. Further, anionic polymerization serves as the platform to introduce the students to the concept of “macromolecular engineering”, which in its widest definition implies the construction of well-defined complex polymer architectures ranging from polymer star, combs, and spheres. In the section on cationic and anionic polymerization, the key reaction steps of chain polymerization processes (i.e., initiation, propaga-

Table 1. Structure and Content of Polymer Science I and Polymer Science II Course I

Week

Lecture a

Polymer Physics

Polymer Chemistry

Tutorial

1–2

Polycondensation/Polyaddition

•

3–4

Cationic/Anionic Polymerization

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5–6

Free Radical Polymerization

b

Laboratory

Morphology of Polymers

9–10 11–12 13–14

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Flow Properties

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Polymers in Solution

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Molecular Weight Analysis

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1–2

Free Radical Copolymerization

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Risk Assessment

3–4

Free Radical Copolymerization

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Polycondensation

5–6

Living Free Radical Polymerization

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Free Radical Polymerization

7–8 9–10

SEC and Viscosity

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DSC

•

11–12

•

13–14 a

The lectures are 2 hours per week.

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Literature

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7–8

II

a

• b

Tutorials are 1 hour per week.


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In the Classroom

tion, transfer, and termination) are thoroughly introduced and the resulting implications for the two processes, especially in contrast to step polymerizations, are discussed. The discussion also entails a section on monomer selection and structure–reactivity relationships. Finally, free radical polymerization (FRP) is introduced by discussing each reaction step in a separate unit, that is, moving from initiation, propagation, transfer, and finally to termination. The content includes the kinetics of each reaction step (including approaches to control the reactivity of, for example, free radical initiators via structural variation) alongside considerations of monomer and radical reactivity. The content also includes a section on process control including solution, suspension emulsion, and mini-emulsion FRP. Molecular weight averages and molecular weight distributions are introduced together with the key equations that allow for a prediction of the degree of polymerization and the engineering of polymeric material of predetermined molecular weights (i.e., the Mayo equation). At this stage of the course, the students are actively making the connection between the reaction kinetics course of their second year and the powerful predictive quality of polymer reaction kinetics with regard to the generated polymer chain distribution in the final product. The initial section of polymer chemistry is followed by a section on polymer physics. It is important that in the polymer physics section the connection to the earlier polymer chemistry content is highlighted and specific examples are drawn from the chemistry section. The content of the physics section aims at covering the fundamental aspects of the behavior of polymers in their solid state as well as in solution. The polymer physics starts with the introduction of essential definitions that are vital for an understanding of the macroscopic properties of polymers. Expressions such as constitution, configuration, and conformation of polymers are explained before continuing with the influence of structural constitution on the solid state and solution behavior. The students are subsequently introduced to polymer morphologies outlining the prerequisite for crystallinity and the forms of crystalline phases in a polymer. The discussion on morphology leads to the introduction of the thermal and mechanical behavior of polymers as well as the properties of copolymers. A focus hereby is the ability to estimate the morphology of a polymer including its glass-transition temperature from the chemical structure of a polymer. By the end of week 9 the students are able to approximate the possible thermal properties and morphologies of a polymer in the classroom just by optical and sensual examination. The importance of polymers in solution for processing, molecular weight determination, or in a product such as paint is highlighted in the following four weeks. The coverage of several models to determine the dimensions of polymers is followed by the introduction to simple polymer–solvent interaction via a Flory–Huggins model. The lecture is then concluded with an introduction to the most prominent molecular weight determination techniques (such as size exclusion chromatography, light scattering, and viscometry). In the second course, the thread of FRP is revisited and the topic is broadened to free radical copolymerizations. Various copolymerization models are discussed in both theory and relevance to the industrial practice. In addition, a range

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of industrially important block copolymers are discussed from styrene–butadiene synthetic rubbers to ethylene–vinyl acetate polymers for packaging applications. The lecture component then moves on to discuss in-depth the novel living free radical polymerization processes (LFRP) (i.e., NMP, ATRP, and RAFT process) with respect to their mechanism, kinetics, and, most importantly, macromolecular architectural design capabilities (macromolecular engineering) with respect to various monomers. The introduction of LFRP makes use of the definition for living polymerization introduced in the first course when anionic polymerization was discussed. The students are given a sense of the FRP revolution that has occurred over the last 10 years and that has, unfortunately, not yet made it to most undergraduate implementations of polymer chemistry. In parallel to the theoretical lecture and tutorial work, the students are engaged in laboratory experiments that aim to deepen the theoretical understanding. The content can consist of experiments covering the fundamental aspects of step and (living) FRP (including the well-designed undergraduate experiments of Matyjaszewski and co-workers; ref 4 ) as well as polymer characterization and polymer physics. In our specific implementation, we have included experiments on polycondensation and FRP and the subsequent characterization of the generated polymers via size exclusion chromatography (SEC) as well as differential scanning calorimetry (DSC). The choice of experiments is certainly dependent on the number of students, the available lab equipment, and the lab demonstrators. The choice of experiments should be tailored to the fundamentals learned during lecture. However, within that range there are a lot of suitable experiments available and appropriate polymer lab books can help with the choice (11). The latter part of the second course also contains a literature exercise in polymer physics. The key idea is to introduce the students to reading and writing of scientific publications. Being able to assimilate information from scientific publications is not only crucial in an industrial context but mandatory for any subsequent academic work (such as a master or doctoral project). With completion of the two polymer courses the students are now equipped with the fundamental knowledge to understand scientific publications on the latest research development in polymer chemistry or physics.

Teaching Practice The teaching philosophy course I and course II is based on the fact that learning is best facilitated by a troika of components: (i) Embedding the current lecture content in the context of the material that the students have covered in earlier courses. For an introductory course to polymer science for chemists, these are reaction kinetics and thermodynamics as well as organic chemistry. Constant cross referencing to the earlier learning contexts generates a coherent picture for the students and demonstrates the relevance of earlier courses. (ii) Interactive lecture components that avoid teachercentered learning as much as possible. We achieve this by dispersing the lecture activity with tutorial questions, which are handed out during each lecture. The classroom experience thus consists of a series of 20-minute information pieces, after which a tutorial questions is solved in groups of 3 to 4 students and the results are presented on the white board.1


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The tutorial sections also provide an opportunity for the lecturer to approach the students while they work on the questions and gather information of the degree of understanding they achieved. Ideally, the lecturer can subsequently address general misconceptions for the entire class and identify students struggling with the material and thus offer targeted help and advice. The learned material is, in parallel, also practiced in two written (and graded) assignments that each student solves independently. (iii) Hands-on laboratory work is an essential learning tool in gaining an in-depth understanding of the theoretical material covered in class. Equally, it is important that the chemistry students develop practical laboratory skills. Although not laboratory based, the ability to extract relevant data from a broad information base (such as scientific publications) can also be classed as practical skill and it is for this reason that our approach also includes a comprehensive literature exercise. Table 1 indicates that the course outline combines all of the above elements. The first course is strongly focused on interactive lectures with a tutorial sheet provided during each lecture. In the second course, the students experience a laboratory component in groups of 3 to 4 students. The laboratory class takes places once per week with a total of 10 laboratory weeks. Depending on the resources available and overall class size, it is also possible to carry out the laboratory component in slightly differing formats. The content of the laboratory segment is tailored such that it covers the basic principles of step and chain polymerization as well as addressing aspects of polymer characterization and polymer physics. Naturally, the selection of laboratory experiments is somewhat subjective and arguments for the inclusion or deletion of experiments can be constructed. However, the laboratory component must focus on the fundamentals and it would be unwise to engage at this stage in too specialized experiments.2 For each experiment, the students are required to write a detailed laboratory report that is graded. The laboratory component entails a quiz, discussion, and briefing before each experiments as well as a debriefing meeting, in which the submitted reports are discussed. Table 1 also indicates that in parallel to the laboratorybased experiments, the students are engaged in literature work. Typically, the students are given a research publication of a high-impact journal covering a topic dealing with the latest developments in polymer physics. The students are required to carry out a comprehensive literature search identifying three more recent publications dealing with the same subject. Subsequently the students are required to extract the key information of each publication and to combine them into one publication using their own (scientific) words. The purpose of this exercise is not only to foster the understanding of a topic area that is new and has not been discussed in the lecture but also to identify the important conclusions of a publication. In addition, the students are required to become familiar with search engines for scientific topics. The final report is formatted like a publication and is graded according to its scientific content, the ability to carry out a literature search, and the correct use of scientific terms. In effect, the academic grader is acting as if he or she was reviewing a research submission from a colleague.

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Polymer Science of Chemical Engineers

Course Content and Learning Context Traditionally, polymer chemistry is not taught in most chemical engineering curricula, especially not in those with a stronger emphasis on process engineering. This is puzzling, since chemical engineers have a high likelihood of coming into contact with the manufacture of polymeric materials during their professional lives. It is thus, at least in our view, mandatory that the option of enrolling in a basic polymer chemistry course is included in chemical engineering curricula. To address this gap, we have designed a fourth-year polymer chemistry–polymer science course for chemical engineers with a limited chemistry background, especially in synthetic organic chemistry. Thus, the course has to review the most important organic chemistry concepts and this is largely achieved in the context of the tutorials. The course contains content similar to the two courses designed for the chemistry students; however, the engineering course does not include a laboratory (Table 2). In addition, the depth of the content coverage is significantly different from the chemistry course: The main learning outcome for the chemical engineering student is a broad understanding of the underpinning principles, with a relatively small degree of highly detailed knowledge, while the outcome for the chemists is clearly focused on developing the students’ ability to solve detailed and specific synthetic and mechanistic polymerization problems. For example, both courses cover and discuss living FRP processes. While we would expect a chemist to be able to develop synthetic strategies to arrive at, for example, a 6-armed star-block copolymers via RAFT, ATRP, or NMP, the expectation from the chemical engineers would be to critically understand the basic chemistry of each process and illustrate the advantages and disadvantages of each technique in broad terms, that is, which monomers can be polymerized by each technique, what are the key reaction sequences that induce living behavior, what aspects of the techniques are important issues with respect to process control and design. Teaching Practice The chemical engineering students’ background knowledge and problem-solving strategy are significantly different from those of the industrial chemistry students. While the chemistry students’ degree is focused on understanding how chemical reactions proceed on a molecular level, the chemical engineers are focused on efficient process development. As a consequence, their degree is more practice-based and covers considerably less theory, making more use of empirical models. Typically, a chemistry student, when asked to comment on a chemical, for example, toluene, will draw the structure and map out its possible reaction pathways, while a chemical engineering student will give the properties of the chemical, for example, boiling point, viscosity, and so forth. Thus, the perspective of a chemical engineering student is fundamentally different from that of a chemistry student. It is the lecturer’s challenge in course design and delivery to bridge this gap. Therefore, even more than in the two polymer science courses offered for chemists, the tutorials are an


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integral and extremely important component of the engineering course, arguably more important than the lectures themselves. Within the tutorials, the covered material is placed in the context of the chemical engineering practice. Polymer Science for Chemical Engineers with Biomedical Specialization

Course Content and Learning Context A polymer science course was originally not part of the curriculum of the graduate degree in biomedical engineering. The focus of the degree was initially biased towards the stability of materials and their interaction with biological environments. However, a strong need for knowledge in material design to improve current biomaterials was identified. Biomaterial science nowadays is so far advanced that commercially available polymers are not sufficient to create new scaffolds for tissue engineering or scaffolds for drug delivery systems. The graduate degree of biomedical engineering is a fiveyear program that is based on traditional chemical engineering (the degree will also accept students from other engineering degrees, however, chemical engineers have always been the largest proportion of students). The students obtain a strong background in biology and medical science to form the nexus between these three disciplines. The polymer course is an elective for students in their final year and mainly recommended for students with a background in chemical engineering or materials engineering.

While the required chemistry knowledge for this course is rather basic, a certain fundamental knowledge in organic chemistry is prerequisite. However, some essential organic reactions will be repeated during the course. The course is designed to accommodate the needs of biomedical engineers with a strong focus on the correlation between polymer structure and the properties of polymers in solution and solid state. The course spans the whole area of polymer science giving an introduction not only to the synthesis of polymers but also to processing, testing of materials, and degradation (for a detailed content listing see Table 3). The focus of the course is to give the students a broad overview of all aspects of polymer science. This is necessary, because students in biomedical engineering typically deal with a range of challenges ranging from synthesis to properties and stability when designing a new biomaterial.

Teaching Practice Biomedical engineers, similar to chemical engineers, focus on the application of (empirical) theory. Material design using structure–property relationships is one of the major focal points in their polymer science education. There is, however, a strong emphasis on the importance of polymer synthesis and the influence of the synthetic pathways on the properties of the generated polymers. The course is structured according to the logical development of a material, starting with the synthesis and subsequently progressing to processing and degradation. The three-hour weekly lecture is underpinned by tutorial questions, which allow the students to

Table 2. Structure and Content of the Elective Course Polymer Science for Chemical Engineers Week

Student Activitya

Lecture Content

1

Products made from polymers

Tut. I: Review of organic chemisty

2

Addition and condensation polymerization

Tut. II: Step Polymerization

3

Types of initiators, industrially relevant initiators, initiation mechanisms

Tut. III: Initiation

4

Trends and guidelines of selecting monomers on the basis of their chemical structure, rate of propagation

Tut. IV: Propagation

5

Termination reactions in free radical polymerization, modes of termination, diffusion control

Tut. V: Termination Lab visit: Gel effect

6

Deriving the rate of polymerization equation, applicability and limits of this equation

Tut. VI: Rates of polymerization

7

Characterization of polymers: the molecular weight distribution, molecular weight averages

Tut. VII: Molecular weight averages

8

SEC and mass spectrometry, understanding and interpreting molecular weight distributions

Lab visit: SEC and mass spectrometry

9

Controlling the molecular weight of polymers generated via FRP: the transfer reaction

Tut. VIII: The Mayo equation

Copolymerization models, reactivity in copolymerization, reactivity ratios and the copolymerization equation

Tut. IX: Copolymerization models

10 11

Introduction to LFRP: principles and concepts

Brainstorming: Towards LFRP

12

NMP

Tut. X: NMP

13

Principles of the ATRP process

Tut. XI: ATRP

14

Introduction to the RAFT process, basic concepts

Tut. XII: RAFT

Novel macromolecular architectures via living FRP

Review of course material

13–14 a

In weeks 4, 8, and 13 the students are required to hand in a comprehensive written assignment on the topics covered in the previous weeks. The assignments are written answers or calculations to 4–6 detailed questions or problems.

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apply the theory immediately, using current examples or case studies. While the understanding of fundamentals is certainly an important part of the lecture, the application of the theory has a high relevance. Since these students are in their fifth year and already involved in their honors or masters research project, the emphasis of the tutorials is considerably shifted from theory to application, especially when compared with the two courses for the chemistry students. In the case studies, the students have to develop possible solutions, which are subject to discussion. The tutorial is not necessarily tailored towards the application of factual knowledge but rather geared to develop a sense for materials and their properties as well as their best possible synthesis. A lab part enhances the students’ ability to observe property changes and relate this to structural changes. Advanced Polymer Science

Course Content and Learning Context The advanced polymer science module is a fourth-year subject that can be taken by students from all of the above

degree streams. Thus, this course brings together students from a variety of backgrounds (i.e., industrial chemistry, chemical engineering, and biomedical engineering), while at the same time having to address the specific content requirements of each degree. Upon first inspection it may seem that such a requirement will be difficult to meet. However, we have implemented the advanced polymer science course also in a modular fashion, so that the needs and interests of each group of students are met. The course consists of four separate units that are taught by a different lecturer. The lecturer for each specific component is an expert in the field being covered in the course and can thus best design the lecture material and tutorial session at the nexus of research and teaching. The four segments of the course are chosen so that they represent a diversity of areas congruent with the nature of the student body, that is, LFRP in two segments covering the RAFT process and ATRP, one segment on polymers in drug-delivery applications and one segment on specific industrial polymerization methodologies including high-pressure polyethylene synthesis and Ziegler–Natta polymerization. The structure of the course is depicted in Table 4.

Table 3. Structure and Content of the Elective Course, Polymer Science for Biomedical Engineers Week Lecture Content

Student Activitya

1

Introduction to polymers: history and definitions; Step polymerization I: from organic chemistry to polymers

Tut. I: Calculation of number and weight average molecular weight; synthesis of different step-growth polymers

2

Step polymerization II: examples of linear and network polymers, kinetics of polymerization; Radical polymerization I: mechanism

Tut. II: Calculation of theoretical molecular weight from conversion for ester synthesis; mechanism of radical polymerization of acrylonitrile

3

Radical polymerization II: kinetics, copolymerization, chain transfer

Tut. III: Determination of conversion and molecular weight using rate constants

4

Polymers in solution: dimension of polymers in solution and molecular weight determination

Tut. IV: Dimension of polymers

5

Polymer lab: synthesis and analysis of hydrogels, hydrolysis of poly(vinyl acetate) and cross-linking

–––––

6

Biopolymers I: DNA

Tut. V: Complementary DNA strands

7

Biopolymers II: proteins

Tut. VI: Collagene I mRNA translation

8

Biopolymers I: polysaccharides

–––––

9

Polymer lab: isolation and characterization of DNA

10

Polymers in the solid state I: crystalline and amorphous morphologies

Tut. VII: Relationship between polymer structure, processing of polymer and crystallinity

11

Polymers in the solid state II: thermal properties of polymers and phase behavior of copolymers

Tut. VIII: Prediction of glass-transition temperatures; DSC of amorphous and crystalline polymers; phase separation of block copolymers

12

Polymer processing: thermal and solvent processing (extrusion, molding)

Tut. IX: Critical evaluation of rheology, thermodynamics, and processing

13

Polymer testing: bulk, surface, biological

Tut. X: Evaluation of long-term biostability of Elast-Eon 2 using different testing methods

14

Polymer degradation: chemical and physical degradation

Tut. XI: Case studies on the degradation of biomaterials in vivo

a

The course includes three short quizzes in weeks 5, 10, and 13.

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Teaching Practice The delivery mode of the advanced polymer science course is substantially different from that applied in the other polymer courses in our polymer curriculum. This final-year course departs from the classical lecture–tutorial–exam format of most courses and introduces a more innovative delivery mode that takes the maturity and knowledge of the student explicitly into account. In each of the four segments of the 14-week course, the students are presented with three, 2-hour interactive lectures. Interactive in this context means that the students are involved in a dialogue with the lecturer while the content is developed. In the first lecture, this dialogue can take the form of questions about material covered in earlier modules; it will later on move to concrete involvement of the students in the development of key concepts. For example, in the segment on LFRP via the RAFT process, the fact that many RAFT-mediated polymerizations are rate-retarded is introduced. The students are then asked (in a short 10-minute brainstorming session) to put forward mechanistic scenarios that could induce such effects. The results of this exercise are collated on the board and are then further developed by comparing the student’s suggestions with actual research findings. A similar interactive structure is adopted for various topics in each segment. Before the start of the course, the students are randomly allocated into groups (typically 4 students to a group, with approximately 6 groups in the entire course). After the completion of each lecture segment, each group is given a recent scientific research publication in the field of the lecture. The group is asked to analyze the content of the publication and take the role of a scientific referee in constructively criticizing the methodology and scientific merit. After completion of the analysis process, which proceeds within a week with little to no lecturer interference, the students are asked to present their findings to the entire class in a 30minute presentation. In this presentation, the students are required to (i) detail the content of the study in a fashion so that each class member achieves a clear understanding of the subject matter and (ii) constructively criticize the scientific approach and content by highlighting weaknesses as well as (iii) clearly indicate in which way they would further the scientific research. The presentation is to made in such a way that each group member contributes equally to the presentation effort. The quality of the presentation (of the entire group) is graded by peer and lecturer assessment on an equal weighting (i.e., peer:lecturer assessment is 50:50). The over-

all grade for the course is the equal weighting of the four presentations. Experience has shown that this format works well in a final-year context, with almost all students engaging with the subject matter. Student Response In all of the courses, the teaching modes are continuously evaluated via formal student feedback with respect to the teaching performance of each lecturer involved as well as the general setup of the entire course and its effectiveness in engaging the students and creating an inspiring learning environment. While the ratings for the individual lecturers vary somewhat (as would be expected given the different personalities involved), the classes are consistently assessed as varied, engaging, and exciting by the students. Typically, the students are highly appreciative of the interactive lecture style (in all of the courses) where tutorial questions are followed by short lecture intervals, such a teaching mode is clearly preferred over the more traditional long lecture block–tutorial block style still operative in many departments. Symptomatically, many students comment on the experience with expressions of amazement, indicating that they had “no idea” what polymer science had to offer and how relevant it was for their professional development. In the laboratory exercises, we found it crucial (and also made improvement in this respect) to have highly qualified and motivated postgraduate demonstrators with the students in the lab. It was also positively noted that the lectures contained frequent cross references to the respective laboratory experiments. The thirdyear students particularly enjoy the polymer physics literature research exercise because it lets them venture into unknown territory and allows them to apply the lecture material in a research-type setting. Particularly positive feedback is also received for activities that depart from conventional university routine such as the assessment mode via the group presentations in advanced polymer science on the basis of the students’ evaluation of a cutting-edge research article. Partly driven by the non-conventional assessment type but mostly driven by the analysis of a relevant piece of work, as opposed to some arbitrarily created example, the students actually feel themselves to be equal partners in the scientific discovery and discussion process. On some occasions, a student presented the work from such an unexpected angle that it actually led the involved academics to explore new directions in their own research. The advanced polymer science assessment exercise is, at least in our view, an excellent example of how assess-

Table 4. Structure and Content of the Elective Course Advanced Polymer Science Week

Lecture Content

Student Activity

1–2

Mechanism and kinetics of the RAFT process

------

3–4

Complex macromolecular architectures via RAFT

Week 4: presentation

5–6

ATRP: mechanism and applications

------

7–8 9–10

ATRP: mechanism and applications


Polymers for drug delivery

------

11–12

Polymers for tissue engineering


13–14

Ziegler–Natta polymerization


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ment drives student behavior and can be employed to the advantage of both student and teacher. It is also interesting to briefly inspect the feedback on the course structure of the more engineering-focused courses. In these courses, the fundamental premise of engaging the students via tutorial type discussions is even more important because the students do not have a strong chemistry background. The small class sizes that we encounter in these courses offer the possibility of responding to almost every student individually and placing the concepts into each student’s own degree context. Thus, tutorial-type classroom situations, which include group work by the students with the subsequent presentation of the results on the board, receive positive feedback from the students. The comments typically include statements such as “I had no idea that polymer chemistry is so interesting and relevant for my degree; I wish I had known this earlier.” We believe such comments are symptomatic and serve to reinforce our and other’s claim (8) that polymer science is in its entirely underrepresented in undergraduate curricula and cross referencing to polymer science issues only occurs on a minimal level in related courses. Relevant Textbooks and Literature The available sources of information for the preparation of the lecturer as well as the students in the general field of polymer science are manifold. The lecturer and the students can choose from a range of textbooks, research publications, educational publications as well as the Internet. However, not all sources have the same merits and the lecturer should discuss with the students the problems involved with the Internet as literature source. Some students tend to use Internet information as a primary source without any further critical evaluation of its content. We recommend textbooks and educational publications for the preparation of introductory polymer courses. However, even the best textbook can never replace the lecturer’s own teaching rationale and a thorough preparation. Advanced courses, in contrast, usually require a thorough literature research of recent scientific publications since these topics have rarely been covered by textbooks. The educational polymer-related literature is certainly an excellent basis for lecture preparation since the material is already pre-structured in a way that is suitable for teaching. A review of the educational literature in polymer science has been published recently with the literature being classified into five areas: synthesis, properties, characterization, reactions, and miscellaneous (8). Upon implementation of the current polymer science course, we have extensively debated whether to provide the students with printed and detailed lecture notes. There exist valid arguments for and against such provision in terms of the student’s learning behavior. However, within the present set of courses where we fuse traditional polymer science with advanced polymer synthesis, it is challenging to recommend textbooks that cover the novel LFRP methodologies in great depths. It is for this reason that our lecture notes are comprehensive and can serve as the stand-alone text for the courses. It has been repeatedly pointed out by our students that a systematic and logical order including numbered headings and subheadings of the topics facilitate understanding 1528


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and hence the learning process. Thus, at least in our implementation, the students are provided with well-structured printed lecture notes for each of the courses; however, a comprehensive literature list is also provided. Naturally, the classical themes of polycondensation, ionic, and FRP are covered in the standard textbooks, but, already for advanced FRP coverage especially in the field of polyreaction kinetics and mechanism, most textbooks are not up-to-date on the latest technologies. In the following, we briefly outline a range suitable textbooks for each course. Our list is not comprehensive and somewhat subjective, but constitutes good entry points for further reading and exploration.

Polymer Science for Undergraduates The classic text, which is still highly relevant despite its publication in 1953, is Flory’s polymer chemistry textbook (12). While a range of aspects in polymer kinetics has been further developed since it has been published, the book is still an important source for theoretical and statistical calculations on polymers. Campbell’s text (13) is certainly worth mentioning since it gives a comprehensive introduction to polymer science and has been recommended elsewhere (14). However, the book does not cover many aspects of polymer chemistry and physics and is therefore insufficient as a standalone text for an introductory course in polymer science. We would like to recommend a few textbooks that cover a large proportion of the content of the lectures and provide the students with detailed information as a supplement to the lecture notes. Additionally, these books are concisely written, making even complicated topics easy to understand. Further, they are relatively affordable. The first text is Billmeyer’s book (15) of polymer science, which represents an introduction to all areas of polymer science without losing itself in detail. It is divided into six chapters covering an introduction, synthesis, characterization, structure and properties, properties of commercial polymers, and polymer processing. The book has an extensive bibliography that cites the original research publications. The book is therefore a good starting point for further literature research. Each chapter concludes with a limited selection of study and reflection questions, which could, however, be more substantial. Second, a worthwhile textbook similar in style to Billmeyer’s text is from Coleman and Painter (16). Allcock, Lampe, and Mark (17) wrote one of the best textbooks to span the entire area of polymer science. Its structure is similar to Billmeyer’s book, comprising five chapters: synthesis and reactions of polymers; thermodynamic and kinetics of polymerization processes; physical characterization of polymers; fabrication and testing of polymers; and molecular structure, properties, and selected fields of application. The book includes some contemporary topics in polymer science such as biopolymers or new polymerization techniques. The last chapter even connects fundamental polymer science to the latest research, such as the application of polymers as biomaterials. While a list of suggested further reading is added to each chapter, the book does not include references to the original research publications. Some excellent textbooks focusing only on certain aspects of polymer science are also available. The classical text for polymer synthesis is certainly the one of Odian (18),


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In the Classroom

which, in its latest edition, also covers LFRP processes in a limited manner. The particular strength of the text is its rigorous treatment of polyreaction kinetics and the fundamental principles of the polymerization processes. In addition, it features a wide range of tutorial problems. Its weakness is on polymer properties and polymer physics, but as its title suggests, a treatment of such areas with rigor is not its intention. A book recommended for polymer physics was written by Sperling (19). This book focuses on physical chemistry and properties of polymers dealing with traditional topics such as polymers in solution and in solid state. But also more recent advancements in research have been added such as topics on surface analysis. It has been highlighted in a book review that the referencing of primary literature is exceptional (20).

Advanced Polymer Science The nature of this course makes it extremely difficult to recommend one definite text. This structural difficulty is corroborated by the relatively specialized topics covered, which tend to be written for the active research community (rather than for an undergraduate student audience) and often carry a prohibitive price tag. For an in-depth coverage of the novel LFRP processes, the Handbook of Radical Polymerization edited by Matyjaszewski and Davis is certainly one of the texts and includes contributions from the most respected and wellknown experts in the field (21). The text of Elias (22) is a well-written advanced textbook that covers all topics related to polymer science in great depth. The book is not suitable for an introductory course in polymer science since it assumes a high degree of chemical knowledge, but an advanced polymer course will certainly profit from its use. While the above two texts are excellently suited to supplement the aspects of the course relating to polymerization processes (including Ziegler–Natta polymerization partly covered by Elias), we would further like to recommend one text relating to the use of polymers (and other materials) in biomedical applications as well as one additional text for Ziegler–Natta polymerization. The book edited by Ratner, Hoffman, Schoen, and Lemons covers large areas of the field including biological aspects, medical applications, markets, regulations as well as ethical issues involved in biomaterial science (23). Scheirs and Kaminsky have provided a truly comprehensive coverage of metallocene-based polyolefins including their preparation, properties, and technological applications (24). As with any course conducted along the cutting edge of contemporary research, we encourage the strong incorporation of recent research publications into the lecture content. Naturally, a list of potential publications for the topics covered in our implementation would exceed the scope of the present contribution. Clearly, the content of this course as presented in the present contribution could easily be modified and many readers will miss important topics including emulsion polymerization processes, ring-opening polymerization, and electrically conducting polymers, to name but a few. The choice of content in our implementation was largely driven by the available research strength at our university and other faculties may place the accents differently. We believe that such a targeted selection of topics is permissible for an elective subject. www.JCE.DivCHED.org

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Conclusions In the present contribution we have demonstrated that a modern and engaging polymer science curriculum can be constructed for students from various degrees by providing a fusion of traditional elements of polymer science and contemporary polymer science at the nexus of organic and inorganic chemistry embedded in a lively and diverse teaching practice. Student engagement and interest is maximized by varied activities in the course and, where applicable, unconventional assessment practices. There is little doubt that polymer science needs to be an integral element of every contemporary chemistry and chemical engineering degree and the present sample implementation is an attempt to close this gap in the chemistry and chemical engineering curriculum development. Acknowledgments The authors would like to thank the School of Chemical Sciences and Engineering at the University of New South Wales for providing an environment where novel course ideas and, even radical, re-implementations can not only be carried out, but are actively supported. The authors would also like to thank Peter Looker from the UNSW Teaching and Learning Unit for his constructive advice. Notes 1. Such a learning environment can best be achieved in groups no larger than 30 students, which is frequently the case in the industrial chemistry degree at our school. We realize that such low student兾staff ratios can not always be achieved. In cases where the student number exceeds approximately 30, it may be necessary to revert to a more traditional lecture style, with a larger tutorial section at the end of a large lecture block. In addition, it may be necessary to facilitate the tutorials with two academics or a postgraduate tutor. 2. Living free radial polymerization is considered as fundamental in our implementation.

Literature Cited 1. Jefferson, A.; Philips, D. N. J. Chem. Educ. 1999, 76, 232– 235. 2. (a) Matyjaszewski, K. Controlled兾Living Radical Polymerization–Progress. In ATRP, NMP and RAFT; American Chemical Society: Washington, DC, 2000; Vol. 768. (b) Hawker, C. J.; Bosman, A. W.; Harth, E. Chem. Rev. 2001, 101, 3661. (c) Hawker, Craig J. Angew. Chem., Int. Ed. Engl. 1995, 34, 1456. 3. (a) Mayadunne, R. T. A.; Rizzardo, E.; Chiefari, J.; Chong, Y. K.; Moad, G.; Thang, S. H. Macromolecules 1999, 32, 6977. (b) Barner–Kowollik, C.; Davis, T. P.; Heuts, J. P. A.; Stenzel, M. H.; Vana, P.; Whittaker, M. J. J. Polym. Sci. Polym. Chem. 2002, 41, 365. 4. Beers, K. L.; Woodworth, B.; Matyjaszewski, K. J. Chem. Educ. 2001, 78, 544–547. Matyjaszewski, K.; Beers, K. L.; Woodworth, B.; Metzner, Z. J. Chem. Educ. 2001, 78, 547– 550. 5. Wagener, K.; Ford, W. T. ChemTech 1984, 14, 721.


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In the Classroom 6. Marvel, C. S. ChemTech 1986, 16, 136–137. 7. Seymour, R. B. J. Chem. Educ. 1982, 59, 652–653. 8. Hodgson, S. C.; Bigger, S. W.; Billingham, N. C. J. Chem. Educ. 2001, 78, 555–556. 9. Royappa, A. Timothy. Initiating and Developing Experiments for an Undergraduate Course in the Fundamentals of Polymer Science. Abstracts of Papers, 224th ACS National Meeting, Boston, MA, August 18–22, 2002. 10. Carothers, W. H. J. Am. Chem. Soc. 1929, 51, 2548–2559. 11. Polymer Synthesis: Theory and Practice, Braun, D., Cherdron, H., Ritter, H., Eds.; Springer: Berlin, 2001. 12. Flory, P. J. Principles of Polymer Chemistry; Cornell University Press: Ithaca, NY. 1953. 13. Campbell, I. M. Introduction to Synthetic Polymers; Oxford University Press: New York, 1994. 14. Waldow, D. J. Chem. Educ. 2002, 79, 561. 15. Billmeyer, F. W. Textbook of Polymer Science; Wiley– Interscience: New York, 1984. 16. Coleman, M. M.; Painter, P. C. Fundamentals of Polymer Science; CRC Press: London. 1984.

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17. Allcock, H. R.; Lampe, F. W.; Mark, J. E. Contemporary Polymer Chemistry; Person Education Inc: Upper Saddle River, NJ, 2003. 18. Odain, G. Principles of Polymerization; Wiley–Interscience: New York, 2004. 19. Sperling, L. H. Introduction to Physical Polymer Science; WileyInterscience: New York, 2006. 20. Allin, S. B. J. Chem. Educ. 2001, 78, 1469. 21. Handbook of Radical Polymerization; Matyjaszewksi, K., Davis, T. P., Eds.; Wiley and Sons: New York, 2002. 22. Elias, H. G. Chemical Structures and Syntheses; Wiley–VCH: Weinheim, Germany, 2005; Vol. 1; Volumes 2 to 4 are currently in the progress of translation from German to English and will appear in press in due time. 23. Biomaterials Science: An Introduction to Materials in Medicine, 2nd ed.; Ratner, B., Hoffman, A., Schoen, F., Lemons, J., Eds.; Elsevier: London, 2004. 24. Metallocene–Based Polyolefins: Preparation, Properties and Technology; Scheirs, J., Kaminsky, W., Eds.; John Wiley and Sons: New York, 2000.


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