PREFACE
Downloaded by 80.82.77.83 on January 6, 2018 | http://pubs.acs.org Publication Date: December 9, 1985 | doi: 10.1021/ba-1986-0211.pr001
ΊΗΕ SCIENCE OF MULTC IOMPONENT POLYMER MATERA ILS
arose because of the continued need to make and to understand improved engineering polymers and because of the reduced probability of discovering new, inexpensive, broad utility homopolymers. Through the developing science of mixing known polymers, advantageous property relationships can be found. Polymers may be mixed with many materials. They may be plasticized with small molecules, colored, reinforced with particulate or fibrous fillers, or cross-linked through a variety of mechanisms. This work emphasizes the results of recent research on the mixing of two or more polymers. Polymer mixtures have been called by many names. The term polymer blends is widely used not only to describe mechanical mixtures of two polymers, but also to provide a generic description of graft and block copolymers, AB-cross-linked polymers, and interpenetrating polymer networks. Another name for polymer mixtures is polymer alloys, a term which reminds us of the metallic counterparts of polymer mixtures. Incidentally, many metallic alloys, including steel, exhibit phase separation, an important aspect of most polymer mixtures. An older term not in wide use today is interpolymers. The title of this book, "Multicom ponent Polymer Materials", presents a new and broader way to name collectively all the methods to combine two or more polymers. Kato's discovery of osmium tetroxide staining in 1964 provided an important new tool for the study of certain polymer blends. With properly stained samples, electron microscopy revealed a wealth of morphological detail down to a level of about 100 A. For example, solution graft copolymers of polybutadiene and polystyrene could easily be distinguished from mechanical blends. The reasons for the former's greater impact strength became clearer in terms of the domain size and complexity of domain structure. The probable locus of grafting sites was identified, and the interrelationships among synthetic detail, morphology, and mechanical properties were established. However, polymer blend science of that day was largely qualitative and depended on interpreta tion of such information as modulus-temperature curves, stress-strain data, and impact resistance in the light of their morphologies. Starting with research in the early 1970s, polymer scientists learned that by choosing complementary polymer pairs that attracted one xi
Paul and Sperling; Multicomponent Polymer Materials Advances in Chemistry; American Chemical Society: Washington, DC, 1985.
Downloaded by 80.82.77.83 on January 6, 2018 | http://pubs.acs.org Publication Date: December 9, 1985 | doi: 10.1021/ba-1986-0211.pr001
another, rather than similar pairs that merely repelled one another to lesser degrees, miscible polymer pairs could be systematically identified. The resulting phase diagrams often show lower critical solution temperatures, and these results have led to a more sophisticated science for polymer blend thermodynamics. The editors wish to thank many people for their part in making this book possible. First are the many secretaries who typed each of the manuscripts, perhaps many times. Susan Robinson of the American Chemical Society did an outstanding job in handling the mechanics of refereeing and editing. We also wish to thank our respective universities for providing the many professional services that ease the path to the preparation of books. D . R. PAUL University of Texas—Austin L. H .
SPERLING
Lehigh University August 1985
xii Paul and Sperling; Multicomponent Polymer Materials Advances in Chemistry; American Chemical Society: Washington, DC, 1985.
