Sub-100 nm Cocontinuous Structures Fabricated in Immiscible

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Sub-100nm Co-continuous Structures Fabricated in Immiscible Commodity Polymer Blend with Extremely Low Volume/viscosity Ratio Fei Li, Xuewen Zhao, Hengti Wang, Qin Chen, Shuhua Wang, Zhenhua Chen, Xiaoyong Zhou, Wenchun Fan, Yongjin Li, and Jichun You ACS Appl. Polym. Mater., Just Accepted Manuscript • DOI: 10.1021/acsapm.8b00174 • Publication Date (Web): 18 Jan 2019 Downloaded from http://pubs.acs.org on January 20, 2019

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Sub-100nm Co-continuous Structures Fabricated in Immiscible Commodity Polymer Blend with Extremely Low Volume/viscosity Ratio Fei Li 1, Xuewen Zhao 1, Hengti Wang 1, Qin Chen 1, Shuhua Wang 2, Zhenhua Chen 2, Xiaoyong Zhou 2, Wenchun Fan 3, Yongjin Li *1, Jichun You*1 1. College of Material, Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou 311121, People’s Republic of China 2. Zhejiang Juhua Technology Center co.,ltd. 324004, Quzhou, People’s Republic of China 3. Zhejiang Juhua Research Institute of Newmaterials co. ltd. No. 258, Juxian Str., Hanghzou, 311321, People’s Republic of China.

ABSTRACT

Sub-100nm co-continuous structures have been prepared successfully in PVDF/PLLA blend with extremely low volume/viscosity ratio by melting blending. The reactive compatibilizer with PMMA side chains and random epoxide groups plays important roles in the formation and the size decrease of these structures. On one hand, PMMA side chains exhibit excellent entanglement with PVDF; on the other hand, the epoxide groups can react with carboxyl group of PLLA. The resultant comb-like compatibilizer exhibits greater capacity to maintain the stress balance on two sides. The repulsion state of the binary brushes enlarges the interface curvature radius, dominating the formation of co-continuous structures.

Keywords: Co-continuous structures; Compatibilization; PVDF; PLLA; Blend; *corresponding author: [email protected] or [email protected]

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Co-continuous structures in nanometers have been paid much attention in the past decades 1,2. Phase separation in immiscible polymer blend can serve as a template for the fabrication of them 3,4. In this strategy, however, there are two open problems. For one thing, the co-continuous composition/temperature window is very narrow in phase diagram. The approximate volume/viscosity ratios of two components are required to develop co-continuous structures, which can be expressed as equation (1) 5,6.

𝜙1

𝜙2

(1)

( 𝜂1 )/( 𝜂2 ) ≈ 1

Where 𝜙, η, the subscript of 1 and 2 represent volume, viscosity, phase 1 and phase 2 respectively. The fabrication of co-continuous structures from melting blending with extremely low (or high) volume/viscosity ratio seems very difficult or just impossible because the phase with lower volume and higher viscosity tends to form island phase and vice versa; for another thing, the characteristic sizes of phase-separated structures in blend systems locate mainly at microns

7,8.

Therefore, copolymers have been

employed to compatibilize the blend systems and decrease the characteristic sizes 9. For instance, Luo et al. utilized premade block copolymer composed by polystyrene (PS) and Poly(methyl methacrylate) (PMMA) as a compatibilizer in PS/PMMA blends

10,11.

Compatibilization of polymer blend by copolymer can reduce the size of

co-continuous structures to sub-micron at most

12.

The fabrication of sub-100nm

co-continuous structures from immiscible polymer blend with extremely low volume/viscosity ratio remains as one of the greatest challenge in this field. To obtain this structure, the precise localization of the compatibilizer at interface dominated by the balanced stress on two sides is necessary to reduce the interface tension and structure size. For this purpose, our attention has been paid to reactive blending, in which the compatibilizer forms in-situ at the immiscible interface. It exhibits higher compatibilization efficiency relative to premade copolymer and therefore has been regarded as a promising solution for the reduction of phase-separated structure size

13.

Meanwhile, it is the interface curvature radius that

dominates the formation of co-continuous structures14. It would be helpful to adopt 2

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the comb-like compatibilizers with enhanced ability to improve the interface curvature radius relative to the linear counterparts 15, 16. Scheme 1, the sea-island structures in PVDF/PLLA (A) and bigger (B) and smaller (C) co-continuous structure forms with the help of RCC and shear effect; (D) and (E) are the zoom-in area in the indicated part.

In this work, therefore, the reactive comb-like compatibilizer (RCC, FTIR and GPC are shown in Figure S1 and S2) with long polymethyl methacrylate (PMMA) side chains and epoxide groups randomly distributed along the PMMA backbone, has been employed to compatibilize commodity blends system by taking poly(vinylidene fluoride)/poly(L-lactic acid) (PVDF/PLLA) as an example (Scheme 1). Based on the excellent entanglement of PVDF/PMMA (resulted from the thermodynamical miscibility of them) 17 and the reaction between the epoxide groups (in RCC) and the terminal carboxyl group (of PLLA), the obtained comb-like molecules with double brushes are expected to play following roles in compatibilizing PVDF/PLLA blend system under well-controlled conditions. Firstly, it would be an effective strategy to balance the stress on two sides along the interface, resulting in the precise localization of comb compatibilizers at the interface, the decreased interface tension and lower magnitude of characteristic size of phase-separated structures (shown in Scheme 1A to 1C); secondly, the balanced stress on two sides and the existence of PMMA backbones lead to the organization of them along the interface (Scheme 1D); finally, the poor miscibility between PVDF (PMMA) and PLLA contributes to the repulsion state of the binary brushes (Scheme 1E). Both the PMMA backbone along interface 3

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and the repulsion effect of side/grafted chains are benefit to the forced improvement of interface curvature radius. Based on the smaller structure size and higher curvature radius, the sub-100nm co-continuous structures can be prepared in PVDF/PLLA with extremely low volume/viscosity ratio. To the best of our knowledge, this is the first time to prepare co-continuous structures in commodity polymer blend based on the combination of physical entanglement and chemical reaction.

Figure 1, (A and B) TEM images of PVDF/PLLA/RC (30/70/20%), (C and D) SEM images of porous PVDF membranes upon removing PLLA by acid hydrolyzing.

First of all, we calculated the volume/viscosity ratio (≈0.03) in PVDF/PLLA according to the rheology data shown in Figure S3 (based on the viscosity at lower frequency, 5900 Pa*s and 360 Pa*s for PVDF and PLLA respectively). It is very difficult to obtain co-continuous structures in this system according to the criterion shown in equation (1). To validate the phase-separated structures, thin slices of samples were microtomed in the blend specimen and examined by transmission electron microscope (TEM) (Figure 1A-1B). The TEM image of the sample without RCC has also been provided as reference (Figure S4). The white and black phases are 4

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PLLA and PVDF respectively since the latter is easily stained by the RuO4. The structures in TEM images (Figure 1A and 1B) are similar with the co-continuous structures reported in literatures 7, 10, 11. The characteristic size of this structure is less than 100nm. To validate the composition distribution in this blend, our specimens were immersed in 20% nitric acid solution at 90 oC for various periods to remove both the grafted and free PLLA in blend. The acid hydrolysis efficiency, defined as the ratio of weight loss during this process and the initial weight of PLLA, is under the control of the immersing time (Figure S5). It is facile to remove PLLA completely upon the treatment for 3 days, which has been confirmed by the weight calculation and the disappearance of melting peak of PLLA in DSC curves (Figure S6). The complete removal of PLLA indicates that it is continuous since it is impossible to do this when PLLA acts as islands. Meanwhile, the porous PVDF membranes are self-supporting (shown in Figure S7), indicating the continuous state of PVDF phase. According to the discussion above, the co-continuous state can be confirmed. It serves as the base for not only the successful removal of one component (PLLA) and the consequent interpenetrated pores, but also the self-supporting porous target (PVDF) membranes18,19. The SEM images of porous PVDF membranes are displayed in Figure 1C and 1D, in which the co-continuous structures including interpenetrated nanopores and PVDF are obvious. In the SEM images, the average pore size is less than 100nm. Mercury injection test was used to determine the pore size and its distribution of the porous PVDF membranes (shown in Figure S8). It is found that the average pore size locates at 50 nm, ranging from 20 to 100nm. Comparing with the characteristic size of the co-continuous structures, the pore size shows lower magnitude, which can be ascribed to the shrinkage during drying. Furthermore, the sub-100nm co-continuous structure exhibits good thermal stability upon annealing (shown in Figure S9).

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Figure 2, (A) photos of PVDF/PLLA with (right) and without (left) RCC; the mechanical properties (B) DSC thermograms of the first heating process of PVDF/PLLA blends. (C) (a) PVDF, (b) PLLA, (c) PVDF/PLLA/RCC (30/70/0%), (d) PVDF/PLLA/RCC (30/70/5%), (e) PVDF/PLLA/RCC (30/70/20%); SEM images of (D) PVDF/PLLA/RCC (30/70/0%), (E) PVDF/PLLA/RCC (30/70/5%) and (F) PVDF/PLLA/RCC (30/70/20%).

To assess the compatibilizer dependence of the compatibility between PVDF/PLLA, several methods have been employed. In blend system, the optical and mechanical properties depend crucially on the phase-separated structure size

20.

As shown in

Figure 2A, the specimen of PVDF/PLLA/RCC=30/70/20 exhibits much lower haze (Table S1) relative to the reference (PVDF/PLLA=30/70). Figure 2B shows the tensile curves of PVDF/PLLA/compatibilizer blend, in which the yielding stresses are close in all specimens. The elongation at break of PVDF/PLLA is roughly 68.9%. This value increases to 334.6% upon adding 20wt % compatibilizer (Table S2). The improved mechanical and optical properties should be attributed to the enhanced compatibility and resultant smaller phase-separated structures in PVDF/PLLA blend. In DSC results (Figure 2C), the addition of compatibilizer produces remarkable effect on the melting behaviors of PVDF and PLLA, suggesting the different crystallization behaviors during cooling process. The decreases of the melting temperatures (both component) and the crystallinity suggest that the blend exhibits better compatibility due to the existence of compatibilizer 21, which can be interpreted as the miscibility of the PMMA side chains in the compatibilizer with PVDF and the confined crystallization of PVDF resulted from the smaller domain size (Figure S10 and Table 6

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S3). The morphologies of PVDF/PLLA with various compatibilizer contents were investigated by scan electron microscope (SEM). To identify the composition distribution, chloroform has been used as the selective solvent to etch PLLA on the fracture of our specimens. As illustrated in Figure S11, SEM images before and after etching indicate that the matrix and island phase are PLLA and PVDF respectively. In Figure 2D, PVDF domains with the average size of 2.8 ± 0.9μm disperse in PLLA matrix. The higher domain size and polydispersity are typical morphologies of blend system with poor compatibility22,23. When compatibilizer is added in the blend system, our attention should be paid to following issues. Firstly, the characteristic sizes of phase-separated structures decrease to 0.35 and 0.10μm with the compatibilizer content of 5wt % and 20wt % respectively (Figure 2E, 2F and Figure S12); secondly, this size becomes more and more uniform with increasing the compatibilizer content, corresponding to the smaller error bar in Figure S12; finally, the PVDF islands tend to connect with each other, producing co-continuous structures. The phase conversion from island-sea to co-continuous structures is obvious in Figure 2F. Both the decrease of PVDF domain size and the continuity increase of the phase-separated structures agree well with the better mechanical and optical performances (Figure 2B and 2A) and the enhanced compatibility (Figure 2C, 2D to 2F) between PVDF and PLLA.

Figure 3, SEM images of PVDF/PLLA (A), PVDF/PLLA/RCC20% upon shear for 2min@20rpm (B), 2min@20rpm & 1min@50rpm (C), 2min@20rpm & 3min@50rpm (D), 2min@20rpm & 5min@50rpm (E), 2min@20rpm & 10min@50rpm (F). The red circle in (B) represents the 7

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breakup of long PVDF fibers which is the reason for co-continuous structures.

There are two different reported mechanisms for the formation of co-continuous structures

24,25.

In the first one, the investigators own it to the coalescence of

preformed particles25, 26. The second one assumes that co-continuous structures start from long fibers or sheets, which is followed by the breakup of them into networks24, 27-29.

To validate the structure formation mechanism in our system, we tracked the

structure evolution as a function of mixing time. There are long PVDF fibers when the blend has been premixed at 20rpm for 2min (Figure 3B). The breakup of these fibers is obvious, which has been highlighted by red circle. As a result, the co-continuous structures can be obtained in Figure 3C. Upon further mixing, the co-continuous state remains stable while the characteristic size drops from ~750nm (Figure 3C) to sub-100nm (Figure 3F). The size of them has been measured based on the software of Nano Measurer, which is shown in Figure S13. The size evolution (Figure S14) indicates a rapid compatibilization process. SEM results shown in Figure 3 suggest that co-continuous structures come from not the coalescence of preformed dispersed particles, but the breakup of long PVDF fibers due to the shear effect and Laplace pressure. The PVDF/PLLA blend exhibits poor miscibility, leading to the formation of sea-island structures with the size of several microns. PVDF acts as the island phase due to the lower volume fraction, higher viscosity (shown in Figure S3) and resultant extremely low volume/viscosity ratio (≈0.03). This scenario is consistent with Scheme 1A and the SEM images shown in Figure 2D and 3A. When the reactive compatibilizer is added to the blend system in the mixer, a fraction of it migrates to the immiscible interface at the very beginning. The reaction between the epoxide group in RCC and the terminal carboxyl group of PLLA takes place (IR and Torque data shown as Figure S15 and S16), resulting in the grafted molecules of PLLA-g-PMMA. The PMMA side chains exhibit good entanglement with PVDF because of the excellent miscibility between them

17.

Subsequently, the comb-like

compatibilizer with double brushes along PMMA backbone has formed in-situ. The existence of the comb-like molecule can decrease the interface tension between PVDF 8

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and PLLA. This accounts for the smaller characteristic size and more interfaces (Scheme 1B), which makes it easier for compatibilizers to migrate to the “new” interface. At the same time, PVDF, PLLA and reactive compatibilizer are forced to deform into long fibers upon the shear effect, providing more chance for compatibilizers to react with PLLA at the interface. This is the reason for more comb-like molecules and further decrease of characteristic size. The migration of compatibilizers to the interface and the reduced structure size upon shear effect strengthen each other. As a result of this synergism effect, more and more compatibilizers migrate to the interface, resulting in the breakup of long PVDF fibers and the further decrease of interface tension and characteristic size (Figure 3C to 3E). At last, a considerable number of compatibilizers with double brushes locate at the interface, producing sub-100nm structures (Figure 3F and Scheme 1C). To clarify the reason for the occurrence of co-continuous structures in the case of extremely low volume/viscosity ratio, our attention should be paid to the following issues. Firstly, the reaction between PLLA and epoxide group leads to much higher viscosity of PLLA phase (shown in Figure S3) and the increase of volume/viscosity ratio of PVDF/PLLA, which is benefit to the formation of co-continuous structures. This result has good agreement with the conclusion from Paul and Barlow 30; secondly, a considerable number of compatibilizers have been localized at the interface because of the balanced stress on two sides of the side PMMA and the grafted PLLA chains. The systematical investigation on their localization and some evidences of this (concerning simulation, TEM and AFM-IR) will be discussed in future publications; thirdly, the poor interaction between PVDF/PLLA results in the repulsion effect of the binary brushes along PMMA backbone (Scheme 1D); finally, the PMMA backbone along interface and the repulsion effect of the binary brushes improve the interface curvature radius remarkably (Scheme 1E). As a result, we can find long fibers in Figure 3 and obtain co-continuous structures since interface curvature radius dominates the formation of them. In these structures, the localization of comb-like molecules is determined by the balanced stress on two sides and the lowest free energy of the blend system. Therefore, the co-continuous structures exhibit excellent 9

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thermal stability (Figure S9). On the contrary, the co-continuous structures prepared by means of phase inversion between the dispersed phases and the matrix are not stable since they are intermediate state. It is noteworthy that the adopted blend exhibiting extremely low volume/viscosity ratio is composed by commercially available components with very large molecular weight. The fabrication of co-continuous structure with the size of sub-100 nm in such system remains as one of the greatest challenge. Our result can serve as an effective solution for the key issue of co-continuous structures. In this work, PVDF/PLLA (30/70) has been adopted as a model system to investigate the formation of sub-100nm co-continuous structures in blend system with extremely low volume/viscosity ratio. PVDF tends to act as islands due to the lower volume fraction and higher viscosity. When reactive comb compatibilizers are mixed in the blend, the epoxide groups can react with the terminal carboxyl group of PLLA while the PMMA side chains exhibit excellent physical entanglement with PVDF, producing comb-like compatibilizers with double brushes which play important roles in the formation of sub-100nm co-continuous structures. On one hand, the comb-like compatibilizer with double brushes stabilizes its location at the interface because of the stress balance. This is the reason for the reduced interface tension, higher interface fraction and lower magnitude of the characteristic size; on the other hand, the PMMA backbones along immiscible interface and the repulsion effect of binary brushes result in the enlarged interface curvature radius, accounting for the occurrence of co-continuous structures.

Acknowledgment: This work was financially supported by the Zhejiang Natural Science foundation (LD19E030001), National Natural Science Foundation of China (21674033, 21104013), National Key R&D Program of China (2017YFB0307704) and Zhejiang Provincial Key R&D Program (2018C01038).

ASSOCIATED CONTENT Supporting Information Available: Information of materials and sample preparation, basic characterizations (including FTIR, GPC 10

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spectrum) of RCC, viscosity of components, acid hydrolysis efficiency, DSC of the blend, the photos, pore size measuremet, distribtution and thermal stability of self-supporting porous PVDF membranes, identification of matrix and island phase by solvent etching, the average size of phase-separated structures, torque evolution during melting belnd, optical properties of PLLA, PVDF and the blend with/without compatibilizers, the mechanical properties of PVDF/PLLA blends, and the thermal properties. (PDF) REFERENCES: (1) Sarazin, P.; Roy, X.; Favis, B. D. Controlled Preparation and Properties of Porous Poly(L-Lactide) Obtained from a Co-Continuous Blend of Two Biodegradable Polymers. Biomaterials 2004, 25 , 5965-5978. (2) Wiesenauer, B. R.; Gin, D. L. Nanoporous Polymer Materials Based on Self-Organized, Bicontinuous Cubic Lyotropic Liquid Crystal Assemblies and Their Applications. Polymer Journal 2012, 44 , 461-468. (3) Omonov, T. S.; Harrats, C.; Groeninckx, G. Co-Continuous and Encapsulated Three Phase Morphologies in Uncompatibilized and Reactively Compatibilized Polyamide 6/Polypropylene/Polystyrene Ternary Blends using Two Reactive Precursors. Polymer 2005, 46, 12322-12336. (4) Zolali, A. M.; Favis, B. D. Compatibilization and Toughening of Co-Continuous Ternary Blends via Partially Wet Droplets at the Interface. Polymer 2017, 114, 277-288. (5) Miles, I. S.; Zurek, A. Preparation, Structure and Properties of Two-Phase Co-Continuous Polymer Blends. Polymer 1988, 28, 796-805. (6) Jordhamo, G. M.; Manson, J. A.; Sperling, L. H. Phase Continuity and Inversion in Polymer Blends and Simultaneous Interpenetrating Networks. Polymer 1986, 26, 517-524. (7) Ren, D.; Tu, Z.; Yu, C.; Shi, H.; Jiang, T.; Yang, Y.; Shi, D.; Yin, J.; Mai, Y. W.; Li, R. K. Y. Effect of Dual Reactive Compatibilizers on the Formation of Co-Continuous Morphology of Low Density Polyethylene/Polyamide 6 Blends with Low Polyamide 6 Content. Ind Eng Chem Res 2016, 55, 4515-4525. (8) Nofar, M.; Maani, A.; Sojoudi, H.; Heuzey, M. C.; Carreau, P. J. Interfacial and Rheological Properties of PLA/PBAT and PLA/PBSA Blends and Their Morphological Stability under Shear Flow. J. Rheol 2015, 59, 317-333. (9) Zhang, C. L.; Feng, L. F.; Zhao, J.; Huang, H.; Hoppe, S.; Hu, G. H. Efficiency of Graft Copolymers at Stabilizing Co-Continuous Polymer Blends during Quiescent Annealing. Polymer 2008, 49, 3462-3469. (10) Pu, G.; Luo, Y.; Lou, Q.; Li, B. Co-Continuous Polymeric Nanostructures via Simple Melt Mixing of PS/PMMA. Macromol Rapid Comm 2009, 30, 133-137. (11) Pu, G.; Luo, Y.; Wang, A.; Li, B. Tuning Polymer Blends to Cocontinuous Morphology by Asymmetric Diblock Copolymers as the Surfactants. Macromolecules 2011, 44, 2934-2943. (12) Favis, B. D.; Chalifoux. J. P. Influence of Composition on the Morphology of Polypropylene/Polycarbonate Blends. Polymer 1988, 29, 1761. (13) Prashant, A. B.; Tsou, A. H.; Cheng, J.; Favis, B. D. Morphology Development and Interfacial Erosion in Reactive Polymer Blending. Macromolecules 2008, 41, 7549-7559. (14) You, W.; Yu, W. Onset Reduction and Stabilization of Cocontinuous Morphology in Immiscible Polymer Blends by Snowmanlike Janus Nanoparticles. Langmuir 2018, 34, 11

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11092-11100. (15) Dong, W.; Wang, H.; Ren, F.; Zhang, J.; He, M.; Wu, T.; Li, Y. Dramatic Improvement in Toughness of PLLA/PVDF Blends: the Effect of Compatibilizer Architectures. ACS Sustain Chem Eng 2016, 4, 4480-4489. (16) Dong, W.; Wang, H.; He, M.; Ren, F.; Wu, T.; Zheng, Q.; Li, Y. Synthesis of Reactive Comb Polymers and Their Applications as a Highly Efficient Compatibilizer in Immiscible Polymer Blends. Ind Eng Chem Res 2015, 54, 2081-2089. (17) Chen, H. M.; Wang, X. F.; Liu, D.; Wang, Y. P.; Yang, J. H.; Wang, Y.; Zhang, C. L.; Zhou, Z. W. Tuning the Interaction of an Immiscible Poly(Llactide)/Poly(Vinylidene Fluoride) Blend by Adding Poly(Methyl Methacrylate) via a Competition Mechanism and the Resultant Mechanical Properties. RSC Adv 2014, 4, 40569–40579. (18) Zolali, A. M.; Favis, B. D. Compatibilization and Toughening of Co-Continuous Ternary Blends via Partially Wet Droplets at the Interface. Polymer 2017, 114, 277-288. (19) Esquirol, A. L.; Sarazin, P.; Virgilio, N. Tunable Porous Hydrogels from Cocontinuous Polymer Blends. Macromolecules 2014, 47, 3068−3075. (20) Veenstraa, H.; Verkooijena, P. C. J.; Lenta, B. J. J. V.; Dama, J. V.; Boera, A. P. D.; Nijhofb, A. P. H. J. On the Mechanical Properties of Co-Continuous Polymer Blends: Experimental and Modelling. Polymer 2000, 41, 1817–1826. (21) Nishil, T.; Wang, T. T. Melting Point Depression and Kinetic Effects of Cooling on Crystallization in Poly(viny1idene fluoride)-Poly (methyl methacrylate) Mixtures. Macromolecules 1975, 8, 909-915. (22) Tang, T.; Huang, B. T. Interfacial Behaviour of Compatibilizers in Polymer Blends. Polymer 1994, 35, 281-285. (23) Jose, S.; Thomas, S.; Parameswaranpillai, J.; Aprem, A. S.; Karger-Kocsis, J. Dynamic Mechanical Properties of Immiscible Polymer Systems with and without Compatibilizer. Polymer Testing 2015, 44, 168-176. (24) Willemse, R. C.; Boer, A. P. D.; Dam, J. V.; Gotsis, A. D. Co-Continuous Morphologies in Polymer Blends: a New Model. Polymer 1998, 39, 5879–5887. (25) Macosko, C. W.; Guegan, Philippe.; Khandpur, A. K. Compatibilizers for Melt Blending: Premade Block Copolymers. Macromolecules 1996, 29, 5590-5599. (26) Li, J. M.; Ma, P. L.; Favis, B. D. The Role of the Blend Interface Type on Morphology in Co-continuous Polymer Blends. Macromolecules 2002, 35, 2005-2016. (27) Willemse, R. C.; Ramaker, E. J. J.; Dam, J. V.; Boer, A. P. D. Morphology Development in Immiscible Polymer Blends: Initial Blend Morphology and Phase Dimensions. Polymer 1999, 40, 6651–6659. (28) Sundararaj, U.; Dori, Y.; Macosko, W. C. Sheet Formation in Immiscible Polymer Blends: Model Experiments on Initial Blend Morphology. Polymer 1995, 36,1957-1968. (29) Sau, M.; Jana, S, C. A Study on the Effects of Chaotic Mixer Design and Operating Conditions on Morphology Development in Immiscible Polymer Systems. Polymer Engineering and Science 2004, 44, 407-422. (30) Paul, D. R.; Barlow, J. W. Polymer Blends and Alloys. Blackie Academic & Professional 1980, 18,109-168.

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