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Novel smart thermoplastic elastomers (TPEs) with very high extensibility were prepared by blending polyvinylidene fluoride (PVDF) with hydrogenated nitrile rubber (HNBR) at an appropriate ratio, and their processing–structure–property relationship was investigated. Although the rubber phase was found to be dispersed in the matrix of PVDF for all compositions, morphology was shear sensitive and changed significantly after each processing step. Dropletlike structure was observed after the mixing in an internal mixer and compression molding, which changed to the lamellar structure after milling and injection molding. The compression molded sample exhibited very high extensibility (∼1600% elongation at break for 30/70 PVDF/HNBR blend) and a tensile strength of ∼6 MPa due to the formation of a strong interface. The elongation at break was much higher than any of the TPEs reported so far. Theoretical calculation of rubber particle size was also in agreement with the experimental observation. Dissipative particle dynamics simulation was run to capture the morphology, where HNBR chains were more sensitive to the shear force than the PVDF chains. The electromechanical sensitivity of the blend was 14.3 MPa−1, much better than the existing reported elastomeric actuator as well as pristine PVDF. Dynamic vulcanization gave further improvement in tensile strength and tension set properties.

Visualization of polymer molecules by molecular dynamics simulation remains a challenging area in molecular modeling, as it involves a number of factors like type of force field, simulation time, simulation steps, and so forth. In our present study, we have used the condensed‐phase optimized molecular potentials for atomistic simulation studies (COMPASS) force field, which is specific for polymers and organic molecules, in order to visualize the macromolecular chains of various flexible amorphous polymers: natural rubber, polybutadiene rubber, styrene–butadiene rubber, nitrile rubber, polychloroprene rubber, and fluoroelastomer. The study covered a wide range from nonpolar rubbers to polar rubbers, and the COMPASS force field was promising to understand the local structure and the packing of the chains inside the simulation box. The distance between different adjacent pairs of carbon atoms within the polymer chains was discussed in detail from intramolecular radial distribution function and represented pictorially in the polymer chains. Various bond angles were also examined for further details. In addition, interchain contacts, glass‐transition temperature, and solubility parameter were predicted and compared with the experimental values. The diffusive characteristic of the chains was assessed by mean square displacement which in turn described the polymer chain mobility. In essence, the present study is expected to aid in the vivid conceptualization of molecular orientation of various polymers and would help in predicting various physical properties. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47457

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A series of high-temperature thermoplastic elastomers (TPEs) and thermoplastic vulcanisates (TPVs) were successfully developed based on two different types of heat resistant polyamide (PA) (25 parts by weight)-PA-12 and PA-6, in combination with three different functionalized rubbers (75 parts by weight) of varying polarity, e.g., maleic anhydride grafted ethylene propylene diene terpolymer (MA-g-EPDM), sulphonated ethylene propylene diene terpolymer, and carboxylated acrylonitrile butadiene rubber, by melt mixing method. These rubbers have low level of unsaturation in its backbone, and the plastics showed high melting range. Thus, the developed TPEs and TPVs were expected to be high temperature resistant. Resol type resin was used for dynamic vulcanization to further increase the high temperature properties of these blends. Interestingly, initial degradation temperature of the prepared blends was much higher (421 8C for MA-g-EPDM/PA-12) than the other reported conventional TPEs and TPVs. Fourier transform infrared analysis described the interactive nature of the TPEs and TPVs, which is responsible for their superior properties. The maximum tensile strength with lowest tension set was observed for the carboxylated acrylonitrile butadiene rubber/PA-12 TPV. Mild increase in mechanical properties without any degradation was observed after recycling. Dynamic mechanical analysis results showed two distinct glass transition temperatures and indicated the biphasic morphology of the blends, as evident from the scanning electron microscopy.