Molecular Aggregation States and Physical Properties of Syndiotactic Polystyrene/Hydrogenated Polyisoprene Multiblock Copolymers with Crystalline Hard Domain

Abstract

Molecular aggregation structure and mechanical as well as thermal properties of novel well-defined multiblock copolymers consisting of crystalline syndiotactic polystyrene (sPS) and rubbery hydrogenated polyisoprene (hPIp) were investigated. The morphology and crystalline ordered structure of the multiblock copolymer films prepared by solvent casting from 1,2-dichlorobenzene solution depended on the volume fraction of sPS (VF sPS ) and number of blocks. The multiblock copolymer films exhibited ordered morphology with low crystallinity. The crystallinity of the sPS reduced with decreasing the VF sPS . The pentablock copolymer produced more ordered morphology and less crystallinity than the triblock copolymers. The anisotropic orientation and mechanical stability of the δ form sPS crystals in the spherical sPS domains during uniaxial stretching were demonstrated. Tensile testing and dynamic mechanical analysis indicated that these multiblock copolymer films with appropriate sPS fraction are strong, tough, and elastic and thus could be potential candidates for a new type of thermoplastic elastomer with discrete crystalline hard domains.

In Situ Synchrotron Radiation X-ray Scattering Investigation of a Microphase-Separated Structure of Thermoplastic Elastomers under Uniaxial and Equi-Biaxial Deformation Modes

“…The orientation of the PEB chains during sample deformation is also crucial for understanding the mechanical properties of the material. In situ small-angle X-ray scattering (SAXS) − and wide-angle X-ray scattering (WAXS) techniques − are powerful methods to investigate the arrangement and deformation behavior of PS domains as well as the orientation state of the PEB chains. Many studies have reported on the deformation behavior of various types of thermoplastic elastomers based on these techniques.…”

A New Strategy to Synthesize α,ω‐Dihydroxy Multiblock Copolymers via [CpRu(CH3CN)3]PF6/Quinaldic Acid Catalyst

“…Multiblock copolymers (MBCs) containing random (ABBAAB) and alternating (ABABAB) segments have attracted significant scientific interest, owing to their resulting microphase‐separated morphologies, different thermal and mechanical properties with a growing list of realized and potential applications . Currently, major sy nthesis methods to get MBCs relying on polycondensation can be divided into two categories, that is, click chemistry and coupling chemistry of α,ω‐dihydroxy to form urethane, ester, or amide bonds .…”

“…Currently, major sy nthesis methods to get MBCs relying on polycondensation can be divided into two categories, that is, click chemistry and coupling chemistry of α,ω‐dihydroxy to form urethane, ester, or amide bonds . Although some of the MBCs have been successfully prepared and got some applications, those MBCs were mainly focused on thermoplastic materials with superior performance . Therefore, having a special terminal groups of MBCs which can be used as thermosetting material were not yet received much attention and research.…”

“…[6][7][8][9][10][11][12] Although some of the MBCs have been successfully prepared and got some applications, those MBCs were mainly focused on thermoplastic materials with superior performance. [13][14][15][16][17][18][19][20][21][22] Therefore, having a special terminal groups of MBCs which can be used as thermosetting material were not yet received much attention and research. As is well known, the preparation of α,ωdihydroxy polymers has been a hot subject of investigation for several decades owing to their diverse applications in the fields of adhesives and biomedical and elastomeric materials.…”

Structural origin for the strain rate dependence of mechanical response of fluoroelastomer F2314

“…Imposing deformation on TPEs may induce complex structural evolutions simultaneously, such as deformation of microphase‐separated domains, crystallization in soft domains, melting or phase transition in hard domains, and so forth . These structural evolutions can be tracked with in situ small‐ and wide‐angle X‐ray scattering (SAXS/WAXS) techniques . For example, with in situ SR WAXS during cyclic tensile deformation on polyamide 12 (PA12) and polytetrahydrofuran segmented copolymers, a reversible transformation between the stable γ phase to the metastable α″ phase of PA12 is observed, which may contribute somewhat to their elasticity .…”