Difunctional initiator based on 1,3-diisopropenylbenzene. IV. Synthesis and modification of poly(alkyl methacrylate- b-styrene-b-butadiene- b-styrene-b-alkyl methacrylate (MSBSM)) thermoplastic elastomers
✍ Scribed by Y. S. Yu; Ph. Dubois; R. Jérôme; Ph. Teyssié
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 632 KB
- Volume
- 34
- Category
- Article
- ISSN
- 0887-624X
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✦ Synopsis
MSBSM five-block copolymers where B stands for butadiene, S for styrene, and M for either methyl methacrylate (MMA) or tert-butyl methacrylate (tBMA) have been synthesized by sequential anionic polymerization in a n apolar solvent by using a difunctional anionic initiator derived from 1,3-diisopropenylbenzene. These block copolymers show improved mechanical properties and a n extended service temperature compared to traditional SBS thermoplastic elastomers. Upon hydrolysis and further neutralization of the PolytBMA end-blocks, the upper glass transition temperature (T,) of the five-block copolymers has been raised up to about 150°C. A further increase in this service temperature (up to ca. 160°C) has resulted from the blending of sPMMA-SBS-sPMMA five-block copolymers with isotactic poly(methacry1ate) (iPMMA), due to the formation of a stereocomplex. The tensile properties of these modified five-block copolymers have remained essentially unchanged.