Synthesis and characterization of novel rod-coil diblock copolymers of poly(methyl methacrylate) and liquid crystalline segments of poly(2,5-bis[(4-methoxyphenyl)oxycarbonyl] styrene)
| Autor: | Xinhua Wan, Hailiang Zhang, E. M. Woo, Qi-Feng Zhou, Xiaofang Chen |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Materials science
Polymers and Plastics Atom-transfer radical-polymerization Organic Chemistry Radical polymerization Poly(methyl methacrylate) Styrene chemistry.chemical_compound chemistry visual_art Polymer chemistry Materials Chemistry visual_art.visual_art_medium Copolymer Molar mass distribution sense organs Methyl methacrylate Glass transition |
| Zdroj: | Polymer International. 52:92-97 |
| ISSN: | 1097-0126 0959-8103 |
| DOI: | 10.1002/pi.1037 |
| Popis: | Liquid crystalline diblock copolymers with different molecular weights and low poly- dispersities were synthesized by atom transfer radical polymerization of methyl methacrylate (MMA) and 2,5-bis((4-methoxyphenyl)oxycarbonyl)styrene (MPCS) monomers. The block architecture (coil- conformation of MMA segment and rigid-rod of MPCS segment) of the copolymer was experimentally confirmed by a combination of 1 H nuclear magnetic resonance and gel permeation chromatograph techniques. The liquid crystalline behaviour of the copolymer was studied using differential scanning calorimetry and polarized optical microscope. It was found that the liquid crystalline behaviour was dependent on the number average molecular weight of the rigid segment. Only those copolymers with M n(GPC) of the rigid block above 9200g mol � 1 could form liquid crystalline phases higher than the glass transition temperature of the rigid block. The random copolymers MPCS-co-MMA were also synthesized by conventional free radical polymerization. The molar content of MPCS in MPCS-co- MMA had to be higher than 71% to maintain liquid crystalline behaviour. # 2003 Society of Chemical Industry |
| Databáze: | OpenAIRE |
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