Synthesis and characterization of mesogen-jacketed liquid-crystal   polymers based on 2,5-bis(4 &apos;-alkoxyphenyl)styrene

doi:10.1002/pola.10689

CORC > 北京大学 > 化学与分子工程学院

	Synthesis and characterization of mesogen-jacketed liquid-crystal polymers based on 2,5-bis(4 '-alkoxyphenyl)styrene
	Yu, ZN ; Tu, HL ; Wan, XH ; Chen, XF ; Zhou, QF
刊名	journal of polymer science part a polymer chemistry
	2003
关键词	mesogen-jacketed liquid-crystal polymer 2,5-bis(4&apos poly [2,5-bis(4&apos terphenyl tail length liquid crystalline polymers (LCPs) synthesis radical polymerization FREE-RADICAL POLYMERIZATION CONFORMATIONAL ISOMERISM MOLECULAR-WEIGHT FLEXIBLE SPACER ACID TRANSITIONS POLYETHERS BEHAVIOR SYSTEMS SERIES -alkoxyphenyl)styrene -alkoxyphenyl)styrene]
DOI	10.1002/pola.10689
英文摘要	A series of novel mesogen-jacketed liquid-crystal polymers, poly[2,5-bis(4'-alkoxyphenyl)-styrene] (P-n, n = 1-11), were prepared via free-radical polymerization of newly synthesized monomers, 2,5-bis(4'-alkoxyphenyl)styrene (M-n, n = 1-11). The influence of the alkoxy tail length on the liquid-crystalline behaviors of the monomers and the polymers was investigated with differential scanning calorimetry (DSC), then mogravimetry, polarized optical microscopy (POM), and wide-angle X-ray diffraction (WAXD). The monomers with n = 1-4, 9, and 11 were monotropic nematic liquid crystals. All other monomers exhibited enantiotropic nematic properties. Their melting points (T-m's) decreased first as n increased to 6, after which T-m increased slightly at longer spacer lengths. The isotropic-nematic transition temperatures decreased regularly with increasing n values in an odd-even way. The glass-transition temperatures (T-g's) of the polymers first decreased as the tail lengths increased and then leveled off when n greater than or equal to 7. All polymers were thermally stable and entered the mesophase at a temperature above T-g. Upon further heating, no mesophase-to-isotropic melt transition was observed before the polymers decomposed. WAXD studies indicated that an irreversible order- order transition for the polymers with short tails (n less than or equal to 5) and a reversible order- order transition for those with elongated tails (n greater than or equal to 6) occurred at a temperature much higher than T-g. However, such a transition could not be identified by POM and could be detected by DSC only on heating scans for the polymers with long tails (n greater than or equal to 7). (C) 2003 Wiley Periodicals,; Polymer Science; SCI(E); EI; 45; ARTICLE; 10; 1454-1464; 41
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/255910]
专题	化学与分子工程学院
推荐引用方式 GB/T 7714	Yu, ZN,Tu, HL,Wan, XH,et al. Synthesis and characterization of mesogen-jacketed liquid-crystal polymers based on 2,5-bis(4 '-alkoxyphenyl)styrene[J]. journal of polymer science part a polymer chemistry,2003.
APA	Yu, ZN,Tu, HL,Wan, XH,Chen, XF,&Zhou, QF.(2003).Synthesis and characterization of mesogen-jacketed liquid-crystal polymers based on 2,5-bis(4 '-alkoxyphenyl)styrene.journal of polymer science part a polymer chemistry.
MLA	Yu, ZN,et al."Synthesis and characterization of mesogen-jacketed liquid-crystal polymers based on 2,5-bis(4 '-alkoxyphenyl)styrene".journal of polymer science part a polymer chemistry (2003).