Thermotropic and chiroptical properties of poly {(+)-2,5-bis[4-((S)-2-methylbutoxy)phenyl] styrene} and its random copolymer with polystyrene

doi:10.1021/ma071141p

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	Thermotropic and chiroptical properties of poly {(+)-2,5-bis[4-((S)-2-methylbutoxy)phenyl] styrene} and its random copolymer with polystyrene
	Liu, Anhua; Zhi, Junge; Cui, Jiaxi; Wan, Xinhua; Zhou, Qifeng
刊名	MACROMOLECULES
	2007-11-13
卷号	40 期号:23 页码:8233-8243
ISSN号	0024-9297
DOI	10.1021/ma071141p
英文摘要	Poly {(+)-2,5-bis [4-((S)-2-methylbutoxy)phenyl] styrene} (PMBPS) and its random copolymers with polystyrene were synthesized via atom transfer radical polymerization and conventional radical copolymerization, respectively. The dependences of thermotropic and chiroptical properties on the degrees of polymerization (DPs) of homopolymers and on the compositions of copolymers were investigated to correlate the liquid crystallinity and helical chain structure of PMBPS. When DP < 53, PMBPS revealed no mesophase; when 53 < DP < 80, the polymer formed columnar nematic (Phi(N)) phase; whereas, when DP >= 80, hexatic columnar nematic (Phi(HN)) phase was generated. The monomer MBPS displayed positive optical rotation, while the oligomers and polymers showed negative optical rotations. The strength intensified with DP and leveled off at DP = 53, suggesting a stable helix started. The random nature of copolymers was indicated by the reactivity ratios of two monomers (r(MBPS) = 0.67, r(St) = 0.98), and further supported by smooth variation of single glass transition temperature. When the feed molar fraction of MBPS (x) was less than 59%, the optical rotations of copolymers were positive and scaled linearly with the proportion of chiral monomer, implying no new chiral. structure developed. When x > 59%, the optical rotations decreased with increasing MBPS content and finally became negative when x reached above 90%, suggesting the MBPS segment was long enough to develop a dominating helical structure with negative optical rotation. Among all the copolymers, only one with x value of as high as 99% could achieve mesophase ((Phi(N)). It was considered that a long enough helical structure, which acted as cylindrical building blocks, was the origin of PMBPS to form a liquid crystalline phase.
语种	英语
出版者	AMER CHEMICAL SOC
WOS记录号	WOS:000250801700018
内容类型	期刊论文
源URL	[http://ir.iccas.ac.cn/handle/121111/60937]
专题	中国科学院化学研究所
通讯作者	Wan, Xinhua
作者单位	Peking Univ, Coll Chem & Mol Engn, Key Lab Polymer Chem & Phys MOE, Beijing Natl Lab Mol Sci, Beijing 100871, Peoples R China
推荐引用方式 GB/T 7714	Liu, Anhua,Zhi, Junge,Cui, Jiaxi,et al. Thermotropic and chiroptical properties of poly {(+)-2,5-bis[4-((S)-2-methylbutoxy)phenyl] styrene} and its random copolymer with polystyrene[J]. MACROMOLECULES,2007,40(23):8233-8243.
APA	Liu, Anhua,Zhi, Junge,Cui, Jiaxi,Wan, Xinhua,&Zhou, Qifeng.(2007).Thermotropic and chiroptical properties of poly {(+)-2,5-bis[4-((S)-2-methylbutoxy)phenyl] styrene} and its random copolymer with polystyrene.MACROMOLECULES,40(23),8233-8243.
MLA	Liu, Anhua,et al."Thermotropic and chiroptical properties of poly {(+)-2,5-bis[4-((S)-2-methylbutoxy)phenyl] styrene} and its random copolymer with polystyrene".MACROMOLECULES 40.23(2007):8233-8243.