Retardance of Form II to Form I Transition in Polybutene-1 at Late Stage: A Proposal of a New Mechanism

doi:10.1021/acs.macromol.7b02481

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	Retardance of Form II to Form I Transition in Polybutene-1 at Late Stage: A Proposal of a New Mechanism
	Qiao, Yongna 1,2; Wang, Hai 1; Men, Yongfeng 1,2
刊名	MACROMOLECULES
	2018-03-27
卷号	51 期号:6 页码:2232-2239
ISSN号	0024-9297
DOI	10.1021/acs.macromol.7b02481
英文摘要	The retardation of polybutene-1 form II to form I transition in the late stage has been investigated by means of time-resolved wide-angle X-ray diffraction. Form II samples with different lamellar thickness and constituent in amorphous phase were generated via varying crystallization temperature and molecular weight and aged at room temperature for the form II to form I transition. The II to I polymorphic transition in polybutene-1 undergoes two stages, where slow nucleation and rapid growth proceed in the first stage and extremely slow secondary nucleation and growth take place in the late stage. The degree of transition reaches a plateau value in the late stage of transition, which depends highly on crystallization temperature and molecular weight that low molecular weight and high crystallization temperature always contribute to a greater degree of transition, but is less affected by the kinetics in the first stage. According to the crystal unit cell parameters of form II and form I, there should be an extension in the normal direction of lamellae and a shrinkage in the lateral direction during phase transition, which thus would induce an additional pressure in the normal direction and the tendency to expansion in the lateral direction on the residual from II crystallites. As a result, the nucleation and further growth of the II to I transition are retarded. Low molecular weight and high crystallization temperature lead to larger content of chain ends and higher chain mobility in the amorphous phase; hence, the samples are more likely to release the unfavorable factors restraining generation of form I nuclei to some extent. The transition degree in late stage is thus an intrinsic property of PB-1 samples determined by their microstructures and would not be influenced by the transition behavior in the first stage.
语种	英语
出版者	AMER CHEMICAL SOC
WOS记录号	WOS:000428712300010
内容类型	期刊论文
源URL	[http://ir.iccas.ac.cn/handle/121111/46159]
专题	中国科学院化学研究所
通讯作者	Men, Yongfeng
作者单位	1.Chinese Acad Sci, Changchun Inst Appl Chem, State Key Lab Polymer Phys & Chem, Renmin St 5625, Changchun 130022, Jilin, Peoples R China 2.Univ Sci & Technol China, Hefei 230026, Anhui, Peoples R China
推荐引用方式 GB/T 7714	Qiao, Yongna,Wang, Hai,Men, Yongfeng. Retardance of Form II to Form I Transition in Polybutene-1 at Late Stage: A Proposal of a New Mechanism[J]. MACROMOLECULES,2018,51(6):2232-2239.
APA	Qiao, Yongna,Wang, Hai,&Men, Yongfeng.(2018).Retardance of Form II to Form I Transition in Polybutene-1 at Late Stage: A Proposal of a New Mechanism.MACROMOLECULES,51(6),2232-2239.
MLA	Qiao, Yongna,et al."Retardance of Form II to Form I Transition in Polybutene-1 at Late Stage: A Proposal of a New Mechanism".MACROMOLECULES 51.6(2018):2232-2239.