Uniform to accelerated crystal twisting transition in deuterate polyethylene/poly(ethylene-alt-propylene) blend films

	Uniform to accelerated crystal twisting transition in deuterate polyethylene/poly(ethylene-alt-propylene) blend films
	Zhang, LN; Shi, WC; Han, CC; Cheng, H;程贺
刊名	CHINESE JOURNAL OF POLYMER SCIENCE
	2014
卷号	32 期号:9 页码:1260-1270
关键词	Polyethylene/poly(ethylene-alt-propylene) (d-PE/PEP) blend Phase separation Crystallization
英文摘要	A uniform to accelerated crystal twisting transition is observed in deuterate polyethylene/poly(ethylene-altpropylene) (d-PE/PEP) blend films. And the band period is a function of initial d-PE concentration, quench depth and annealing time of phase separation. As Keith and Padden suggested, twisting of lamella is due to the unbalanced stress on its both sides, which can supply a satisfying explanation to banded spherulites formed in homogeneous systems. When it comes to d-PE/PEP blend system, in homogeneous 99% d-PE/PEP (weight fraction of d-PE) blend film, the formation of banded spherulite is observed as a result of uniform twisting of ribbon like d-PE lamellae along the radial direction. With the amorphous PEP piling up, it transfers into accelerated edge-on to flat-on twisting due to crystallization assisted phase separation. The mechanism can be interpreted as following: d-PE molecules must inter-diffuse to the twisting growth front to continue the secondary nucleation and growth process. Meanwhile, the amorphous PEP molecules are rejected and accumulated at the twisting growth front. Once the d-PE lamella begins to twist because of unbalanced stress on both sides, the accumulated rubber phase at the growth front strengthens the unbalance and accelerates the edge-on to flat-on twisting. The concentration wave propagates further away with constant speed, and leads to concentric ring pattern with periodic nonuniform twisting along the radial direction. Since this is a kinetic effect, the band period can be controlled through initial d-PE concentration, quench depth and annealing time of phase separation. Our result shows that crystallization assisted phase separation can modify lamella growth kinetic pathway, thereby assisting concentric ring pattern formation.
学科主题	Polymer Science
收录类别	SCI
WOS记录号	WOS:000339881900016
公开日期	2016-05-03
内容类型	期刊论文
源URL	[http://ir.ihep.ac.cn/handle/311005/224893]
专题	高能物理研究所_东莞分部
推荐引用方式 GB/T 7714	Zhang, LN,Shi, WC,Han, CC,et al. Uniform to accelerated crystal twisting transition in deuterate polyethylene/poly(ethylene-alt-propylene) blend films[J]. CHINESE JOURNAL OF POLYMER SCIENCE,2014,32(9):1260-1270.
APA	Zhang, LN,Shi, WC,Han, CC,&Cheng, H；程贺.(2014).Uniform to accelerated crystal twisting transition in deuterate polyethylene/poly(ethylene-alt-propylene) blend films.CHINESE JOURNAL OF POLYMER SCIENCE,32(9),1260-1270.
MLA	Zhang, LN,et al."Uniform to accelerated crystal twisting transition in deuterate polyethylene/poly(ethylene-alt-propylene) blend films".CHINESE JOURNAL OF POLYMER SCIENCE 32.9(2014):1260-1270.