Formation of Shish-Kebabs in Injection-Molded Poly(L-lactic acid) by Application of an Intense Flow Field

doi:10.1021/am3019756

CORC > 化学研究所 > 中国科学院化学研究所

	Formation of Shish-Kebabs in Injection-Molded Poly(L-lactic acid) by Application of an Intense Flow Field
	Xu, Huan 1; Zhong, Gan-Ji 1; Fu, Qiang 1; Lei, Jun 1; Jiang, Wei 2; Hsiao, Benjamin S.3; Li, Zhong-Ming 1
刊名	ACS APPLIED MATERIALS & INTERFACES
	2012-12-01
卷号	4 期号:12 页码:6773-6783
关键词	Shish-kebabs Poly(L-lactic Acid) Intense Shear Flow Polymorphism Bamboo-like Structure Performance
ISSN号	1944-8244
DOI	10.1021/am3019756
英文摘要	Unlike polyolefins (e.g., isotactic polypropylene), it is still a great challenge to form rich shish-kebabs in biodegradable poly(L-lactic acid) (PLLA) because of its short chain length and semirigid chain backbone. In the present work, a modified injection molding technology, named oscillation shear injection molding, was applied to provide an intense shear flow on PLLA melt in mold cavity, in order to promote shear-induced crystallization of PLLA. Additionally, a small amount of poly(ethylene glycol) (PEG) with flexible chains was introduced for improving the crystallization kinetics. Numerous shish-kebabs of PLLA were achieved in injection-molded PLLA for the first time. High-resolution scanning electronic microscopy and small-angle X-ray scattering showed a structure feature of shish-kebabs with a diameter of around 0.7 mu M and a long period of similar to 20 nm. The wide-angle X-ray diffraction results showed that shish-kebabs had more ordered crystalline structure of alpha-form. A significant improvement of the mechanical properties was obtained; the tensile strength and modulus increased to 733 and 1888 MPa from the initial values of 64.9 and 1684 MPa, respectively, meanwhile the ductility is not deteriorated. Interestingly, when shish-kebabs form in the PLLA/PEG system, a bamboo like bionic structure comprising a hard skin layer and a soft core develops in injection molded specimen. This unique structure leads to a great balance of mechanical properties, including substantial increments of 26, 20, and 112% in the tensile strength, modulus, and impact toughness, compared to the control sample. Further exploration will give a rich fundamental understanding in the shear induced crystallization and morphology manipulation of PLLA, aiming to achieve superior PLLA products.
语种	英语
出版者	AMER CHEMICAL SOC
WOS记录号	WOS:000313149800051
内容类型	期刊论文
源URL	[http://ir.iccas.ac.cn/handle/121111/48691]
专题	中国科学院化学研究所
通讯作者	Zhong, Gan-Ji
作者单位	1.Sichuan Univ, State Key Lab Polymer Mat Engn, Coll Polymer Sci & Engn, Chengdu 610065, Sichuan, Peoples R China 2.Chinese Acad Sci, Changchun Inst Appl Chem, State Key Lab Polymer Phys & Chem, Changchun 130022, Peoples R China 3.SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA
推荐引用方式 GB/T 7714	Xu, Huan,Zhong, Gan-Ji,Fu, Qiang,et al. Formation of Shish-Kebabs in Injection-Molded Poly(L-lactic acid) by Application of an Intense Flow Field[J]. ACS APPLIED MATERIALS & INTERFACES,2012,4(12):6773-6783.
APA	Xu, Huan.,Zhong, Gan-Ji.,Fu, Qiang.,Lei, Jun.,Jiang, Wei.,...&Li, Zhong-Ming.(2012).Formation of Shish-Kebabs in Injection-Molded Poly(L-lactic acid) by Application of an Intense Flow Field.ACS APPLIED MATERIALS & INTERFACES,4(12),6773-6783.
MLA	Xu, Huan,et al."Formation of Shish-Kebabs in Injection-Molded Poly(L-lactic acid) by Application of an Intense Flow Field".ACS APPLIED MATERIALS & INTERFACES 4.12(2012):6773-6783.