超高分子量聚乙烯模塑板材的抗冲击机制  

Impact Resistance Mechanism of Ultra-high Molecular Weight Polyethylene Molded Sheet

作　　者：宋新月 魏悦 沈杰 施德安 杨华伟[1,2] 栾世方[1,2] SONG Xinyue;WEI Yue;SHEN Jie;SHI Dean;YANG Huawei;LUAN Shifang(School of Applied Chemistry and Engineering,University of Science and Technology of China,Hefei 230026,China;State Key Laboratory of Polymer Physics and Chemistry,Changchun Institute of Applied Chemistry,Chinese Academy of Sciences,Changchun 130022,China;WEGO Group Co.,Ltd.,Weihai 264209,China;Hubei Key Laboratory of Polymer Materials,School of Materials Science and Engineering,Hubei University,Wuhan 430062,China)

机构地区：[1]中国科学技术大学应用化学与工程学院,合肥230026 [2]中国科学院长春应用化学研究所,高分子物理与化学国家重点实验室,长春130022 [3]威高集团有限公司,威海264209 [4]湖北大学材料科学与工程学院,高分子材料湖北省重点实验室,武汉430062

出　　处：《高等学校化学学报》2023年第4期180-189,共10页Chemical Journal of Chinese Universities

基　　金：国家重点研发计划项目(批准号:2020YFC1106903)资助。

摘　　要：超高分子量聚乙烯(UHMWPE)是一种具有突出抗冲击特性的高性能工程塑料,有关其合成、加工和应用的研究是现今高分子科学的研究热点之一,但是UHMWPE抗冲击的内在机制仍未明确.本文选取黏均分子量约为5×10^(6),悬臂梁双缺口冲击强度分别为54.7,93.4,105和152 kJ/m^(2)的4种UHMWPE为研究对象,通过分子结构和凝聚态结构表征,探究了UHMWPE的抗冲击机理.研究发现,4种UHMWPE具有相同的晶型、接近的结晶度和片晶厚度;UHMWPE在微观上表现出重复性的“延展-断裂”式的抗冲击过程,“延展-断裂”条带的数量和宽度与冲击强度正相关;非晶区的缠结密度与冲击强度呈线性负相关关系,相关性指数高达0.9,即在UHMWPE的合成和加工过程中,控制非晶区的缠结密度对最终制品的抗冲击强度至关重要.Ultra-high molecular weight polyethylene(UHMWPE)is an high performance engineering plastic with superior impact resistance,and the studies about its synthesis,processing and application have been a hot topic in modern polymer science,however,the mechanism behind its superior impact resistance is still unclear.In this work,four UHMWPE samples with viscosity average molecular weight around 5×10^(6)and impact strength from 54.7 to 152 kJ/m^(2)were studied in order to reveal the impact resistance mechanism of UHMWPE.It is found that under the same compression molding conditions,the four UHMWPE samples have the same crystal form,similar crystallinity and lamellar thickness.During the impact strength test,the UHMWPE sheets show a characteristic repetitive“extension-fracture”anti-impact behavior,and the number and width of extended bands are positively correlated with the impact strength.It is also discovered that the entanglement density of the amorphous phase is negatively and linearly correlated with the impact strength with a goodness-of-fit as high as 0.9.Thus it can be concluded that control⁃ling the entanglement of UHMWPE during its synthesis and processing procedure is really crucial to the impact strength.

关 键 词：超高分子量聚乙烯 冲击强度 层状堆积结构 链缠结 

分 类 号：O631[理学—高分子化学]