摘要
以聚丙烯(PP)为基体,碳酸氢钠(NaHCO3)为发泡剂,采用精确二次开模注塑成型工艺制备微发泡PP材料,系统考察了微开模距离对微发泡PP材料密度和力学性能的影响。结果表明,随着微开模距离的增加,微发泡PP样品的密度、拉伸屈服强度、弯曲强度和断裂伸长率都呈现相似的指数级降低趋势,微发泡PP样品的缺口冲击强度明显低于未发泡PP样品。当微开模距离为0.53mm时,微发泡PP样品的密度为0.813g/cm^3,拉伸屈服强度为12.7MPa,弯曲强度为16.6MPa,断裂伸长率为18.3%,缺口冲击强度为10.6kJ/m^2,与未发泡PP样品的缺口冲击强度31.0kJ/m^2相比,缺口冲击强度保持率仅为34%;随着微开模距离的增加,微发泡PP样品的弯曲弹性模量呈线性降低,比弯曲弹性模量随着微开模距离的增加呈现先增大后减小的趋势。当微开模距离为0.50~0.70mm时,可获得较为均一的泡孔结构,微发泡PP样品的比弯曲弹性模量最佳,同时材料减重幅度高达21%~28%。当微开模距离为0.61mm时,比弯曲弹性模量达到最大值,为1682N/m^2,相对于未发泡PP样品的1408N/m2提高了19.5%,同时材料减重幅度为26%。
The microcellular polypropylene (PP) was prepared by the method of precise secondary injection molding with the PP using as the matrix and the sodium bicarbonate (NaHCO3) using as the foaming agent. The effects of the micro-opening distance on the density and mechanical properties were systematically investigated. The results show that the density,tensile yield strength, bending strength and elongation at break of the microcellular PP decrease in the similar exponential trend as the micro-opening distance increases. The notched impact strength of the microcellular PP is lower than that of the pure PP. When the micro-opening distance is 0.53 mm,the density,tensile yield strength,bending strength and elongation at break of the microcellular PP are 0.813 g/ cm^3,12.7 MPa,16.6 MPa and 18.3% respectively,and the notched impact strength of the microcellular PP is 10.6 kJ/m^2 which is 34% of the notched impact strength of pure PP of 31.0 kJ/m^2. With the micro-opening distance increasing,the bending modulus of microcellular PP decreases linearly and the specific bending modulus of microcellular PP increases firstly and then decreases. When micro-opening distance is between 0.50 –0.70 mm,the pore structure is more uniform,the specific bending modulus of microcellular PP is optimum,and the weight reduction of the material can reach 21%–28%. The specific bending modulus of microcellular PP reaches the maximum value of 1 682 N/m^2 which increases at 19.5% compared with the 1 408 N/m^2 of the pure PP,and the weight reduction of the material is 26% when the micro-opening distance is 0.61 mm.
作者
蒋团辉
曾祥补
张翔
李胜男
何力
段于喜
Jiang Tuanhui;Zeng Xiangbu;Zhang Xiang;Li Shengnan;He Li;Duan Yuxi(National Engineering Research Center for Compounding and Modification of Polymer Materials,Guiyang 550022,China;Liuzhou Wuling Automobile Industry Co.,Ltd.,Liuzhou 545005,China)
出处
《工程塑料应用》
CAS
CSCD
北大核心
2019年第6期60-65,共6页
Engineering Plastics Application
基金
贵州省科技计划项目{黔科服企[2018]4010号,黔科合基础[2019]1176号,黔科合基础[2016]1077号,黔科合平台人才[2017]5731号}
贵阳市白云区科技计划项目{白科合同[2018]8号,白科合同[2018]9号}
关键词
注塑微发泡
微开模距离
聚丙烯
力学性能
injection microcellular foaming
micro-opening distance
polypropylene
mechanical property
作者简介
通讯作者:何力,教授,博士生导师,主要从事聚合物微发泡研究。E-mail :prcheli@163.com.
