摘要
采用挤出发泡的方法制备了聚乙烯醇(PVA)/淀粉(St)泡沫,研究了机头压力、淀粉含量和成核剂二氧化硅(SiO_(2))对泡孔结构的影响,探索了定应变和变应变下泡沫的压缩特能。结果表明,挤出发泡棒材泡孔尺寸从中心到边缘呈梯度递减的趋势,提高转速能有效增大模头熔体压力、减小泡孔尺寸、提高泡孔密度。通过控制淀粉和SiO_(2)含量可调控泡沫的泡孔结构,提高SiO_(2)含量可使泡沫具有更加均匀的泡孔结构、更小的泡孔直径,而提高淀粉含量可使PVA/St材料的熔体黏度下降、泡孔结构均匀性下降、泡孔壁增厚。循环压缩结果表明,增加淀粉和SiO_(2)含量可以增强泡沫的压缩强度,当淀粉质量分数为30%、SiO_(2)质量分数为3%时,泡沫压缩强度达到350 KPa、回弹率达到89.4%。泡沫的能量吸收量和吸能效率随淀粉含量的增加而上升,但在定应变模式下,随循环次数增加而下降,随应变的增加而上升。
Polyvinyl alcohol(PVA)/starch foams were prepared by extrusion foaming.The effects of head pressure,starch content and nucleating agent silicon dioxide(SiO_(2))content on the cell structure were investigated,and the compressive properties of the foams were studied at the constant and variable strains.The results show that the size of extruded foamed bars show a gradient decreasing from the center to the edge,and the melt pressure of the die head could be increased effectively by increasing the rotational speed to reduce the size and increase the density of cell.By controlling the starch and SiO_(2) content,the cell structure of the foams was controlled.Increasing the SiO_(2) content results in a more uniform cell structure and smaller cell diameter,while increasing the starch content decreases the viscosity of the PVA/starch melt,decreases the uniformity of the cell structure and makes the cell wall thicken.The cyclic compression results show that increasing the starch and SiO_(2) content could enhance the compressive strength of the foams,and when the starch mass fraction is 30%and the SiO_(2) mass fraction is 3%,the compressive strength of the foam reaches 350 kPa and the resilience reaches 89.4%.The energy absorption and energy absorption efficiency of the foam are increased with the increase of starch content,but decrease with the increase of cycle times and increase with the increase of strain in the constant strain mode.
作者
张世豪
杜俊威
胡园园
鲍昊凡
刘清亭
张荣
付旭东
胡圣飞
Shihao Zhang;Junwei Du;Yuanyuan Hu;Haofan Bao;Qingting Liu;Rong Zhang;Xudong Fu;Shengfei Hu(Hubei Provincial Key Laboratory of Green Materials for Light Industry,New Materials and Green Manufacturing Talent Introduction and Innovation Demonstration Base,Hubei University of Technology,Wuhan 430068,China)
出处
《高分子材料科学与工程》
EI
CAS
CSCD
北大核心
2023年第3期88-95,共8页
Polymer Materials Science & Engineering
基金
湖北省重点研发计划(2021BGD018)。
关键词
聚乙烯醇
淀粉
泡孔结构调控
压缩性能
polyvinyl alcohol
starch
cell structure controlling
compression properties
