摘要
通过选取若干温度对聚甲基丙烯酸甲酯(PMMA)试样进行应力松弛实验,结合实验数据,建立松弛速率-温度(p-T)指数模型,计算不同T下PMMA的p和松弛时间常数(τ);以积分的形式建立起可连续求解的聚合物松弛应力变化率-冷却速率[σ_Δ(t)-v(t)]模型,求解不同v(t)下聚合物的σ_Δ(t),同时进行prism微结构类固态热压印实验,通过比较模型计算结果与微结构复制率,验证σ_Δ(t)-v(t)模型的实用性。结果表明,随着v(t)的提高,σ_Δ(t)越来越小,内应力松弛的更加充分,微结构的成型精度越高。
This paper reported an investigation on the relationship between cooling rate and relaxation rate of poly(methyl methacrylate)(PMMA)during the micro hot embossing process in a solid-like state.A relaxation-rate-temperature index model was established on the basis of the experimental data of stress relaxation of PMMA at different temperature,and then the relaxation rate and relaxation time constants of PMMA at different temperatures were calculated. A relaxation stress rate-cooling rate equation was determined for PMMA in an integral form,which could continuously obtain the relaxation stress rate at different cooling rates. A prism microstructural hot embossing experiment was conduced to verify the practicality of stress ratecooling rate model through the comparison of the theoretical and experimental results.The results indicated that the relaxation stress rate became smaller with an increase of cooling rate,and the internal stress gained a more sufficient relaxation.This led to a higher molding accuracy for the microstructure.
出处
《中国塑料》
CSCD
北大核心
2017年第12期78-83,共6页
China Plastics
关键词
应力松弛
冷却速率
松弛速率
类固态微热压印
聚甲基丙烯酸甲酯
stress relaxation
cooling rate
relaxation rate
micro hot embossing in solid state
poly(methyl methacrylate)
