聚乳酸、乳酸-乙醇酸共聚物的流变性能  

On rheologic properties of polylactic acid and poly(lactic acid-co-glycolic acid)

作　　者：唐四叶[1] 张瑞[1] 林赛赛 TANG Si-ye;ZHANG Rui;LIN Sai-sai(College of Chemistry and Chemical Engineering,Luoyang Normal College,Luoyang 471934,Henan,China)

机构地区：[1]洛阳师范学院化学化工学院,河南洛阳471934

出　　处：《云南大学学报（自然科学版）》2022年第5期998-1004,共7页Journal of Yunnan University(Natural Sciences Edition)

基　　金：国家自然科学基金(21476102)。

摘　　要：采用旋转式黏度计测定了聚乳酸和乳酸-乙醇酸共聚物溶液在不同温度下不同质量分数时的黏度,计算了聚乳酸和乳酸-乙醇酸共聚物溶液的黏流活化能.结果表明:乳酸-乙醇酸共聚物溶液属于假塑性流体,其黏度随剪切速率的增加而减小;乳酸-乙醇酸共聚物溶液和聚乳酸溶液的黏度均随浓度的升高而增加,随温度的升高而减小,黏度与浓度之间均符合指数函数关系,黏度与温度之间均符合Arrhenius指数函数方程;聚乳酸和乳酸-乙醇酸共聚物溶液的黏流活化能基本上随浓度的升高而增大.溶液的黏流活化能越大,流动越困难,溶液的黏度对温度的变化越敏感;当溶剂、浓度一定时,乳酸-乙醇酸共聚物溶液的黏流活化能低于聚乳酸溶液的黏流活化能,乳酸-乙醇酸共聚物溶液的黏度比聚乳酸溶液低得多.这说明乳酸-乙醇酸共聚物与溶剂的相容性更好,乳酸-乙醇酸共聚物溶液比聚乳酸溶液更易流动.高分子与溶剂的相容性取决于分子结构.The viscosities of polylactic acid and poly(lactic acid-co-glycolic acid)solutions were determined by a rotary viscometer at different temperatures and concentrations,and the flow activation energies of polylactic acid and poly(lactic acid-co-glycolic acid)solutions were analyzed and calculated.The results show that the poly(lactic acid-co-glycolic acid)solutions exhibit the characteristics of pseudoplastic fluid and the viscosities of poly(lactic acid-co-glycolic acid)solutions decrease with the increase of theshear rate.The viscosities of poly(lactic acid-co-glycolic acid)and polylactic acid solutions increase with the increase of the concentration and decrease with the increase of the temperature.The exponential function can accurately reflect the relationship between viscosity and concentration of polylactic acid and poly(lactic acid-co-glycolic acid)solutions.The relationship between viscosity and temperature obeys the Arrhenius index function equation for polylactic acid and poly(lactic acid-co-glycolic acid)solutions.The flow activation energies of polylactic acid and poly(lactic acid-co-glycolic acid)solutions basically increase with the increase of concentration.The higher the flow activation energy of the solution,the more difficult the flow.And viscosity is the more sensitive to temperature variation.When the solvent and the concentration are certain,the flow activation energy of poly(lactic acid-co-glycolic acid)solution is lower than that ofpolylactic acid solution.The viscosity of poly(lactic acid-co-glycolic acid)solution is lower than that of polylactic acid solution.This demonstrates that the compatibility of poly(lactic acid-co-glycolic acid)and the solvent is better than that of polylactic acid,and this study also suggests that the liquidity of poly(lactic acid-coglycolic acid)solution is better than that of polylactic acidsolution.Compatibility of polymer and solvent depends on the molecular structure of the polymer.

关 键 词：聚乳酸 乳酸-乙醇酸共聚物 黏度 黏流活化能 

分 类 号：TQ311[化学工程—高聚物工业]