热塑性聚乙烯醇/乙烯-乙烯醇共聚物熔融挤出共混物制备及性能研究  

Study on the Preparation and Properties of Melt-Extruded TPVA/EVOH Blends

作　　者：李聪[1] 王洪学 白瑜[1] 周炳 李应成[1] LI Cong;WANG James Hongxue;BAI Yu;ZHOU Bing;LI Yingcheng(Shanghai Research Institute of Petrochemical Technology,SINOPEC,Shanghai 201208,China)

机构地区：[1]中国石油化工股份有限公司上海石油化工研究院,上海201208

出　　处：《化学反应工程与工艺》2022年第6期525-533,共9页Chemical Reaction Engineering and Technology

摘　　要：氢键作用对聚合物的共混改性影响显著,通过双螺杆挤出机熔融共混的方式,制备了不同质量比的热塑性聚乙烯醇(TPVA)/乙烯-乙烯醇共聚物(EVOH)的共混物,采用差示扫描量热仪(DSC)、动态热机械分析(DMA)、熔融指数仪和高压毛细管流变仪等研究共混物中氢键作用对热学性能及流变性能的影响。结果表明:共混物中TPVA与EVOH之间存在较强的氢键,TPVA与EVOH相容性较好但尚未完全混溶,彼此独立结晶,分别归属于TPVA和EVOH组分的结晶峰温度(T_(c))和熔融峰温度(T_(m))的变化与共混物的组成呈线性关系。共混物的熔体流动速率明显高于两种起始原料,呈现“熔体流动速率峰”现象;共混物体系的熔体黏度变化趋势与剪切速率密切相关,主要归因于体系中分子间氢键作用。Hydrogen bonding had a significant effect on the properties of polymer blends.Thermoplastic polyvinyl alcohol(TPVA)/ethylene-vinyl alcohol copolymer(EVOH)blends with different mass ratios were prepared by melt-blending extrusion with a twin-screw extruder.The effects of hydrogen bonding on the thermal and rheological properties of the blends were studied by differential scanning calorimetry(DSC),dynamic thermomechanical analysis(DMA),melt flow measurements and capillary rheology.The results showed the presence of strong hydrogen bonding between TPVA and EVOH.TPVA and EVOH in the blends were compatible but not miscible,both TPVA and EVOH crystallized independently.The changes of crystallization temperature(T_(c))and melting temperature(T_(m))as a function of EVOH content in the blends had linear relationships.The melt flow rates of the blends were significantly higher than those of the two starting materials and a"melt flow rate peak"phenomenon was observed.The apparent shear viscosities as a function of blend composition were dependent on the shear rates,which is possibly due to the strong intermolecular hydrogen bonding in the blends.

关 键 词：热塑性聚乙烯醇 乙烯-乙烯醇共聚物 结晶行为 熔体流动速率峰 分子间氢键 

分 类 号：TQ223.41[化学工程—有机化工]