耐热聚乙烯管材料的支化结构研究

Study on Branching Structure of Polyethylene of Raised Temperature Resistance Pipe Material

通过核磁共振碳谱、动态流变仪、差示扫描量热仪等对基本性能指标相近的国产和进口耐热聚乙烯(PE-RT)管材料的支化结构进行了研究。结果表明:国产和进口PE-RT管材料熔体流动速率和密度相当,力学性能接近,国产料刚性稍高,韧性略低,相对分子质量略低,相对分子质量分布略宽。与进口料相比,国产PE-RT管材料的共聚单体含量低,平均乙烯序列长度略高,平均丁烯序列长度略低,导致其黏流活化能低于进口料的。国产料高温熔融峰峰温较高。

The branching structure of domestic and imported polyethylene of raised temperature resistance(PE-RT)pipe materials are studied by means of 13C-nuclear magnetic resonance(NMR),dynamic rheometer and differential scanning calorimeter(DSC).The results show that the melt flow rate and density of domestic and imported PE-RT pipe materials are similar,and the mechanical properties are close.The domestic materials are slightly more rigid,and the toughness is slightly lower,and the relative molecular mass is slightly lower,and the relative molecular mass distribution is slightly wider.The content of copolymerization monomer of domestic PE-RT pipe material is lower than that of import material,and the average length of ethylene sequence is slightly higher than that of import material,and the average length of butene sequence is slightly lower than that of import material,resulting in lower activation energy of viscous fluid flow than that of import material.The temperature melting peak of domestic materials is slightly higher than that of imported materials.