聚乙烯醇吹膜加工性能研究

Study on Processability of PVA Blown Film

研究了聚乙烯醇 (PVA)吹膜加工性能。经两种不同的增塑剂复配增塑后 ,可明显改善其加工流动性 ,当复合增塑剂用量为 2 5phr以上 ,PVA可以被较好地增塑 ,熔融塑化温度趋于定值。热性能研究表明 ,PVA为不完全结晶 ,其熔融曲线呈不规则分布。从PVA的流变性能可知 ,PVA熔体呈非牛顿性流体 ,剪切粘度随剪切速率增加而下降 ,并且醇解度较高的树脂 ,剪切粘度也较高。不同醇解度的PVA树脂 ,均能通过增塑改性后熔融挤出加工吹塑成膜。高醇解度PVA膜的水溶解温度高 ,而低醇解度PVA膜具有低温快速水解的性能。

The processability of PVA blown film was studied Modified by means of the recombination of two different kinds of plasticizing agent,the processability of the film could be improved apparently When the content of the recombined plasticizing agent was more than 25 phr,PVA could be plastified satisfactorily,and the melting temperature tended to be steady The study on the thermal behavior of the film showed that the crystallization of PVA was incompletely,and the distribution of its melting curve was irregular The results of rheological test of the film showed that the melt of PVA was non Newtonian fluid and the shearing viscosity decreased with the increase of shearing rate, and when the alcoholysis degree of PVA was higher,the shearing viscosity of the resin could also be higher PVA resins with different alcoholysis degree could all be used to prepare blown film by extrusion after plasticization modification The film of high alcoholysis degree PVA could only be melted in high temperature water and that of low alcoholysis degree PVA could be melted quickly in low temperature water