聚乙烯醇的共混改性

Blending modification of polyvinyl alcohol

将两种牌号聚乙烯醇(PVA)(PVA1799和PVA0599)混合,然后分别加入甘油/三甘醇、甘油/乙酰胺复合增塑剂对其进行改性。加入复合增塑剂使PVA1799/PVA0599的熔点、结晶度和热分解温度降低;与PVA1799/PVA0599体系相比,改性PVA1799/PVA0599的拉伸强度下降、拉伸断裂应变明显提高;随着PVA0599含量增加,改性PVA1799/PVA0599的熔体流动速率增大;m(PVA1799)/m(PVA0599)为3∶2时,随复合增塑剂用量增加,改性PVA1799/PVA0599的流动性变好;甘油/乙酰胺增塑效果优于甘油/三甘醇;改性PVA1799/PVA0599体系在复合增塑剂为30 phr时可望实现熔融加工。

The authors blended two grades of polyvinyl alcohol（PVA）,PVA1799 and PVA0599,and then added glycerin/triethylene glycol or glycerin/acetamide composite plasticizer with the aim of modifying PVA.The melting point,crystallinity and thermal decomposition temperature of the modified PVA1799/PVA0599 reduced with the addition of the composite plasticizers.The modified PVA1799/PVA0599 had decreased tensile strength but significantly increased tensile strain at break in comparison with the PVA1799/PVA0599 blend.The melt flow rate of the modified PVA1799/PVA0599 blend rose with increasing the content of PVA0599.The flowability of the modified PVA1799/PVA0599 became better with the increase in the composite plasticizer content when the mass ratio of PVA1799 to PVA0599 was 3∶2.Moreover,the plasticizing effect in glycerin/acetamide composite plasticizer was superior to that of glycerin/triethylene glycol composite plasticizer.When the content of the composite plasticizer is 30 phr,the modified PVA1799/PVA0599 blend seems to realize melt processing.