【摘要】 研究了以碱为催化剂,使乙烯—醋酸乙烯共聚物(EVA)经一次醇解直接制备高醇解度乙烯—乙烯醇共聚物(EVOH)的方法,主要研究了不同醇解条件对EVOH醇解度的影响以及醇解度对树脂分子量分布、熔点和熔体指数的影响。结果表明,通过不断地将醇解副产物排出反应体系,可以在较低的碱浓度下经一次醇解过程,直接得到醇解度高于99.5%的EVOH树脂;醇解度对EVOH分子量分布的影响很小;醇解度增加,树脂的熔点上升,熔体指数增大。更多还原

【Abstract】 The direct preparation of EVOH resin by one-step alcoholysis process of EVA resin with alkali as catalyst was studied in this paper, with stress on the influence of alcoholysis condition on the alcoholysis degree of EVOH resin. The effect of alcoholysis degree of EVOH resin on it’s molecular weight and molecular weight distribution, melting point and melt index was also studied. The results showed that EVOH resin with alcoholysis degree higher than 99.5% could be prepared directly by one—step alcoholysis process at low alkali concentration ,in which the by—product methylacetate was removed from the alcoholysis system continuously. The melting point of EVOH resin increased with the increase of the alcoholysis degree. The influence of alcoholysis degree of EVOH resin on its molecular weight distribution was very small.更多还原