聚乙烯增韧改性研究

Study on toughening modification of polyethylene

聚乙烯(PE)作为五大合成树脂之一,也是我国产能最大,进口量最多的和合成树脂。凭借其良好的加工性能,力学性能,耐化学腐蚀性能,耐低温性能,并且具有来源广,价格低等优势,在薄膜,包装,管材,片材,纤维等领域得到了广泛的应用。正是因为聚乙烯树脂的耐化学腐蚀性好,耐低温,不透水,价格低廉的优点,使其在建筑物防水材料上有了很大的应用前景。但聚乙烯种类较多,不同种类的聚乙烯性能和价格差别大,单一种类的聚乙烯很难满足建筑防水材料的性能要求。通过PE/POE、PE/EVA共混改性,改善聚乙烯材料的韧性,强度,黏结性,低温弯折性等性能,达到建筑用防水片材的国家标准并且使产品具有一定的经济效益是本次研究的主要目的。讨论了HDPE/LLDPE/POE和HDPE/LLDPE/EVA共混改性体系中不同牌号聚乙烯的配比以及POE(或EVA)混合比例对共混材料各项性能的影响。通过对共混改性之后材料拉伸性能,撕裂强度,不透水性,低温弯折性,热空气老化,碱溶液老化等性能测试。发现原料配比与性能之间的关系,进而筛选出各项指标都达到甚至超过国家标准的产品配方,初步取得了不错的效果。

Polyethylene（PE）, as one of the top five synthetic resins, is also China’s largest synthetic resin with the largest production capacity and the largest import volume. With its good processing performance, mechanical properties, chemical corrosion resistance, low temperature resistance, and the advantages of wide source and low price, it has been widely used in the fields of film, packaging, pipe, sheet, fiber and so on. Because of its good chemical corrosion resistance, low temperature resistance, water permeability and low price, it has a great application prospect in building waterproof materials. However, there are many kinds of polyethylene, and the performance and price of polyethylene of different kinds are quite different. Single polyethylene is difficult to meet the performance requirements of building waterproof materials. The main purpose of this study is to improve the toughness, strength, cohesiveness and low temperature flexural properties of polyethylene by blending modification of PE/POE and PE/EVA, so as to achieve the national standard of waterproof sheet for construction and make the product have certain economic benefits. In this paper, the effects of the ratio of different grades of polyethylene in the blending modification system of HDPE/LLDPE/POE and HDPE/LLDPE/EVA and the influence of the mixing ratio of POE（or EVA） on the properties of the blends were discussed. The tensile properties, tear strength, watertightness, low temperature bending, hot air aging, alkali solution aging and other properties of the materials after blending modification were tested, to find out the relationship between material ratio and performance. Furthermore, the product formula with all indexes reaching or even exceeding the national standard has been screened out and achieved good results initially.