This paper reviews the advantages and disadvantages of various methods to improve the surface glossiness of polypropylene (PP) which include adding polyethylene wax,high gloss barium sulfate,nucleating agent,and inorganic particles as well as adjusting operating conditions.It focuses on the roles of nucleating agents in enhancing glossiness and transparency of PP.The paper describes the types of nucleating agents and contribution to the glossiness and transparency of PP.Several agents whose grades and properties are outlined,among which,dibenzylidene sorbitol nucleating agents have multiple grades,HPN-20E along with other agents improve the glossiness of PP significantly.The mechanisms of nucleating agents are analyzed,which involve the transition of PP spiral structure by nucleating agents,epitaxial crystallization,and PP-containing V structure formed by hydrogen-bonded dimers in nucleating agents.Furthermore,the applications of gloss and transparent PP in automotive decorations and small household electrical appliance shell are demonstrated.The development and future trend of enhanced gloss and transparent PP are proposed.%综述了通过添加聚乙烯蜡、高光硫酸钡、无机粒子、成核剂及调整注塑工艺条件等增加聚丙烯(PP)表面光泽度方法的优缺点,着重介绍了成核剂对PP的增光增透作用.列举了成核剂的种类及其对PP光泽度与透明性的影响,并重点介绍了几种国内外增光增透成核剂的牌号、性质,发现二苄叉山梨醇类成核剂的牌号较多,且HPN-20E对PP增光效果提高显著,其他成核剂的增光效果也较显著.简要分析了成核剂的作用机理,包括成核剂转变PP螺旋结构的作用机理、“附生”结晶理论,以及成核剂分子氢键二聚形成V形结构容纳PP的成核作用.此外,还阐述了其在汽车内外饰及小家电外壳等领域的应用.最后,对增光增透PP的发展进行了总结与前景展望.
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