【作者】 姚瑜；

【导师】 张军；

【作者基本信息】 南京工业大学 ， 材料学， 2005， 硕士

【摘要】 聚丙烯(PP)作为通用塑料，以产量大、应用面广以及物美价廉而著称，但聚丙烯具有非极性和结晶性，其与极性聚合物、无机填料及增强材料等相容性差，其染色性、粘接性、抗静电性、亲水性也较差，这些缺点制约了聚丙烯的进一步推广应用。本文利用聚丙烯固相接枝丙烯酸(AA)、聚丙烯与乙烯-丙烯酸共聚物(EAA)共混和聚丙烯中空纤维膜的表面活性剂浸渍处理，三个途径分别对聚丙烯进行亲水改性研究。 通过接枝共聚，在聚丙烯大分子上引入适当的极性基团或支链是聚丙烯亲水改性的一种简单而又行之有效的方法。与传统的聚合方法相比，固相接枝共聚法具有高效节能等优点，目前被广泛地研究与应用。实验采用亲水性的AA作为接枝单体，探讨了反应时间、反应温度、单体用量及引发剂用量等因素对固相接枝反应的影响。通过FTIR证实AA确已接枝到PP链上形成PP-g-AA接枝物，并采用水接触角方法表征了接枝物的亲水性能。实验结果表明，当反应温度为120℃，反应时间为90min，PP：AA：BPO=100：10：0.4(质量比)时，可获得AA最大接枝率1.31％，与未接枝的聚丙烯相比，接枝物水接触角由90°减小到81.3°，亲水性能得到明显改善。DSC结果表明，固相接枝物PP-g-AA的熔融温度T_m和结晶温度T_c略有下降，结晶焓△H_c、熔融焓△H_m略有上升，结晶速率加快，结晶度有所提高；接枝改性提高了PP的热稳定性。 与普通固相接枝法相比，双单体固相共聚接枝改性PP是一种得到高极性PP的有效方法，加入适当比例的第二单体(或称为共聚单体)，可以大大提高接枝单体在PP上的接枝率，同时可以有效抑制在普通固相接枝过程中PP的严重降解，得到性能较好的高极性PP。实验研究了以苯乙烯(St)为共单体，PP固相接枝AA的反应工艺，探讨了反应时间、反应温度、共单体用量及引发剂用量等因素对接枝反应的影响。通过FTIR证实AA和St确实接枝到PP链上形成PP-g-(St-AA)接枝物，并采用水接触角方法表征了接枝物的亲水性能。实验结果表明，当反应温度为120℃，反应时间为90min，PP：AA：St：BPO=100：10：2：0.4(质量比)时，可获得AA最大接枝率4.46％，与相同实验条件下，未加入St的PP固相接枝AA体系相比，接枝物接枝率提高了3.15％，水接触角由更多还原

【Abstract】 Polypropylene (PP) is one of the most commonly used plastics because of its versatile properties, wild applicability, and low cost. However, PP is limited in its further application due to its non-polarity and crystallizability, poor compatibility with synthetic polar polymers, inorganic fillers and enhanced materials, poor dyeability, adhesivity, antistatic property, and hydrophilicity. In this paper, PP was hydrophilic modified by three means: solid phase grafting with acrylic acid (AA), blending with ethylene-acrylic acid copolymer (EAA), and impregnating into surfactant, separately.Graft copolymerization to introduce appropriate polar group or chain onto PP backbone is a simple and effective approach of hydrophilic modification. Compared with other grafting methods, solid phase grafting is such a high efficient and energy conserving method that it is studied and applied wildly at the present time. In this study, solid phase grafting technology for AA onto PP was investigated in details, and the effects of factors, including reaction time, reaction temperature, as well as concentration of monomer and initiator, on grafting reaction were also studied. It was proved by Fourier transform infrared spectroscopy (FTIR) that AA was actually grafted onto the PP backbone. Contact angle of water was measured to characterize the hydrophilicity of grafted PP. The results showed that the maximum graft degree was achieved as 1.31% when the reaction was operated under 120℃, for 90min with PP:AA:BPO=100:10:0.4(mass ratio). The contact angle of the grafted PP decreased from 90°(original PP) to 81.3°, indicating the improvement of hydrophilicity. It was found by differential scanning calorimeter (DSC) that, PP solid phase grafting AA copolymer (PP-g-AA) possessed lower melting and crystallization temperatures, higher melting and crystallization enthalpy, larger crystallization rate as well as crystallinity than the original PP. The results of thermogravimetric analyses (TGA) indicated that graft modification could enhance the thermal stability of the material.更多还原