【作者】 王海平；

【导师】 朱新生； 任俊；

【作者基本信息】 苏州大学 ， 材料工程， 2012， 硕士

【摘要】 随着科技的进步和社会的发展，人们对材料的要求越来越高且多样化。人们希望材料既耐高温又易于成型加工；既有较高的韧性又有较大的刚度；既有较好的持久性又价格低廉。因此，改性已成为研制高性能聚合物材料的一个重要途径。本文系统研究了茂金属聚乙烯对复合聚乙烯薄膜的微观结构及其物理力学性能影响，探讨了在聚乙烯吹膜过程中添加抗静电剂和色母料后薄膜性能的变化，还探讨了聚丙烯对聚乙烯复合片材刚性和低温抗冲击性能的影响，重点揭示了不同类型茂金属聚乙烯对薄膜的改性作用和机理。并得出如下主要结论：1）茂金属聚乙烯明显增大了聚乙烯薄膜的摩擦系数，当其添加量在10%-20%时即可达到较好效果。2）茂金属聚乙烯降低了薄膜的起封温度和起始热封强度。在茂金属聚乙烯添加量为15%左右时，薄膜雾度值为5%-8%。另外，茂金属聚乙烯提高了薄膜的抗冲击性能和拉伸性能。3）当茂金属聚乙烯微观结构与聚乙烯薄膜基础原料相似时，其改性效果较差。4）添加一定量白色母粒后，聚乙烯薄膜纵横向刚性均有所下降，但韧性增加。薄膜的纵向刚性高于横向刚性的原因在于：聚乙烯大分子链在薄膜加工方向上的排列更为规整，结晶度更高。5）色母料导致薄膜光泽度少许增加。当白色母添加量控制在6-8%时，薄膜的不透度和光泽度均能保持在80%左右。6）抗静电剂明显降低了薄膜表面电阻值。当抗静电剂添加量小于4%时，所有改性薄膜的表面电阻值在最初的一个月以内均呈较快下降趋势，但在一个月以后表面电阻值均逐渐趋于平稳。当抗静电剂添加量不超过4%时，薄膜的爽滑性和透明性保持不变,但热封强度略有下降。7）在复合片材结构、加工工艺等参数不变的情况下，当EAA含量从7%提升至9%时，铝箔和粘结树脂之间剥离强度的平均值从5-6N/m提升至8-9N/m。8）在多层共挤复合片材中，添加一定量聚丙烯后，复合片材的刚性略有提高，其中，片材横向刚性的提升高于纵向刚性。本论文的特色在于：基于实际生产条件，系统地进行了多种聚乙烯薄膜和复合片材共混功能化改性研究，特别是借用X射线衍射和差热量热法分析手段，详细研究了聚乙烯原料及其共混改性膜结晶性与微观结构，这为聚乙烯复合膜开发研究提供示范作用。更多还原

【Abstract】 With the development of society and technology, the polymeric materials and theirgoods are always expected to have high-temperature resistance, high stiffness, goodflexibility, easy processing and cheapness. Thus the physical and chemical modifications ofpolymeric materials are usually become important ready development techniques. Theeffects of metallocene polyethylene, antistatic agents, functional master-batch on the heatsealability, the friction coefficient, transparency, the impact resistance, and tensileproperties of polyethylene blown films were carefully investigated in detail in this thesis.In addition, the isotactic polypropylene and ethylene-acrylic acid copolymer were used toimprove the rigidity and the binding of composite sheets respectively. The main findingsare as follows:(1)Metallocene polyethylene remarkably increases the friction coefficients and theinitial seal strength and decreases the initial seal temperature of blending polyethylenefilms, and also improves the impact resistance and tensile strength of the films. The hazevalues of the films are reduced when the metallocene polyethylene is at the dosages of15%. However, many of desirable properties can not be realized if the microstructure ofmetallocene polyethylene is more or less similar to that of polyethylene in the basic blownfilm formulation.(2) Although the white master batch unexpectedly diminishes both longitudinal andlatitudinal rigidities of blown polyethylene films, the impact toughness of the films wouldbe gained as much. The macromolecular orientation along the production line can accountfor the greater rigidity of the films in the longitudinal direction than in the latitudinaldirection. The white master batch leads to the reduced stiffness and the increased gloss ofthe blown polyethylene films to a less extent. Both the transparency and the gloss of thefilms can maintain at ca.80%if the dosing level of master batch is6-8%.(3) The antistatic agents lower significantly the surface electric resistance andreluctantly the heat seal strength, but do not cause obvious changes in the transparency and smoothness of the blown polyethylene films at the concentrations of0-4%.(4) While the composite sheet structure and processing parameters are kept same,the average peel strengths of the penta-layer composite sheet-polyethylene/EAA/aluminum/EAA/polyethylene are increased from5-6N/m to8-9N/m,corresponding to the increases of EAA from7%to9%.(5) In the multi-layer co-extruded composite molding sheet, the additive isotacticpolypropylene causes the slightly enhanced rigidity, a bit higher in the latitude than inlongitude, and the unfortunately declined impact toughness at low temperatures.The main feature of the thesis work is that, the blending modifications of several kindsof high performance polyethylene films and composite sheets were carried out based onthe realistic production conditions. The crystallinity and microstructure of manypolyethylene raw materials and compounding films were investigated with X-raysdiffraction and differential scan calorimetry in detail, and this can act as the exemplareffect for the research and development of high performance polyolefin films and sheets.更多还原