【作者】 杨洁；

【导师】 高延敏；

【作者基本信息】 江苏科技大学 ， 材料学， 2011， 硕士

【摘要】 聚乙烯作为世界上生产量最大、种类繁多的最重要的合成树脂之一,其应用早已深入人们的日常生活。虽然其自身具有许多优点,但也存在着性能方面的某些弱点,这限制了它的应用市场。本课题选用纳米碳酸钙填充改性的方法对高密度聚乙烯进行力学性能方面的改性,首先是针对纳米碳酸钙表面团聚以及与基体树脂结合性差的问题,选择了偶联剂对纳米粒子进行了相关改性实验,并研究了经表面处理过的纳米二氧化硅/纳米碳酸钙二元协同改性HDPE的性能;然后本课题从高分子包覆改性纳米碳酸钙的的角度,采用苯乙烯原位聚合改性纳米碳酸钙,并研究了其反应所得的复合粒子与HDPE进行反应性共混对HDPE性能的影响。针对上述问题取得以下结论:⑴利用FT-IR、SEM、XRD、TG分析等对改性前后纳米CaCO₃的表面形貌、分散情况进行了分析比较。结果表明,相较于硅烷偶联剂KH-151和KH570,钛酸酯偶联剂KH101改性效果最好。并得出最佳改性条件为:偶联剂用量为纳米CaCO₃的3wt.%,环己酮用量为纳米CaCO₃质量的5倍,反应温度为80℃,反应时间为60min。⑵单独使用经偶联剂表面处理过的纳米碳酸钙和纳米二氧化硅对HDPE进行填充改性:①纳米CaCO₃,填充量为20%²5%冲击强度有最大值,含量在10%-20%拉伸强度有最大值。②纳米SiO₂,填充量为6%⁸%之间拉伸和冲击强度有最大值。⑶二元填充改性,纳米CaCO₃:纳米SiO₂:HDPE=25:7:100质量比的体系比单独纳米CaCO₃纳米SiO₂各自单独填充HDPE拉伸和冲击强度的最大值没下降多少,同时提高了拉伸、冲击两种力学性能,达到了预期填充改性效果。⑷苯乙烯原位聚合改性纳米碳酸钙得到PS-nanoCaCO₃复合粒子,选用丙烯酸对纳米碳酸钙表面预处理,通过对比实验得出最佳反应条件为:反应时间为8小时,引发剂过硫酸钾用量为单体量的1%,乳化剂十二烷基苯磺酸钠的用量为单体量的3%,加入经丙烯酸改性的的纳米碳酸钙的量为单体量的25%。⑸PS-nanoCaCO₃和HDPE的反应性共混,通过实验可知同时加入引发剂DCP和多官能团物质TMPTA,能够使得共混体系有较为良好的相容性。尝试了加入不同比例的TMPTA对共混体系反应性的影响,随着TMPTA量的增加,共混体系的相容性有所改善,但是变化到2.0%相较于1.0%不是非常的明显,本实验选取添加量为1.0%。⑹对比了共混物不同比例所得产物的相容性,并研究了产物的力学性能,得出PS-nanoCaCO₃添加量为10份时,共混改性效果最佳,平衡扭矩最大,力学性能最优,其中拉伸强度提高14.2%,冲击强度提高了15.2%。80/20的力学强度相对也有所提高,随着PS-nanoCaCO₃比例的继续提高,力学性能成下降趋势。更多还原

【Abstract】 Polyethylene as the world’s largest, with wide variety of productions is one of the most important synthetic resin, its application already goes deep into people’s daily life. Although it has many advantages, but there is also some of the weaknesses properties which limited its application market.This topic use nano CaCO₃ filling modification to modify high density polyethylene to improve its mechanical properties .First coupling agent has been chose to solve the problem of reunited and poor matrix combination. Study has been taken on the modification experiments by surface processed nano-silica/nano CaCO₃ dual cooperative modified HDPE performance. Then research has been done from the Angle of nanometer calcium carbonate, using in situ polymerization of styrene modification, and the nano CaCO₃ composite particle from the reaction with HDPE reacted to the HDPE sexual blend properties. In view of the above questions made the following conclusions:（1）The surface morphology and dispersing condition of nano CaCO₃ are analyzed and compared by the analysis of FT-IR, SEM, XRD and TG.Results show that , compared with silane coupling agent KH 151 and KH570, titanate coupling agent KH101 modified the best effect. And we find optimum conditions of titanium coupling agent modification: nano CaCO₃ content 3wt%, the content of cyclohexanone is five times of nano CaCO₃, the reaction temperature is q 80℃, stirring time is 60min.（2）Use nano CaCO₃ and nano-silica separately to modify HDPE:①nano CaCO₃: For filling quantity 20% 25% impact strength has maximum, content in 10%-20% tensile strength have maximum.②nano-silica: For filling quantity between 6% to 8% tensile and impact strength have maximum（3）Binary filling modification, the mass ratio of the system is Nano CaCO₃: nano SiO₂: HDPE =25:7:100,compared with HDPE separately filled with nano CaCO₃ or nano SiO₂, its impact strength and tensile has improved and not drop many from the maximum, the performance is good.（4）In situ polymerization of styrene modification of nano CaCO₃ get PS - nano CaCO₃ composite particle, choose acrylic for nano CaCO₃ surface pretreatment, through the contrast experiments obtain the best reaction conditions: the reaction time is eight hours, the content of initiator of potassium peroxydisulfate is 1% of the monomer, emulsifier dodecylbenzenesulfonic acid sodium consumption is 3% of the monomer, the dosage of modified nano CaCO₃ is 25% of monomer quantity.（5）It is indicated that in reactive blend of PS- nanoCaCO₃ and HDPE, the addition of DCP and TMPTA can improve the compatibility. Tried to add different proportions of TMPTA in blend system , results show that with the increased of TMPTA, blending systems compatibility improved, but changes from 1.0% to 2.0% is not very obvious, in this experiment the additives is 1.0%（6）Compare the compatibility and mechanical property of the blend wit different proportion of raw material, Contrast of the products, and the compatibility of the mechanical properties of the product research, when the dosage of PS - nanoCaCO₃ is 10 percent, blending modified effects is best, balance torque get maximum and has the best mechanical properties. tensile strength increased 14.2% and the impact strength increased 15.2 percent. Mechanics intensity of 80/20 reaction system is also been improved, with improvement of PS-nanoCaCO₃ the mechanical property continue decline.更多还原