【作者】 宋波；

【导师】 黄锐；

【作者基本信息】 四川大学 ， 材料加工工程， 2004， 博士

【摘要】 本论文围绕高性能、应用研究和理论研究三个方面,对弹性体及无机刚性粒子增韧增强PA6复合材料的形态结构与性能的关系进行了较为系统和深入的研究,获得了一些有价值的发现。在大量实验数据的基础上,总结得出了一些规律性结果,并首次提出了“球形粒子滚动”(滚珠)增韧机理模型。开发了一些有价值的新产品,并且在工业上得到了初步应用,取得了较好社会和经济效益。这些工作主要包括:1、研究了POE弹性体粒径大小PA6/POE共混力学性能的影响。结果表明:弹性体分散相粒径的大小与分布是影响共混物韧性的主要因素,弹性体分散相粒径小于0.2μm时,对PA6增韧效果不佳。但弹性体粒径大小和分布并不影响共混物的屈服强度和模量。例如,加入75%PA6/25%POE缺口冲击强度比PA6提高不到一倍。对于弹性体粒径的大部分在0.2μm以下,最小的小于50nm的80%PA6/20%POE-g-MAH,其缺口冲击强度仅比PA6提高了三倍多点。而弹性体粒子在0.2~0.5μm 间的80%PA6/13%POE/7% POE-g-MAH缺口冲击强度比PA6提高了近八倍。2、以马来酸酐接枝的乙烯和辛烯共聚热塑性弹性体增韧尼龙6/蒙脱土纳米复合材料(NCH),结果表明:在POE-g-MAH含量在8~10%间, NCH/POE-g-MAH复合材料发生脆韧转变。当POE-g-MAH含量为16%时,NCH/POE-g-MAH的缺口冲击强度已<WP=4>大于80kJ/m2;当POE-g-MAH含量为20%时,NCH/POE-g-MAH的缺口冲击强度已接近120kJ/m2。NCH/POE-g-MAH复合材料的拉伸强度和弹性模量都是随POE-g-MAH的增加而线性下降。在相同的POE-g-MAH加入量时,NCH/POE-g-MAH略低于PA6/POE-g-MAH(约低4MPa左右),但NCH/ POE-g-MAH弹性模量高于PA6/POE-g-MAH。弹性体增韧NCH的最佳粒径下限低于PA6。3、研究了微米级CaC03(CC1)、纳米级CaC03(CC2)、普通CaC03(CC3)、或滑石粉(talc)作为刚性微粒,POE-g-MAH作为弹性微粒,首先将PA6/填料熔融共混,再将制得的复合材料与POE-g-MAH熔融共混制备得PA6/填料/POE-g-MAH复合材料的形态结构与性能。结果表明:对于PA6/CaC03/POE-g-MAH体系,部分碳酸钙为橡胶包覆形成橡胶包覆粒子的核-壳结构(硬核-软壳)分散体,部分碳酸钙单独分散在PA6基体中。弹性粒子的粒径尺寸也变大。以PA6/CaCO3为基料用POE-g-MAH增韧,PA6/CaCO3/POE-g-MAH产生脆韧转变所需的POE-g- MAH量比纯PA6多,且随碳酸钙的增加而增加,但碳酸钙的粒径大小对这种转变没有影响。CaCO3和POE-g-MAH对PA6有协同增韧作用,这种协同作用在脆韧转变之后表现相当明显,且随CaCO3的量的增大而越显著,微米级碳酸钙和普通碳酸钙的协同增韧作用优于纳米级碳酸钙。得到了PA6/微米级CaCO3/POE-g-MAH的屈服强度与弹性体和碳酸钙体积含量关系经验公式为。 得到PA6/纳米级CaCO3/POE-g-MAH的屈服强度与弹性体和碳酸钙体积含量关系经验公式为 。在含有滑石粉的复合材料中,填料粒子主要单独分散在PA6基体中。与未加填料的PA6/POE-g-MAH相比,而体系中的弹性体粒子要大一些。加入了滑石粉的PA6/talc/POE-g-MAH和PA6/talc/CaCO3/ POE-g-MAH,复合材料的缺口冲击强度显著下降。在组成重量比相同时,拉伸强度从大到小的顺序为PA6/talc/ <WP=5>POE-g-MAH> PA6/talc/CaCO3/POE-g-MAH> PA6/CaCO3/ POE-g-MAH。 研究结果表明,进入到弹性体中的填料不能提高复合材料弹性模量,只有分散于基体中的填料才能提高复合材料弹性模量。4、研究了纳米级CaC03、微米级CaC03、或滑石粉作为刚性微粒,POE-g-MAH作为弹性微粒,首先将POE-g-MAH与刚性微粒熔融共混制成母料,再将母料与PA6熔融共混制备得PA6/填料/POE-g-MAH复合材料的形态结构与性能。结果表明:含微米级碳酸钙的体系主要形成橡胶包覆单个粒子的核-壳结构(硬核-软壳)分散体。与未加填料的PA6/POE-g-MAH相比,弹性粒子的粒径尺寸变大。加纳米级碳酸钙的体系中纳米级碳酸钙成橡胶包覆团聚粒子的核-壳结构(硬核-软壳)分散体。对弹性体粒子的大小及分布的影响与微米级碳酸钙相似。加滑石粉的体系的填料粒子主要单独分散在PA6基体中。与未加填料的PA6/POE-g-MAH相比,不改变弹性粒子的大小及分布。从缺口冲击强度数据来看,随着POE-g-MAH包覆碳酸钙量的增加,脆韧转变后延。以POE-g-MAH包覆40%碳酸钙后对PA6的增韧效果最好,优于纯POE-g-MAH、包覆20%碳酸钙和60%碳酸钙的POE-g-MAH。PA6/POE-g-MAH/CC2复合材料中纳米碳酸钙或者其团聚体与弹性体形成的“沙袋”结构并不能消除团聚体对材料韧性的劣化作用,不利于韧性的提高。碳酸钙进入到弹性体后增加了弹性体体积,体现的是弹性体的性质。进入到弹性体中的填料不能提高复合材料弹性模量。5、以PA6/超细碳酸钙/POE-g-MAH(组成为80/20/13.3,重量比)为例,考察四种工艺:(1)塑料、橡胶、填料三元一起共混;(2)塑料先与填料共混、再与橡胶共混;(3)塑料先与橡胶共混、再与填料共混;(4)橡胶先与填料共混、再与塑料共混。对制备的复合材料的相分布、结晶行为及力学性能的影响。结果表明:工艺一的碳酸钙粒子既分散于基体PA6中,也分散于弹性体中。分散于基体中的碳酸钙粒子基本上是以单个粒子形式分散的,没有团聚;分散于弹性体中的碳酸钙粒子大部分是以团聚体形式分散的,也有少量是?更多还原

【Abstract】 Preparation of polymer composites is one of the important methods to realized high performance of polymer materials. In this paper, the relationship between the structure and properties of polyamide 6 (PA6) composite toughened by maleated ethylene-octene copolymer (POE-g-MAH) and inorganic filler together was studied systematically. Deep investigation and analysis on high performance, application and theory of polyamide 6 composites were carried out. A lot of valuable information was obtained that can be used for development of polyamide 6 composites. The main works and conclusions were listed as following: 1. The toughening of PA6 using ethylene-octene copolymer (POE) and a maleic anhydride (MAH) functionalized version (POE-g-MAH) was examined. Combinations of the POE and POE-g-MAH blends with PA6 give higher levels of toughening than is achieved with the functionalized elastomer alone. The particles of pure POE are too large for toughening PA6, whereas POE-g-MAH alone yielded particles are too small for optimal toughening. Combinations of the two types of elastomers gave continuously varying particle size between these extreme limits. This suggests that there is an optimal rubber particle size for PA6 to toughen, and the optimal size is about 0.2~1.0μm. But particle size did not affect the yield strength and modulus of blends.2. The toughening of PA6-clay nano-composites (NCH) using ethylene-octene copolymer (POE) and a maleic anhydride (MAH) <WP=8>functionalized version (POE-g-MAH) was examined. The functionalized elastomer alone or combinations of the POE and POE-g-MAH blends with NCH give the same much high levels of toughening, which is much higher than that of PA6. Combinations of the two types of elastomers also gave continuously varying particle size between these extreme limits. The lowest particle size for optimal toughening is smaller for NCH than PA6. 3. Micron CaCO3 (CC1), nanometer CaCO3 (CC2), general CaCO3 (CC3) and/or talc as inorganic fillers blending with PA6 by two-screw first, and then blending with POE-g-MAH elastomer to prepare PA6/inorganic filler/OE-g-MAH composites were studied. The results showed:For PA6/CaCO3/POE-g-MAH, parts of CaCO3 were coated by POE-g-MAH to form elastomer encapsulated single CaCO3 particle as soft shell-rigid core structure, parts of CaCO3 dispersed separately in PA matrix. The size of elastomer is larger than that of PA6/POE-g-MAH.The brittle-ductile transition of PA6/CaCO3/ POE-g-MAH moves to high POE-g-MAH content with the increase of PA6/CaCO3 ratio. The synergetic effect of CaCO3 and POE-g-MAH on toughening PA6 is very outstanding when ductile fracture. However, the tensile yield strength of PA6/CaCO3/ POE-g-MAH decreases a little with the increase of CaCO3 content. The empiristic formula of the tensile yield strength of PA6/CC1/ POE-g-MAH with volume contents of CC1 and POE-g-MAH is as And the empiristic formula of the tensile yield strength of PA6/CC2/ POE-g-MAH with volume contents of CC1 and POE-g-MAH is as Talc is only dispersed in PA6 matrix in PA6/talc/POE-g-MAH composites. The particle of elastomer is somewhat larger than of PA6/POE-g-MAH. The notched impact strength of PA6/talc/POE-g-MAH is much lower than that of PA6/CaCO3/ POE-g-MAH. <WP=9> With the same composition, the order of yield strength from high to low of composites are: PA6/talc/POE-g-MAH> PA6/talc/CaCO3/POE-g-MAH> PA6/CaCO3/ POE-g-MAH. The result also showed that inorganic filler could improve the modulus of PA6/ inorganic filler/POE-g-MAH composites only when they dispersed in PA6 matrix.4. Micron CaCO3 (CC1), nanometer CaCO3 (CC2), or talc blending with POE-g-MAH by two-screw first, and then blending with PA6 elastomer to prepare PA6/ POE-g-MAH/inorganic filler composites were studied. The results showed:CaCO3 single particles were coated by POE-g-MAH to form soft shell-rigid core structure in PA6/CC1/POE-g-MAH. The size of elastomer alone is larger than that of PA6/POE-g-MAH. CaCO3 particles agglomerate are embedded by POE-g-MAH to form “sandbag-like?更多还原