导　　师： 陈中华;刘安华

学科专业： 080502

授予学位： 博士

作　　者： ;

机构地区： 华南理工大学

摘　　要： 橡胶材料因其具有高弹性、耐磨性、绝缘性、质轻和加工方便等优点，被广泛用于交通、机械、电子、国防和国民经济的其它领域。随着社会进步和科学技术的发展，人们对橡胶各项性能指标的要求也越来越高。在已有材料基础上，经过适当处理来提升橡胶的各项性能指标是较为合理的方法之一。基于此思想，本论文主要从两方面开展了研究工作。 一是针对天然橡胶用补强填料炭黑与白炭黑的表面能高，与橡胶的相容性差，在混炼过程中很难均匀分散于橡胶基体中，从而导致填料对天然橡胶的补强作用有限的问题，采用表面接枝对炭黑与白炭黑进行表面改性处理，改善其在橡胶基体中的分散及与橡胶基体的相容性。研究了接枝改性前后的补强填料对橡胶材料整体性能的影响，主要分三个部分进行了研究。 /(1/)炭黑表面改性及其在天然橡胶中的补强效应研究。针对炭黑表面含氧官能团少，直接进行表面改性效果较差的问题，通过液相氧化增加炭黑表面含氧官能团后，再与聚乙二醇400进行接枝反应，并研究了不同条件对炭黑表面接枝改性的影响。在炭黑表面引入长链有机基团，从而降低了炭黑表面内聚能，增加了炭黑表面空间位阻。将接枝改性炭黑应用于补强天然橡胶，并与未改性炭黑进行比较的结果表明：接枝改性炭黑加入有利于提升天然橡胶的综合性能。 /(2/)白炭黑表面改性及其在天然橡胶中的补强效应研究。针对白炭黑表面硅羟基较多，改性反应较易进行的特点，通过在混炼阶段直接加入改性剂对白炭黑进行固相原位接枝改性，研究了不同改性条件对白炭黑原位接枝改性的影响。将原位接枝改性白炭黑应用于补强天然橡胶，并与未改性白炭黑进行比较的结果表明：原位接枝改性白炭黑加入有利于提升天然橡胶的综合性能。针对改性的影响条件较多的问题，对各种改性条件进行了正交试验，极差分析的结果与单因素分析结果一致。最佳改性条件为：改性剂选用Si-69，最佳用量为8份，分散剂B-52用量为2份，热处理温度为120℃，热处理时间为8min。 /(3/)对炭黑、白炭黑填充天然橡胶进行了应变软化和Payne效应研究。研究了炭黑、白炭黑补强天然橡胶的应变软化和补强机理。结果表明：在低填料填充量时，应变软化机理主要为分子链脱落与滑移；而在高填料填充量时，应变软化机理中聚集体破裂机理开始占主要因素。 二是针对炭黑改性虽对天然橡胶的强度、耐磨性等性能提升较大，但对天然橡胶的屈挠性能提升不够；白炭黑改性虽对天然橡胶的屈挠性能提升较大，但对天然橡胶的补强较弱的问题，通过在天然橡胶中并用部分反式天然橡胶、炭黑与白炭黑并用填充等手段来提升胶料的综合性能。研究了不同TPI并用量、不同硫化条件和不同炭黑与白炭黑并用比对胶料综合性能的影响。并将综合性能较好的配方用于弹性球铰的制备，研究了填料原位接枝改性、TPI与NR并用等方法对胶料应用性能的影响。研究结果表明：填充原位接枝改性的炭黑与白炭黑并用，天然橡胶中并用10份TPI的橡胶球铰径向静刚度、轴向静刚度和疲劳寿命都得到了提升。 Rubber materials were widely used in transportation, machinery, electronics, defense andother fields of national economic because of its high flexibility, abrasion resistance, insulation,light quality and easy to process, etc. With the progress in civilization and the development ontechnology, the requirements to rubber performance were increasing. It was a more reasonableapproach to improve rubber performance by appropriate treatment of the existing material.Based on this ideal, the research work was carried out in two major areas. Firstly, carbon black and silica were the main reinforcing filler used in natural rubber.They possessed high surface energy and poor coMPatibility with rubber, so they were difficultto disperse in rubber matrix uniformly in mixing process. These characteristics resulted in alimited reinforcement effect when they were mixed with natural rubber in order to improvethe dispersibility and coMPatibility. In situ grafting was selected for surface modification ofcarbon black and silica The effect of filler, which before and after in situ grafting, on theoverall reinforcing performance of rubber was studied. The study was divided into three parts: /(1/) Study on surface modification of carbon black and reinforcing effects of modifiedcarbon black in natural rubber. The content of oxygen-containing functional groups on carbonblack is low, the effect of direct surface modification of carbon black is poor. For this problem,liquid-phase oxidation was adopted to increase the oxygen-containing functional groups oncarbon black, and then carbon black with oxygen-containing functional groups was reactedwith Polyethylene glycol400in order to introduce the long-chain organic groups on thesurface of carbon black, thus reduce the surface energy and increases steric hindrance ofcarbon black. The effects of different conditions on the surface graft modification of carbonblack were studied. In-situ graft-modified carbon black was applied to reinforce natural rubber.The reinforcing efficiency of carbon black and in-situ graft-modified carbon black werecoMPared. The results showed that: in situ grafted carbon black was conducive to enhancingthe overall performance of natural rubber. In addition, the mechanism of performanceimprovement of rubber was studied. /(2/) Study on surface modification of silica and reinforcing effects of modification silica filled in natural rubber. The surface silanols of silica was more, it was much easier to carryout the modification reaction. For this feature, solid phase in situ grafting was used as thesilica surface modification method by adding modifying agent during mixing process. Theeffects of different conditions on the situ graft modification of silica were studied. In-situgraft-modified silica was applied to reinforce natural rubber. The reinforcing properties ofsilica and in-situ graft-modified silica were coMPared. The results showed that: in situ graftedsilica was conducive to enhancing the overall performance of natural rubber. Orthogonal testwas used to analyze the iMPact of various modification conditions on performance. Theresults of variance analysis and univariate analysis were consistent. The best modifiedconditions were as follows: the optimum modifier was Si-69, and the optimum dosage was8phr. The dosage of dispersing agent B-52was2phr. The heat treatment temperature was120℃. The heat treatment time was8min. /(3/) Study on strain softening effect and Payne effect of carbon black, silica-filled naturalrubber were studied. Strain softening and filler reinforcement mechanism of natural rubberwere analyzed. The resulus showed that molecular chain shedding and slip was the mainmechanism of strain softening at low filler loading, but aggregate rupture was the mainmechanism of strain softening at high filler loading. Secondly, grafted carbon black was used for enhancing the strength, abrasion resistanceand the other performance of natural rubber, but was not used for enhancing the flexproperties; silica grafted was used for enhancing the flex properties, but was not used forenhancing the strength of natural rubber. For this problem, the means of natural rubber blendwith trans-natural rubber, carbon black blend with silica were used to improve the overallperformance of rubber.The effects of different trans-natural rubber contents, different curingconditions and different proportions of carbon black and silica on the overall performance ofrubber were studied. Elastic ball joints were prepared according the formula having greatoverall performance, and application performances of elastic ball joints were studied. Theresults showed that the radial static stiffness, axial static stiffness and fatigue of elastic balljoint had been improved by filling in situ graft modified carbon black and silica as filler, at the same time adding10phr of TPI in natural rubber.

关 键 词： 炭黑 白炭黑 天然橡胶 接枝改性 补强机理 反式天然橡胶 弹性球铰

分 类 号： [TQ332]

领　　域： [化学工程]