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旨在将纳米Al2O3分散在聚乙烯(PE)和乙烯醋酸乙烯共聚物(EVA)的共混物中,构建具有选择性分布结构的局域高粒子浓度导热复合材料。采用纳米Al2O3为导热填料,以PE和EVA为基体树脂,使用熔融共混法制备了Al2O3/PE-EVA导热复合材料。利用选择性溶液萃取方法和SEM研究了PE-EVA共混物的相结构及纳米Al2O3在共混物中的分布,评价了Al2O3/PE-EVA复合材料的导热性能与力学性能。结果表明:在PE与EVA质量比为1∶1时可获得具有两相共连续结构的共混物;在两相共连续PE-EVA共混物中引入纳米Al2O3后,发现纳米Al2O3主要分布在PE相中;纳米Al2O3的分布行为及共连续结构的形成有助于提高复合材料的导热性能,在纳米Al2O3质量分数为50%时,与Al2O3/PE复合材料相比,具有选择分布和相连续结构的Al2O3/PEEVA复合材料的热导率提高了21.2%;随着纳米Al2O3质量分数的增加,Al2O3/PE-EVA复合材料的拉伸强度与Al2O3/PE复合材料的拉伸强度相近,同时由于EVA相的增韧作用,其断裂伸长率优于Al2O3/PE复合材料。
The aim is to disperse nano-Al2O3 in the blend of polyethylene (PE) and ethylene-vinyl acetate copolymer (EVA) to form localized high particle concentration thermal conductive composites with selective distribution structure. Al2O3 / PE-EVA thermal conductive composites were prepared by melt blending method using nano-Al2O3 as thermal conductive filler, PE and EVA as matrix resin. The phase structure of PE-EVA blends and the distribution of nano-Al2O3 in the blends were studied by selective solution extraction and SEM. The thermal conductivity and mechanical properties of the composites were evaluated. The results showed that when the weight ratio of PE to EVA was 1: 1, the blends with two-phase co-continuous structure were obtained. After the nano-Al2O3 was introduced into the two-phase co-continuous PE-EVA blends, PE phase. The distribution behavior of nano-Al2O3 and the formation of co-continuous structure help to improve the thermal conductivity of the composites. Compared with Al2O3 / PE composites, nano-Al2O3 has a selective distribution and continuous phase The thermal conductivity of Al 2 O 3 / PEEVA composites increased by 21.2%. With the increase of mass fraction of nano-Al 2 O 3, the tensile strength of Al 2 O 3 / PE-EVA composites was similar to the tensile strength of Al 2 O 3 / PE composites. EVA toughening effect, its elongation at break is better than that of Al2O3 / PE composites.