【摘要】 热膨胀聚合物微球（TEPMs）可用于聚氨酯（PU）发泡，其特性直接影响PU泡沫的泡孔结构和性能。本工作选取偏氯乙烯（VDC）、丙烯腈（AN）、甲基丙烯酸甲酯（MMA）为单体，以异戊烷为发泡剂、纳米二氧化硅分散液为分散剂、乙二醇二甲基丙烯酸酯（EGDMA）为交联剂，通过悬浮聚合法，制备了以偏氯乙烯-丙烯腈-甲基丙烯酸甲酯（VDC-AN-MMA）共聚物为壳层、异戊烷为核的TEPMs。研究了纳米二氧化硅分散剂和EGDMA交联剂用量对TEPMs特性的影响，并通过分析不同交联度壳层聚合物的黏弹性变化，揭示了交联剂用量对TEPMs膨胀行为的作用机理。发现当分散剂用量为7.5%、交联剂用量为0.1%时，可获得发泡性能优异的微球（C-7.5-0.1）。进一步以C-7.5-0.1为PU发泡剂，研究了其添加量对PU泡沫泡孔结构和性能的影响。结果表明，当C-7.5-0.1添加量为8.0%时，所得PU泡沫的泡孔均匀、平均泡孔直径与微球在空气中膨胀后的尺寸相当，且孔隙率高、硬度低、力学性能好，在芯片化学机械研磨加工领域具有应用潜力。更多还原

【Abstract】 Thermally expandable polymer microspheres(TEPMs) can be utilized for polyurethane(PU) foaming, and their characteristics directly influence the pore structure and performance of PU foam. In this work, vinylidene chloride(VDC), acrylonitrile(AN), and methyl methacrylate(MMA) were selected as monomers, isopentane as the blowing agent, nano-silica dispersion as the dispersant, and ethylene glycol dimethacrylate(EGDMA) as the crosslinking agent. TEPMs with a VDC-AN-MMA copolymer shell and an isopentane core were prepared via suspension polymerization. The effects of nano-silica dispersant and EGDMA crosslinking agent usage on the properties of TEPMs were investigated. By analyzing the viscoelastic characteristics of shell polymers with different crosslinking degrees, the mechanism of crosslinking agent dosage on the expansion behavior of TEPMs was elucidated. It was found that when the dispersant usage was 7.5% and the crosslinking agent usage was 0.1%, microspheres(denoted as C-7.5-0.1) with excellent foaming performance could be obtained. Furthermore, using C-7.5-0.1 as the PU foaming agent, the influence of its addition amount on the pore structure and properties of PU foam was studied. The results indicated that when the addition amount of C-7.5-0.1 was 8.0%, the resulting PU foam exhibited uniform pores, an average pore diameter comparable to the size of the microspheres after expansion in air, high porosity, low hardness, and good mechanical properties, demonstrating potential for application in the field of chemical mechanical polishing for chip processing.更多还原