聚合物改性碳纳米管及其对PVC增韧的研究

STUDY ON MODIFICATION OF CARBON NANOTUBES WITH POLYMERS AND TOUGHENING OF PVC WITH MODIFIED CARBON NANOTUBES

通过原子转移自由基聚合法合成了PMMA-Br、PBA-Br和PMMA-b-PBA-Br3种聚合物,采用叠氮法分别用它们修饰单壁碳纳米管(SWNT)。通过红外光谱、拉曼光谱、热失重法和透射电子显微镜综合分析了其修饰效果;并用经聚合物修饰的SWNT制备了PVC/SWNT纳米复合材料。结果表明,在100gPVC中加入0.1g经聚合物修饰的SWNT后,纳米复合材料的力学性能明显提高,其中PVC/PMMA-b-PBA-SWNT纳米复合材料的冲击强度是纯PVC的4倍;PVC/PMMA-SWNT纳米复合材料的冲击强度是纯PVC的3.2倍,断裂伸长率提高了2.5倍,拉伸强度提高了16%,弯曲强度提高了18%;PVC/PBA-SWNT纳米复合材料的拉伸强度和断裂伸长率分别是纯PVC的1.13倍和2.26倍;通过扫描电子显微镜分析了聚合物的增韧机理。

Atom transfer radical polymerization （ATRP） was applied to prepare polymethyl methylcarylate-Br（ PMMA-Br）, polybutyl acrylate-Br（PBA-Br） and the block copolymer（PMMA-b-PBA-Br）. They were further azided and then were used to modify single walled carbon nanotubes （SWNT）. The modification results were characterized by FTIR spectrum, Raman spectrum, TG and TEM. Different kinds of modified SWNTs were added into PVC to prepare nanocomposites. The experimental results showed that the mechanical properties were dramatically improved when 0. 1 g modified SWNT were added into lO0 g PVC . The impact strength of PVC/PMMA-b-PBA - SWNT was 4 times of of pure PVC. PVC/PMMA - SWNT＇s impact strength, tensile strength and elongation at break were increased by 220% , 16% and 250% respectively. PVC/PBA - SWNT＇s tensile strength and elongation at break was 1.13 times and 2.26 times as much as the pure PVC. The toughening mechanism of the nanocomposites was analyzed with SEM.