异氰酸酯/硅烷偶联剂接枝改性杨木粉的制备及其表征

摘要

以N,N-二甲基甲酰胺(DMF)为溶剂、辛酸亚锡为催化剂,采用4,4′-亚甲基双(异氰酸苯酯)/γ-氨丙基三乙氧基硅烷(MDI/KH550)对杨木粉(PWP)表面接枝化学改性.研究了反应物料比、反应温度、反应时间及催化剂用量对杨木粉改性反应的影响,并通过接触角测量、元素分析、红外光谱(FT-IR)、13C固体核磁共振光谱(13C CP-MAS NMR)及扫描电子显微镜(SEM)表征了改性杨木粉的结构与表面性能.研究结果表明,以MDI与PWP活性羟基物质的量比2∶1,MDI与KH550物质的量比1∶1,120℃反应2h,制备的MDI/KH550改性杨木粉质量增加率为40 ％～60％,催化剂对改性反应无明显影响；改性后杨木粉疏水性增强.%The poplar wood powder (PWP) was surface modified by 4,4'-methylenebis (phenyl isocyanate)/ γ-aminopropyltrie-thoxysilane(MDI/KH550) in N,N-dimethylformamide (DMF). The effects of material ratio, reaction temperature, reaction time and dosage of catalyst on the reaction were investigated. The chemical structure and surface properties of modified poplar wood powder were characterized by contact angle measurement, elemental analysis, FT-IR, 13C CP-MAS NMR and SEM. The results showed that the weight percent gain (W) of MDI/KH550 modified PWP increased by 40-60% when MDI reacted with PWP in molar ratio of 2:1 at 120 ℃ for 2 h, and the catalyst had no appreciable effect on the modification reaction. The hydrophobicity of modified PWP was improved.