羧甲基纤维素接枝甲基丙烯酸甲酯对稻壳水泥复合材料的增强作用

Reinforcement Effect of Carboxylic Methylcellulose-g-Poly Methyl Methacrylate on Rice Hull-cement-based Composites

利用羧甲基纤维素和甲基丙烯酸甲酯在水介质中用过硫酸钾为引发剂,合成稻壳-水泥复合材料的偶联剂——羧甲基纤维素接枝甲基丙烯酸甲酯(CMC-g-PMMA)。共聚物采用傅立叶红外光谱(FTIR)、扫描电镜(SEM)进行表征。并采用X射线能量散射分析(EDXA)测量共聚物中葡萄糖环上甲基丙烯酸甲酯的个数。采用CMC-g-PMMA作为植物纤维表面处理剂,与水泥一并制成复合材料。对材料密度、24h吸水厚度膨胀率、抗弯强度进行了测试(万能力学实验机),对表面形貌进行观察(体视显微镜)。结果表明:添加CMC-g-PMMA可大幅度提高稻壳-水泥复合材料的抗弯强度和弹性模量,当稻壳比例为20%,CMC-g-PMMA比例为1%时,抗弯强度和弹性模量分别为未添加助剂试样的2.27倍和2.71倍。同时讨论了CMC-g-PMMA的增强机理。

The synthesis of carboxylic methylcellulose-g-poly （Methyl Methacrylate） was carried out by potassium persulfate induced graft copolymerization in homogeneous aqueous medium. These graft copolymers were characterized by Fourier transform infrared spectra （FTIR） and scanning electron microscopy （SEM）. In addition, the graft rate was measured by energy-dispersive X-ray analysis （EDXA） methods. The synthesis of carboxylic methylcellulose-g-poly Methyl Methacrylate was adding to the composites as surface treatment with the contrast sample adding latex and MDI. The density, expansion after absorbing water within 24 hours and the flexural strength of the composites were measured, and the surface topography was observed. The sample adding carboxylic methylcellulose-g-poly Methyl Methacrylate （CMC-g-PMMA） had higher flex- ural strength and flexural modulus. When the composites contained 20% hull and 1% CMC-g-PMMA, the flexural strength and flexural modulus increased by 1.27 times and 1.71 times compared with the sample contained 20% rice hull only.