交联壳聚糖/聚乙烯醇的制备及其在竹材中的构建

以戊二醛为交联剂制备壳聚糖/聚乙烯醇互穿聚合物,并对其溶胀性进行表征。采用扫描电子显微镜(SEM)、透射电子显微镜(TEM)和傅里叶变换红外光谱(FT-IR)研究聚合物的微观形貌和化学结构特征。将戊二醛、壳聚糖及聚乙烯醇混合后通过真空浸渍的方式注入竹材中并发生交联反应,测试处理材的干缩湿胀和防霉防腐性能。结果表明:壳聚糖可均匀分散在聚乙烯醇中,成膜均匀,两者相容性较好; 处理材在浸水-干燥3次循环下干缩率为6.9%～7.4%,在吸湿-干燥3次循环下的干缩率为1.4%～1.5%,吸水和吸湿抗胀率最高达34.5%; 壳聚糖/聚乙烯醇互穿聚合物在竹材中的构建提高了竹材的防霉和防腐效果。未处理材在试验开始后霉菌便迅速长满,处理材霉菌孢子萌发推迟,生长缓慢,处理后竹材经褐腐菌密粘褶菌和白腐菌彩绒革盖菌侵染后的质量损失率为10.0%和5.4%,与未处理材相比分别减少了8.0%和8.1%。竹材内原位构建壳聚糖/聚乙烯醇聚合物网络,既能够提高竹材的尺寸稳定性,又增加了竹材的防霉和防腐性能,同时为解决竹材尺寸稳定性差和易霉变腐朽问题提供新途径。
The interpenetrating polymer of chitosan and poly(vinyl alcohol)crosslinked by the glutaraldehyde(GA)was prepared, and the swelling properties were evaluated. Morphological and chemical structures of the polymers were investigated by the scanning electron microscopy(SEM), transmission electron microscopy(TEM)and Fourier transform infrared spectroscopy(FT-IR), respectively. The formulation of the polymer was composed of glutaraldehyde, chitosan and poly(vinyl alcohol), which was injected into bamboo by using the vacuum impregnation method and followed by a crosslinking reaction under a proper temperature. The shrinkage and swelling, mold and decay resistance of the treated material were investigated. Results are presented as follows: the chitosan can be evenly dispersed in the poly(vinyl alcohol), forming a uniform polymer film, indicating that the chitosan and poly(vinyl alcohol)have good compatibility in the crosslinked system; shrinkage values of the treated bamboo were in the range of 6.9%-7.4% under water-dry cycles and 1.4%-1.5% under moisture-dry cycles, with an anti-swelling efficiency of 34.5%; the construction of the glutaraldehyde crosslinked chitosan/poly(vinyl alcohol)interpenetrating polymer can improve the mold and decay resistance of bamboo. The untreated bamboo was quickly covered with mold at the beginning of the experiment, while the spores germinated and developed slowly on the treated bamboo. In addition, the treated bamboo resisted Gloeophyllun trabeum and Trametes versicolor effectively. The mass losses of the treated bamboo were 10.0% and 5.4%, respectively, which decreased by 8.0% and 8.1% compared with the untreated controls. The in-situ construction of the chitosan/poly(vinyl alcohol)polymer network in the bamboo not only increased the dimensional stability of bamboo, but also prevented bamboo from decay and mold, which provided a novel method for simultaneously solving the problems of dimensional instability and fungi attacking. Further research in this field will be focused on prolonging the service life of bamboo, as well as widening the application of