毛竹采伐剩余物制备可降解膜的研究

为解决传统塑料薄膜难降解、制备原料不可再生等问题,以毛竹采伐剩余物为原料,通过碱化、醚化以及羧甲基化反应制备可降解薄膜。利用红外光谱、扫描电子显微镜及X射线衍射仪等手段,分析、研究了竹粉碱化、醚化等反应后化学官能团、表面微观结构及结晶度的变化。通过增稠剂海藻酸钠与淀粉改性,对比分析不同工艺条件下毛竹采伐剩余物可降解膜力学性能。结果表明,经碱化和醚化后毛竹采伐剩余物中木质素被脱除。纤维素内部发生分子重排,晶体结构改变,氢键作用减弱,结晶度下降。通过增稠剂海藻酸钠与淀粉改性,薄膜的拉伸强度明显增加,但断裂伸长率有所下降。覆盖薄膜后的土壤湿度下降趋势较未覆盖薄膜的土壤明显变缓,保墒性良好。

Study on preparation of biodegradable film from moso bamboo logging residues

In order to solve the problem that traditional plastic film is difficult to be degraded and the raw material is not renewable, the moso bamboo logging residues were used for preparing biodegradable film by alkalization, etherification and carboxymethylation. The changes of chemical functional groups and surface microstructure after alkalization and etherification of bamboo powder were analyzed and studied by means of infrared spectroscopy and scanning electron microscope. The film was modified by sodium alginate and starch, and the mechanical properties of biodegradable film of bamboo logging residues under different processing conditions were compared and analyzed. The results showed that the lignin was removed from the cutting residue of bamboo after alkalization and etherification. After alkalization, etherification and carboxymethylation, molecular rearrangement occurred in cellulose, crystal structure changed, hydrogen bonding weakened, and crystallinity decreased. When the sodium alginate and starch added as thickener, the tensile strength of the film was obviously increased, but the tensile elongation at break was decreased. The soil moisture content decreased more slowly after mulching the film than that without mulching the film, which indicated the film had good moisture retention.