木质素磺酸铵对聚乳酸/木纤维可生物降解复合材料力学与热性能的影响

为探讨生物质资源改善复合材料的界面及综合性能的可行性,以木纤维(WF)为基体,聚乳酸(PLA)为增强体,添加氧化改性木质素磺酸铵(OMAL),采用高速混合-平板热压工艺制备环境友好型OMAL-PLA/WF复合材料。研究了OMAL对OMAL-PLA/WF复合材料力学和热性能的影响。结果表明:在WF与PLA质量比为7∶3的复合体系中,OMAL对提高OMAL-PLA/WF复合材料的静曲强度、弹性模量以及内结合强度具有促进作用。OMAL添加量为15wt%~20wt%时,OMAL-PLA/WF复合材料的力学性能最好;当OMAL添加量为20wt%时,与PLA/WF对照样相比,OMAL-PLA/WF复合材料的热分解起始温度降低45℃,热分解速率特征峰温度提前107℃,残渣量增加5.3%,玻璃化转变温度、冷结晶温度和熔融温度均向低温方向移动,储能模量和损耗角正切值增大,玻璃态阶段的热稳定温度范围提高约20℃。

Influence of ammonium lignosulphonate on mechanical and thermal properties of polylactic acid/wood fiber biodegradable composites

In order to investigate the feasibility of biomass resources improving the interface and comprehensive properties of bio-composites, the oxidation modification ammonium lignosulphonate (OMAL) was used to produce the environment friendly OMAL-polylactic acid (PLA)/wood fiber (WF) composites by the high speed mix-flat hot pressing process with WF as matrix and PLA as reinforcement. The influence of OMAL on mechanical and thermal properties of OMAL-PLA/WF composites was investigated. The results show that OMAL can improve the modulus of rupture, elastic modulus and internal bond strength of OMAL-PLA/WF composites with mass ratio 7:3 of WF to PLA, and the optimized mechanical properties are achieved with OMAL dosage of 15wt%-20wt%. When the OMAL dosage is 20wt%, the thermal decomposition initial temperature decreases 45 ℃, the characteristic peak of thermal decomposition rate arises 107 ℃ in advance, the residue quantity increases by 5.3%, the glass transition temperature, cold crystallization temperature and melting temperature shift to low temperature, the storage modulus and loss tangent increase with the temperature range of the platform stage increases about 20 ℃ compared to that of PLA/WF composites.