木质素/PVA发泡材料改性研究

目的探究甘油用量对木质素/PVA发泡材料性能的影响。方法采用水浴加热方法对PVA和木质素进行溶解处理,再加入不同量的甘油,以不加甘油的空白样为对照,测试及表征其性能。结果随着甘油用量的增加,发泡材料的拉伸强度先增加后降低,甘油用量为8%时材料的拉伸强度达到最大,为1.26 MPa;断裂伸长率逐渐增大,从最初的37%增大到167%;表观密度先下降后上升,最低为0.278g/cm3;吸水率逐渐降低,最低达到15.22%。SEM测试表明,甘油的加入改善了发泡材料的空隙结构,但加入过多的甘油会破坏泡孔结构。TGA结果表明,随着甘油用量的增加,所得复合材料的热稳定性降低,热分解起始温度和分解最大速率温度都逐渐降低。结论甘油对木质素/PVA发泡材料的性能影响较大,加入适量的甘油对材料的力学性能、泡孔结构和热稳定性都有很强的促进作用。

Modification of Lignin/PVA Foam Materials

The work aims to study the effect of glycerin on the properties of lignin/PVA foam materials. PVA and lignin were dissolved by means of water bath heating, and then the performance was tested and characterized by adding different amounts of glycerin with a blank sample without glycerin as the control. With the increase of glycerin, the tensile strength of the foam materials increased first and then decreased. The tensile strength of the material reached the maximum (1.26 MPa) when the amount of glycerin was 8%. The elongation at break increased gradually from initially 37% to 167%. The appearance density decreased first and then increased and its minimum was 0.278 g/cm3. The water absorption decreased gradually and reached the minimum of 15.22%. The SEM test results showed that, the addition of glycerin improved the void structure of the foam materials, but adding too much glycerin would destroy the foam structure. TGA results showed that, with the increase of glycerin, the thermal stability of the composites decreased. The thermal decomposition starting temperature and decomposition temperature at the maximum rate were reduced gradually. In conclusion, glycerin has a greater influence on the performance of lignin/PVA foam materials. The addition of an appropriate amount of glycerin will strongly promote the mechanical properties, foam structure and thermal stability of the materials.