有机发泡剂制备聚乙烯醇-碱木质素发泡材料及性能研究
Preparation and properties of polyvinyl alcohol alkali lignin foam materials with organic foaming agent
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摘要: 为改进造纸黑液中木质素再利用情况和PVA泡沫的力学性能,以甲醛为交联剂,采用BSH发泡剂发泡制备聚乙烯醇-碱木质素发泡材料(PLFM)并测定其相关性能。结果表明:相对于PVA用量,发泡剂用量0.5%、甲醛用量0.8mL/g、麦草碱木质素用量30%时,制备的PLFM力学性能最好,拉伸强度最大,为28.94MPa;吸水率最低,为2.455倍;表观密度0.28g/cm3。PLFM的耐溶剂性能随碱木质素用量的增大而降低;碱木质素、PVA和甲醛交联较好,发生芳环的5位取代;泡沫均匀、孔隙规则;具有较好的生物相容性;热稳定性不因碱木质素的加入而降低,且热降解性好。Abstract: According to the principle of organic foaming agent benzene sulfonyl hydrazide (BSH), polyvinyl alcohol (PVA) and wheat straw alkaline lignin, crosslinked by formaldehyde, were used to prepare foaming materials with high performance for improving the reuse of lignin waste from paper industries and the properties of PVA foaming materials (PLFM). Results showed that: PLFM reached the maximum tensile strength (28.94MPa) and the most uniform structure when the amount of foaming agent was 0.5%, formaldehyde 0.8mL/g and alkali lignin 30%, relative to the amount of PVA. The least water absorption was 2.455 and the apparent density remained 0.28g/cm3 when the alkali lignin content was 30%. The water resistance of PLFM decreased as the amount of alkali lignin increased. The crosslinks between components were sufficient and the C-5' was substituted in the central aromatic ring; uniform and micro pores were observed in samples and PLFM was biocompatible. The thermal stability of PLFM did not decrease as more alkali lignin was added and thermal degradation of PLFM was good.