摘要
以新疆地产风化煤(weathered coal)为原料通过硝酸氧解工艺制备黄腐植酸(fulvic acid,FA),并对黄腐植酸进行季铵化改性,合成黄腐植酸季铵盐(quaternary fulvic acid,QFA).以皂石为原料通过超声波辐照法制备黄腐植酸季铵盐插层皂石(QFA-saponite).以丙交酯和QFA-saponite为原料,在辛酸亚锡催化作用下,制备了聚乳酸/黄腐植酸季铵盐插层皂石(PLA/QFA-saponite)纳米复合材料.通过正交实验探讨了聚合时间、聚合温度、催化剂和QFA-saponite加量对PLA分子量的影响,其最优反应条件为反应12 h、辛酸亚锡加量3%、温度150℃、QFA-saponite加量为2%,该正交优化条件下合成的PLA/QFA-saponite纳米复合材料的重均分子量可达95300.红外光谱分析表明黄腐植酸中引入了季铵根离子.X-射线衍射(XRD)对QFA-saponite的分析表明,QFA-saponite呈现部分剥离与插层共存的状态,其层间距达到1.57 nm,比皂石层间距增大0.17nm.用XRD、示差扫描量热仪(DSC)、偏光显微镜(POM)、热重分析(TGA)等方法对复合材料进行结构表征.结果表明,PLA/QFA-saponite纳米复合材料具有剥离型结构,QFA-saponite有效改善复合材料的结晶性能和热稳定性.抗菌实验表明,黄腐植酸季铵盐插层皂石对大肠杆菌(Escherichia coli),枯草杆菌(Bacillus subtilis),黑曲霉菌(Aspergillus)及青霉(Penicillium)有较强的抑菌效果,同时聚乳酸/黄腐植酸季铵盐插层皂石纳米复合材料也有良好的抗菌性能.
The fulvic acid（ FA） was prepared with Xinjiang local weathered coal by HNO3 oxidation technology,and then quaternary fulvic acid（ QFA） was synthesized with FA. The QFA intercalated saponite（ QFA-saponite） was prepared with saponite by ultrasonic intercalation. Poly（ lactic acid）（ PLA） /QFAsaponite nanocomposites were in situ polymerized with D,L- lactide and QFA-saponite and with stannous octoate as the catalyst. The effects of polymerization time,polymerization temperature,the addition amount of catalyst and QFA-saponite on the molecular weight of PLA were investigated by orthogonal experiment,respectively. The optimum conditions were as follows： polymerization time was 12 h,the addition amount of stannous octoate was 3 wt%,polymerization temperature was 150 ℃ and the addition amount of QFA-saponite was 2 wt%,respectively. Under the optimum conditions,the molecular weight of PLA / QFA-saponite nanocomposites was 95300. FTIR analysis showed that the quaternary ammonium ions were introduced into fulvic acid. The structure of QFA-saponite was characterized by X-ray diffraction（ XRD）. It was shown that QFA-saponite had co-existence structure with intercalation and partial exfoliation,and its basal spacing was1. 57 nm,which was increased by 0. 17 nm compared with that of saponite. The structure of PLA / QFA-saponite nanocomposites was investigated by XRD,polarized optical microscopy（ POM） and thermal gravimetric analysis（ TGA）,respectively. The results showed that exfoliated PLA based nanocomposites were obtained by in situ polymerization,and QFA-saponite significantly improved the crystallinity properties and thermal stability of PLA. Antibacterial experiments showed that QFA-saponite had antibacterial and sterilization properties against Escherichia coli,Bacillus subtilis,Aspergillus and Penicillium. Meanwhile,PLA / QFA-saponite nanocomposites also had good antibacterial properties.
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2015年第7期769-777,共9页
Acta Polymerica Sinica
基金
国家自然科学基金(基金号51163013)资助项目
