抗紫外生物基不饱和聚酯/纳米木质素复合材料的制备及性能研究

Preparation and Properties of UV-Resistant Bio-based Unsaturated Polyester/Lignin Nanoparticles Composites

以生物基单体衣康酸、丁二酸、异山梨醇、1,3-丙二醇为原料,通过熔融缩聚制备全生物基不饱和聚酯(UP),以UP为基体,引入溶解-沉降法得到的纳米木质素(LNP)制备生物基UP/LNP复合材料。以傅里叶红外光谱仪(FTIR)和凝胶渗透色谱仪(GPC)为手段,表征了生物基UP的分子结构与分子量;扫描电子显微镜(SEM)测试表明LNP的形貌为棒状,长度180~220 nm、直径30~36 nm;同时利用万能拉伸机、热重分析仪测试了复合材料的性能。结果表明,当LNP的添加量为0.5%时,复合材料的弹性模量、热分解温度(T d5%)分别为2222.67 MPa、259.67℃,与纯UP相比分别增加270.34 MPa、6.00℃。紫外老化实验表明,随紫外光照射时间的增加,UP以及UP/LNP复合材料的拉伸性能均出现先上升后下降的现象,其中纳米复合材料的变化较为平缓;紫外照射200 h后,较之未照射样品,UP的拉伸性能出现了下降,而其纳米复合材料的拉伸性能变化不大,表明LNP的加入提高了UP的抗紫外线能力。

Bio-based monomeric itaconic acid,succinic acid,isosorbide and 1,3-propanediol were used as raw materials to prepare fully bio-based unsaturated polyester(UP)by melting polycondensation.Using it as the matrix,the nano-lignin(LNP)obtained by dissolution-sedimentation method was introduced to prepare bio-based UP/LNP composites.The molecular structure and molecular weight of bio-based UP were characterized by Fourier infrared spectroscopy(FTIR)and gel permeation chromatography(GPC).Scanning electron microscopy(SEM)test shows that the morphology of LNP is rod-shaped,with a length of 180-220 nm and a diameter of 30-36 nm.At the same time,the performance of the composite is tested by universal stretching machine and thermogravimetric analyzer,and the results shows when the addition amount of LNP is 0.5%,the elastic modulus and thermal decomposition temperature(T d5%)of the composite are 2222.67 MPa and 259.67℃,respectively,which increases by 270.34 MPa and 6.00℃comparing with pure UP.The ultraviolet aging test shows that with the increase of ultraviolet irradiation time,the tensile properties of UP and UP/LNP composites first increase and then decrease,and the changes of nanocomposites are relatively flat.After 200 h of UV irradiation,the tensile properties of UP decrease comparing with the unirradiated sample.However,the tensile properties of its nanocomposites could not change much.It shows that the addition of LNP improves the UV resistance of UP.