苯并三唑类光稳定剂的合成及在剑麻纤维基复合材料中的应用

Synthesis of Benzotriazole Light Stabilizers and Their Application in Sisal Fiber Based Composite Materials

通过溶液聚合合成了一种梳状复合型高分子光稳定剂P(HAPBT-co-MTMP-co-OA-co-m PEGA)。采用红外光谱、核磁共振、热重分析对高分子光稳定剂进行了表征,结果表明,高分子光稳定剂的热分解温度明显高于中间体(2',4'-二羟基苯基)-2H-苯并三唑(DHPBZ)的分解温度。将该光稳定剂应用到PP/剑麻纤维(SF)与PE/SF复合材料中能提高其抗紫外老化性能。通过测试复合材料老化前后的拉伸性能、接触角、羰基指数、乙烯基指数、水萃取损失率、热迁移损失率、扫描电镜等研究了光稳定剂的稳定化效果,并与低分子紫外线吸收剂UV-P的应用性能进行对比。结果表明,老化50 d后,添加高分子光稳定剂的PP/SF和PE/SF复合材料拉伸强度保持率分别比其空白复合材料少下降了37.41%和38.17,而添加UVP的PP/SF和PE/SF复合材料的拉伸强度保持率分别比其空白复合材料少下降了12.72%和12.85%。添加高分子光稳定的PP/SF和PE/SF复合材料羰基指数分别增加了0.033和0.018,乙烯基指数分别增加了0.07和0.039,增加幅度均较小;接触角测试结果表明无论是否添加光稳定剂的PP/SF和PE/SF接触角均随老化程度的加深而降低,但添加光稳定剂的复合材料接触角降低幅度明显低于空白复合材料;扫描电镜显示光稳定剂的加入使材料老化后表面裸露出剑麻纤维的表面积相对较小,产生的裂纹也较少;高分子光稳定剂具有优于UV-P的耐热水萃取与耐热迁移性能。

A kind of comb like polymer light stabilizer （P（HAPBT-CO-MTMP-CO-OA-CO-mPEGA） was synthesized by solution copolymerization. The structure of copolymers was confirmed by FT-IR, 1H-N and TGA. The results show that the thermal decomposition temperature of the polymer light stabilizer is significantly higher than the decomposition temperature of the intermediate（2＇, 4＇-dihydroxy-phenyl）-2H-benzotriazole. Then the polymer light stabilizer was applied to the polypropylene/sisal fiber（PP/SF） and polyethylene（PE）/SF composite materials to improve the UV aging resistance of the materials. The UV aging properties of SF/PP and SF/PE Wood plastic composites were studied by tensile strength retention rate, contact angle of material surface, carbonyl index, vinyl index, loss rate of water extraction and loss rate of heat extraction before and after aging. The microstructure of the composite was observed by SEM, and the light stability properties of the polymer light stabilizer and UV-P were compared. The results show that the tensile strength retention rates of the PP/SF and PE/SF composites with addition of the polymer light stabilizer are decreased by 37.41% and 38.17 % respectively less than that of the blank composites after 50 d of UV light aging. While the tensile strength retention rates of the PP/SF and PE/SF composites with the UVP light stabilizer are decreased by 12.72 % and 12.85 % respectively less than that of the blank composites. The vinyl index of PP/SF and PE/SF composites with polymer light stability increases by 0.033 and 0.018 respectively, the carbonyl index increases by 0.07 and 0. 039 respectively, but the increasing range is very narrow. The results of contact angle test show that the contact angle of PP/SF and PE/SF decrease with the increase of UV aging degree, regardless of whether the light stabilizer is added or not, but the contact angle of the composite with light stabilizer is significantly lower than that of the blank. SEM show that with the addition of light stabilizers for polymer composites after aging, exposed sisal fiber surface area is relatively small, fewer cracks. The polymer light stabilizer has better hot water extraction resistance and heat transfer resistance performances than the UV-P.