端羧基修饰单宁酸/没食子酸环氧树脂复合材料的制备与性能研究

Preparation and performance of carboxyl⁃terminated tannic acid/gallic acid⁃based epoxy composite

通过A_(2)+B_(3)一步法及缩聚反应分别制备生物质超支化聚合物(CTMTA)和没食子酸环氧树脂(GAER),采用熔融共混法制备了没食子酸环氧树脂(GAER)/甲基四氢苯酐(MTHPA)/2-甲基咪唑(2-MI)/超支化聚合物(CTMTA)复合材料。利用傅里叶变换红外光谱仪(FTIR)、核磁共振仪(1H-NMR)、差示扫描量热仪(DSC)、扫描电子显微镜(SEM)、力学性能和吸水率等试验,研究了CTMTA含量对GAER/MTHPA/2-MI复合体系性能的影响。结果表明,CTMTA的加入能提高复合体系的力学性能和吸水率,降低复合体系的固化温度。当CTMTA含量为1.5%(质量分数,下同)时,GAER/MTHPA/2-MI/CTMTA复合体系的力学性能和吸水率最佳,拉伸强度、断裂伸长率、冲击强度和吸水率分别比GAER/MTHPA/2-MI体系提高了33%、37%、47.6%和45.5%。GAER/MTHPA/2-MI/CTMTA复合体系的最佳固化工艺参数为110℃/20 min。

A bio‑based hyperbranched polymer(CTMTA)and a gallic acid‑based epoxy resin(GAER)were prepared through an A_(2)+B_(3) one‑step method and a polycondensation reaction,respectively.The GAER/MTHPA/2‑MI/CTM‑TA composites were prepared using a melt blending method.The effects of CTMTA content on the properties of the GAER/MTHPA/2‑MI composites were investigated using by FTIR,1 H‑NMR,DSC,SEM,mechanical measure‑ment,and water absorption.The results indicated that the addition of CTMTA improved the mechanical properties and water absorption rate of the composites but reduced their curing temperature.The composites exhibited maximum me‑chanical properties and water absorption rate at a CTMTA content of 1.5 wt%.Compared to the GAER/MTHPA/2‑MI composite system,the GAER/MTHPA/2‑MI/CTMTA composites presented an increase in tensile strength,elon‑gation at break,impact strength,and water absorption rate by 33%,37%,47.6%,and 45.5%,respectively.The optimum curing parameter of the GAER/MTHPA/2‑MI/CTMTA composite system was determined to be 110℃/20 min.