微晶纤维素/不饱和聚酯复合材料的力学与热稳定性研究

Study on the Mechanical and Thermal Stability of Microcrystalline Cellulose/Unsaturated Polyester Composites

以不饱和聚酯(UP)为基体,硅烷偶联剂(KH-550)改性微晶纤维素(MCC)为填充材料,采用共混浇注方法制备微晶纤维素/不饱和聚酯树脂(MCC/UPR)复合材料。运用SEM、DMA、TG研究了MCC及硅烷偶联剂对MCC/UPR复合材料的力学性能和热降解行为的影响。结果表明:添加MCC能够提高UPR的力学性能,当添加量超过45%(wt)时力学性能明显下降。KH-550硅烷偶联剂能够改善MCC与UPR的界面相容性,提高树脂的黏结性,提高复合材料的机械性能。在实验条件下MCC为30%(wt)时,拉伸强度、冲击强度、弯曲强度较纯UPR材料提高了81.86%,82.26%和53.76%;相同条件下,偶联剂改性后的MCC/UPR复合材料力学性能比未经处理的分别提高了19.70%,11.50%和6.83%。MCC使UPR玻璃化转变温度提高,刚性降低。

The unsaturated polyester（UP）was used as the matrix and the microcrystalline cellulose（MCC）modified by silane coupling agent（KH-550） was used as the filler, and then the microcrystalline cellulose/unsaturated polyester resin（MCC/UPR） composites was prepared by blendingpouring methods. The effects of MCC contents and silane coupling agents on the mechanical properties and thermal degradation behaviors of MCC/UPR composites were investigated by the means of SEM, DMA and TG. The results showed that the MCC could improve the mechanical properties of UPR composites. However, when the content of MCC exceeded 45%（wt）, the mechanical properties decreased obviously. The KH-550 could improve the interfacial compatibility between MCC and UPR, the adhesion of the resin and the mechanical properties of the composite materials. Under the experimental conditions, when the content of MCC was 30%（wt）, the tensile strength, impact strength and bending strength increased by 81.86%,82.26% and 53.76% respectively compared with the pure UPR materials; under the same conditions, the coupling agent modified MCC/UPR composites（K-MCC/UPR）were improved by 19.70%, 11.50% and 6.83% respectively compared with the unmodified ones. The MCC made the glass transition temperature of UPR increase and the rigidity decrease.