摘要
研究了不同丙烯酸酯嵌段聚合物(LA-polymer)弹性体添加量对酚醛(PF)/环氧树脂(EP)固化体系机械性能(本体拉伸,拉伸剪切,断裂韧性)及热降解行为的影响。采用扫描电镜(SEM)对断面形貌进行表征,探讨了弹性体增韧改性环氧树脂的机理,采用CoatsRedfern(CR)法探讨LA-polymer弹性体添加量对PF/EP体系降解动力学的影响。研究表明,添加适量LA-polymer能增韧环氧树脂,有效保留本体拉伸强度并提高本体柔性;拉伸剪切强度测试表明,当LA-polymer添加量为20质量份(100质量份环氧树脂中加入量,下同)时,固化体系拉伸剪切强度较空白样提高了40%;拉伸断面形貌表征表明,LA-polymer的添加能实现本体的脆-韧转变,裂纹扩展得到有效钝化;热失重(TGA)研究表明LA-polymer的添加会一定程度降低固化体系的热分解温度,并改变固化体系降解动力学模型(由Fn向Dn转变)。
The effect of crylic block copolymer（LA-polymer） content on the mechanical properties（tensile strength, lap shear strength and fracture toughness） and the thermal degradation behavior of the phenolic（PF）/epoxy（EP） resin curing system were studied. The morphology characterization of the tensile fracture surfaces and was investigated by SEM and the toughening mechanism was discussed. The Coats-Redfern（CR） method was used to study the influence of LA-polymer on the thermal degradation kinetics of PF/EP resin curing system. The research indicated that the appropriate amount of LA- polymer added not only toughened the PF/EP system, but also retained the bulk tensile strength and improved the flexibility; when the LA-polymer amount was 20 phrs, the lap shear strength was improved by 40 percent. The morphology reults showed that adding LA-polymer achieved the transition from brittle fracture to ductile fracture and the crack development was blunted. The adding LA-polymer decreased the thermal stability and changed the degradation kinetics model.
出处
《粘接》
CAS
2016年第7期51-56,共6页
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