碳纤维增强双马来酰亚胺树脂预浸料铺覆黏性及其储存老化行为

Placement tack and storage aging behavior of carbon fiber reinforced bismaleimide prepreg

将碳纤维增强双马来酰亚胺树脂预浸料CCM40J/HT-280分别置于4种储存环境(真空、N2、O2、空气)进行室温老化实验,研究了预浸料铺覆黏性与储存环境和老化时间的关系,对不同环境下黏性失效前后的样品进行了DSC、流变、红外光谱分析。针对不同黏性级别的预浸料,采用热压罐成型工艺制备了复合材料层合板,对层合板内部成型质量及复合材料力学性能进行了研究。结果表明,真空和N2环境储存下的CCM40J/HT-280预浸料黏性失效周期相比于O2与空气中的样品延长约40%。DSC和流变测试结果表明,老化后树脂的交联程度大于新鲜树脂,树脂最低黏度也显著增大,O2环境下的样品表现的更为明显;对红外光谱特征峰分析表明,O2环境储存条件下树脂交联反应程度高于真空环境,说明O2对双马来酰亚胺树脂室温下的老化具有促进作用。黏性失效的预浸料制备的CCM40J/HT-280复合材料内部多为层间或层内的密集孔隙,其弯曲强度下降约13.0%、弯曲模量下降约6.5%,层间剪切强度下降约10.7%。

The carbon fiber reinforced bismaleimide prepreg CCM40 J/HT-280 was placed in different storage environments(vacuum,N2,O2,air)for room temperature aging experiments,and the relationship among the prepreg tack and storage environment and aging time was studied.The samples before and after the tack failure in different environments were analyzed by DSC,rheological and infrared spectroscopy.The CCM40 J/HT-280 composites were prepared by autoclave molding process with the prepreg in different tack levels,and both the internal molding quality and mechanical properties of the composites were studied.The results show that the tack failure period of the CCM40 J/HT-280 prepreg under the vacuum and N2 storage environment is about 40%longer than that of the sample in O2 and air.DSC and rheological test results show that the degree of crosslinking of the resin after aging is greater than that of virgin resin with the minimum viscosity significantly promoted,which is more obvious in the O2 environment.The analysis of the characteristic peaks by infrared spectrum shows that the degree of crosslinking reaction of the resin in the O2 environment storage is higher than that in the vacuum environment,indicating that O2 promotes the aging of the bismaleimide resin at room temperature.The CCM40 J/HT-280 composites prepared by the tack failure prepreg have dense pores inside or between layers,and the flexural strength of the composites decreases by about 13.0%,the flexural modulus decreases by about 6.5%,and the interlaminar shear strength decreases by about 10.7%.