摘要
通过SEM-EDS、XRD及^(29)Si MAS固体NMR技术分析了无助熔剂型可陶瓷化阻燃硅橡胶在高温裂解后的微观结构与化学组成,并提出了该陶瓷化硅橡胶的成瓷机理。结果表明:在较低温度下,硅橡胶裂解生成SiC及五配位硅,起到“锚固”作用,且硅橡胶的主要分解产物以类似气相法白炭黑的结构残留,具有高烧结活性;在更高温度下,氧化硅及硅酸盐均演变为高温稳定相,且残留的过量氧化硅促使硅酸盐产生液相,这有利于残留粉体间的“融合”和强界面相互作用的建立;此外,液相的形成有助于缩小和消除硅橡胶分解中产生的孔洞,从而实现致密化效应,这些因素对于提高陶瓷体的强度具有重要作用。
The microstructures and chemical composition of ceramizable flame retardant silicone rubber without fluxing agent after high temperature pyrolysis were analyzed using SEM-EDS,XRD and ^(29)Si MAS Solid NMR,and its ceramization mechanism was investigated.The results showed that at lower temperatures,the pyrolysis of silicone rubber generated SiC and Five-coordination Si(Si v),which played an"anchoring"role,while the main decomposition products of silicone rubber remained in a fumed silica-like structure with high sintering activity.At higher temperatures,both silica and silicate transformed into their high-temperature stable phases,and the excess residual silica promoted liquid phase formation in the silicates,which was beneficial for the"fusion"among the residual powder particles and even for the strong interfacial interaction.Furthermore,the generation of silicate liquid phase was favorable for the reduction and disappearance of the pores generated during the pyrolysis of silicone rubber,thus producing a densification effect.All these factors improved the mechanical strength of the resulting ceramic body.
作者
王韶晖
秦永法
龚雪冰
WANG Shaohui;QIN Yongfa;GONG Xuebing(Anhui Estone Materials Technology Co.,Ltd.,Bengbu 233400,China;Bengbu Estone Polymer Composites Co.,Ltd.,Bengbu 233400,China)
出处
《特种橡胶制品》
2025年第5期1-10,共10页
Special Purpose Rubber Products
关键词
陶瓷化硅橡胶
阻燃
成瓷机理
高温裂解
ceramizable silicone rubber
flame retardant
ceramization mechanism
high temperature pyrolysis
