ZrSi_2/硼酚醛泡沫的制备及其裂解产物的增强机制

以ZrSi_2颗粒填充硼酚醛树脂制备了一种耐高温且裂解后结构较为完整的泡沫复合材料。研究了ZrSi_2颗粒质量分数对泡沫复合材料固化机制、高温裂解行为及裂解前后压缩性能的影响,并分析了ZrSi_2颗粒对泡沫复合材料裂解产物的增强机制。结果表明:添加的ZrSi_2颗粒虽未参与硼酚醛树脂的固化交联,但会和硼酚醛树脂裂解放出的气体挥发物发生化学反应,提高了裂解产物的残炭率和压缩比强度。当添加的ZrSi_2颗粒质量为硼酚醛树脂质量的10%时,裂解产物的残炭率和压缩比强度提高最为显著。ZrSi_2/硼酚醛泡沫经过裂解后,ZrSi_2颗粒作为第二相粒子钉扎在裂解产物的孔壁上,化学反应使得部分裂解气体挥发物被吸收并转化为固相产物,明显减少的缺陷提高了裂解产物的力学性能。

Preparation of ZrSi2/boron-modified phenolic foam and strengthen mechanism of pyrolytic product

A kind of high-temperature resistant foam composites with relatively integrated structure after pyrolysis was prepared with ZrSi2 particles filling boron-modified phenolic resin.The curing mechanism,high-temperature pyrolytic behaviors,compression performances before and after pyrolysis of foam composites were investigated with respect to ZrSi2 particle mass fraction,and the strengthen mechanism of ZrSi2 particles on pyrolytic products of foam composites was also analyzed.The results show that the introduction of ZrSi2 particles does not affect the curing and crosslinking of boron-modified phenolic resin but induces chemical reactions with pyrolytic volatiles derived from bo-ron-modified phenolic resin,which could increase the char yield and the compressive specific strength of pyrolytic products.When the mass ratio of introduced ZrSi2 particles to boron-modified phenolic reaches 10%,there is the most significant improvement on the char yield and the compressive strength of pyrolytic products.After pyrolysis of ZrSi2/boron-modified phenolic foam,ZrSi2 particles are pinned on the cell walls of pyrolytic products as the sec-ondary phase particles,part of pyrolytic volatiles are absorbed and translated into solid phase products by chemical reaction,and obviously decreased defects increase the mechanical property of pyrolytic products.