预分散酚醛中空微球对三元乙丙橡胶绝热层性能的影响及梯度化绝热层的研究

Effects of pre-dispersed hollow phenolic micro-spheres on properties of EPDM thermal insulator and study on functionally graded thermal insulator

分别制备了预分散酚醛中空微球填充三元乙丙橡胶绝热层和梯度化三元乙丙橡胶绝热层,旨在开发低密度的新型高性能绝热材料。扫描电镜观察表明,预分散酚醛中空微球能完好、均匀地分散于三元乙丙橡胶基体中。由于酚醛中空微球具有很低的粒子密度和高的热阻性能,随预分散酚醛中空微球含量的增加,绝热层的密度、热导率和热扩散率显著降低,同时绝热层的比热容明显增大,表现出优异的绝热性能。与芳砜纶浆粕填充三元乙丙橡胶绝热层、酚醛中空微球填充三元乙丙橡胶绝热层相比,梯度化三元乙丙橡胶绝热层具有优异的绝热性能和耐烧蚀性能,同时又具有很低的密度,将在火箭发动机上具有广阔的应用前景。

Ethylene-propylene-diene elastomer （EPDM） thermal insulator filled with pre-dispersed hollow phenolic micro- spheres and functionally graded EPDM thermal insulator were prepared as high performance thermal insulating materials with low density. Experimental results show that the pre-dispersed micro-spheres in the EPDM matrix are undamaged and homogeneous dis- persed, which was observed with scanning electron microscopy （SEM）. With the increase of the content of the pre-dispersed hollow phenolic micro-sphere, the density, thermal conductivity and thermal diffusivity of EPDM thermal insulator decrease linearly and specific heat of the insulator increase greatly, owing to the low particle density and high thermal resistance of hollow phenolic micro- spheres. Compared to both thermal insulators filled with hollow phenolic micro-spheres and pelysulfonamide （PSA） pulp, function- ally graded thermal insulator show excellent thermal insulating and ablation properties as well as very low density, exhibiting an ap- plication potential as high performance thermal insulator in advanced rocket motors.