摘要
分别以亲水型A200和疏水型R805两种纳米SiO2为增强剂,采用超声分散/高速剪切法,制备出纳米SiO2改性酚醛泡沫,对比了它们的泡体结构、压缩性能和热稳定性的差异。实验结果表明,两种纳米SiO2颗粒的化学结构基本相同,但R805纳米SiO2颗粒的表面接有含烷基的疏水层。当A200纳米SiO2质量分数分别为1.5%和1.0%时,改性酚醛泡沫的压缩强度和压缩模量达到最大值;R805纳米SiO2改性酚醛泡沫的压缩强度和压缩模量均下降。两者的初始热分解温度和残碳量均有一定程度的提高,但前者的初始分解温度较高,而后者的最终残碳量较多。改性酚醛泡沫的泡体结构、纳米SiO2与酚醛的界面结合优劣,对其压缩性能和热稳定性的增强起到了重要作用。
Two kinds of phenolic foam modified with hydrophilic nano - SiO2 （A200） and hydrophobic nano- SiO2 （R805） as reinforcing agents, both with average 12 nm in diameter, were prepared by ultrasonic dispersion and high - speed sheafing. Their differences in cell structures, compressive properties and thermal stabilities were compared. FTIR analysis shows that the chemical structures of both nano - SiO2 are similar but the hydrophobic layer of alkyl groups is attached to the surface of nano - SiO2 （ R805 ）, Compressive modulus and compressive strength of modified phenolic foam reach the optimum as mass fraction of nano - SiO2 （A200） are 1.5% and 1.0%, respectively. However, compressive modulus and compressive strength of phenolic foam modified with hydrophobic nano- SiO2 （R805） reduce sharply. The initial decomposition temperatures and carbon residual amounts of both increase to a certain extent, but initial decomposition temperature raising of former is more and on the contrary the ultimate carbon residual increment of the latter is more. According to SEM and TG analysis, the improvement of compressive properties and thermal stability are largely due to the modification of cell structures and interface bonding of nano - SiO2 particles with phenolic groups.
出处
《石油化工》
EI
CAS
CSCD
北大核心
2007年第12期1266-1270,共5页
Petrochemical Technology
基金
上海市科技发展基金项目(06DZ22012)
上海市重点学科建设项目(B113)
关键词
纳米二氧化硅
酚醛泡沫
压缩性能
热稳定性
界面
nano - silicon dioxide
phenolic foam
compressive property
thermal stability
interface
