摘要
本文采用扭辫分析技术研究了不同表面状态的芳纤/环氧复合材料的固化过程。根据一系列等温固化谱图和热机谱图,得到时间-温度-转变(T、T、T)状态图,此图可以用来指导复合材料的复合工艺制订。依照固化温度,得到三类固化行为:(Ⅰ)T_(固化)<T_(gg)时,仅有玻璃化作用,(Ⅱ)T_(gg)<T_(固化)<T_(g∞),则有凝胶作用和玻璃化作用,(Ⅲ)T_(g∞)<T_(固化)时,仅有凝胶化作用。 文中还测定了不同固化反应体系的化学反应级数、反应速率、活化能等化学动力学参数,并讨论了不同芳纤表面状态对复合材料固化反应动力学参数的影响和对复合材料成品热机性能的影响。
Based on. the curing temperature, three types of behavior of various surface characterized PPTA fiber/epoxy systems were observed:(Ⅰ) below Tgg (the glass transition temperature of the reaction systems at the gel point) only vitrification come about;(Ⅱ) between Tgg and Tg∞ (the gla-ss transition temperature of the ultimately cured polymers)both gelatini-zation and vitrification come about, and (Ⅲ) above Tg∞, only gelatini-zation takes place.Overall activation energies and apparent overall rate constant of the curing reactions for various surface characterized PPTA fiber/epoxy sys-tems based on third-order overall kinetics were determined before gela-tion, after gelation but before vitrification and after vitrification, from the gelation time, relative rigidity and glass transion temperature Tg(t) of the polymers as the.kinetic terms. The influence of. the curing tempera-ture and surface property of the fibers on the kinetic parameters is dis-cussed. Based on various relative rigidity and damping curves vs. time under isothermal conditions, we obtained Time-Temperature-Transition(T.T.T.) state diagrams of various surface characterized PPTA. fiber/epoxy sys-tems.These state digrams (T.T.T.)can be used in formulating the curing technology for various kinds of fiber reinforced epoxy composites.
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
1991年第1期13-20,共8页
Acta Materiae Compositae Sinica
关键词
芳纶纤维
固化动力学
三T状态图
curing behavior, surface of aromatic polyamid fiber, three -T state diagram, curing kinetics, torsion braid analysis
