固化反应对单向碳纤维预浸料介电性能的影响OA

The curing of carbon fiber reinforced polymer(CFRP)via microwave heating has the advantages of energy reservation and consumption reduction,but microwave curing technology still faces the limitation of hard to control on the heating process.A cylindrical cavity perturbation measurement method is utilized to study the effect of curing reaction on the complex dielectric permittivity of unidirectional carbon fiber prepregs in depth.By taking the dynamic DSC scan on the uncured prepreg in the temperature range from-50～300 ℃,the Tg,0 of un-cured prepreg is determined to be-13.8 ℃.The rheological testing indicates that the resin matrix is in sol state at room temperature,and the sol-gel transition occurs after 51 min of curing.The dynamic mechanical analysis testing demonstrates that the resin matrix begins to undergo glass transition after 73 minutes.The dielectric properties anal-ysis indicates that the axial dielectric constant ε'r of the prepreg fluctuates between 120.2 and 127.3 throughout the curing process.The dielectric loss εe″ff maintains at 0.63 in the first 55 minutes of the curing process.It decreases to 0.52 due to the sol-gel transition after curing for 60 minutes,and increases to 1.4 due to the glass transition from 75 to 90 minutes.The εe″ff of the fully cured prepreg finally decreases to 0.72 and remains stable.The study provides data support for quantifying the microwave energy absorption and conversion of CFRP,which is beneficial for im-proving the precise control of CFRP microwave heating.