Effect of aramid fibers on properties of EPDM-based flame retardant composites
Using ethylene-propylene diene monomer(EPDM)as the matrix,the influence of the dosage of aramid fiber(AF)and phosphoric acid,y-aminopropyl triethoxylsilane(KH550)modified aramid fiber(AF-P-Si)on the properties of EPDM matrix composite was investigated.The results show that when the amount of AF is 1~5 phr,the scorch time of EPDM compounds does not change much;when the amount of AF exceeds 3 phr,the curing extent increases.With the increase of AF content,the tensile strength and elongation at break of EPDM vulcanizates decrease,while the hardness,tear strength,abrasion resistance and thermal oxygen aging performance gradually increase.Especially when the AF content is 3 or 5phr,the modulus at 100%elongation of EPDM composites improves significantly.For AF-P-Si,it is beneficial to improve the hardness,tensile strength,elongation at break and tear strength of the EPDM composite.According to cone calorimeter results,the EPDM vulcanizates filled with 3~5phr AF obtain high fire performance index(FPI),while modified AF reflects a better flame retardant effect.