玻纤增强聚酰胺6/次磷酸钆复合材料的制备及其阻燃性能

Preparation of Glass Fiber Reinforced Polyamide 6/Gadolinium Hypophosphite Composite and Flame Retardant Properties

以共沉淀法将六水合氯化钆(GdCl_(3)·6H_(2)O)和次磷酸钠(NaH_(2)PO_(2))混合制备得到一种新型稀土金属次磷酸盐-次磷酸钆(GdHP),采用熔融共混法制备系列玻纤增强聚酰胺6/次磷酸钆复合材料(GFPA/GdHP),并利用极限氧指数、UL94垂直燃烧、热重-热失重、微型量热等测试分析GdHP对GFPA的阻燃作用。结果表明,当GFPA添加量为20%时,GFPA/GdHP20复合材料的极限氧指数可以达到26.5%,垂直燃烧可以达到V-1级别;GFPA/GdHP20复合材料的T-5%值和Tmax值分别下降至354℃和408℃,在700℃时,残炭率增大至51.6%;PHRR值与THR值分别下降40.8%及27.5%;扫描电镜结果表明,GdHP能明显提高GFPA/GdHP复合材料炭层的致密程度,从而抑制燃烧区域内氧气、热解产物及热量的交换,能有效地提高GFPA/GdHP复合材料的阻燃性能。

A novel rare earth hypophosphite—gadolinium hypophosphite(GdHP)was synthesized by co-precipitation method using gadolinium chloride hexahydrate(GdCl_(3)·6H_(2)O)and sodium hypophosphite(NaH_(2)P0_(2))as raw materials.GdHP was used as flame retardant to prepare a series of glass fiber reinforced polyamide 6/gadolinium hypophosphite composites(GFPA/GdHP)by melting bending method.Limiting oxygen index(LOI)test,UL 94 vertical burning experiment,thermogravimetric test,microscale combustion calorimetry(MCC)were used to analyze the flame retardant effect of GdHP on GFPA.The results showed that the LOI of the GFPA/GdHP20(with 20%GdHP)reached 26.5%,and the vertical combustion reached UL 94 V-1.T_(5%)and T_(max) of GFPA/GdHP20 composite were decreased to 354℃ and 408℃,respectively.The carbon retention rate at 700℃ of GFPA/GdHP20 composite was increased to 51.6%.PHRR and THR of GFPA/GdHP20 composite were decreased by 40.8%and 27.5%compared with GFPA.SEM showed GdHP could significantly increase the density of the carbon layer of the GFPA/GdHP composite,thereby inhibiting the exchange of oxygen,pyrolysis products and heat in the combustion area,and effectively improve the flame retardant properties of GFPA/GdHP composite materials.