Study On The Preparation And Properties Of Polypropylene Composites Reinforced By Carbon Fiber

Carbon fiber?CF?is a kind of inorganic fiber,which is lighter,thinner and strengthener than the glass fiber,and has become increasingly popular recent years because of the improving of its production technology.When using CF for reinforcing PP resin to preparaing the PP/CF composites,the mechanical properties of material was improving significantly and maintaining the low-density level.However,on the one hand,because of the enhancement effect of the CF is affected by the nature of itself and the resin,it is needed to be properly processed to ensure a better work.On the other hand,the addition of CF will further deteriorate the flammable and the molten dripping properties of the composite,which made they must be modified by flame retardant before actually using.First,the CF reinforced thermoplastic composites was prepared by PP and the nitric acid oxide short carbon fiber?NCF₁?,or the nitric acid oxide carbon fiber powder?NCF₂?,which was modified by wet chemical method before using.The relationship among the surface property,aspect ratio,content of vary types of carbon fiber and the properties of PP/CF composites was been investigated.The results indicated that the composites achieved the better synthesis mechanical properties when reinforced by the NCF with higher aspect when the content of CF in composites is reasonable.The best contents of NCF₁ in composites is ranged from 10%to 20%,and when the amount of NCF₁ is 15%,the tensile strength,bending strength and notched impact strength of PP/NCF₁ composites were 59.4MPa,93.8MPa and 6.9kJ/m2,which was 93.3%,114%and 60.5%higher than that of neat PP.The best contents of NCF₂ in composites is ranged from 5%to 15%,and when the amount of NCF₂ is 15%,the tensile strength,bending strength and notched impact strength of PP/NCF₂ composites were improved to that of neat PP's 112.8%,118.5%and 127.9%.The addition of CF decreased the crystallinity and processing properties of composites,and shows no obviously effect on the melt temperature and crystalline temperature of composites.The flame retardant modification of PP/NCF₂ composites with the Brominated flame retardant FR8000,Intumescent flame retardant IFR and CS-IFR were studied.The results show that all these kinds of flame retardant mentioned were able to improving the flame retardant performance and the thermal stability of composites.When the content of FR8000 in composites was 3phr,the LOI of composites was improving to 32.1%,the flame retardant level was V-2,but still with molten dropping.Meanwhile,the addition of FR8000 damaged the Notch Impact Strength but promoted the processing properties of system lightly.When the contents of CS-IFR in composites was 24phr,the LOI of system promoted to 28.9%,the flame retardant level was V-0,the molten dropping performance was been depressed,the mechanical properties and the processing properties were been decreased.