Study On New Toughening Flame Retardant Polycarbonate

Because of excellent mechanical properties, flame-retardent and good processability, polycarbonate gets a wide range of application. However, some properties of PC still can't reach the requirment of practical application, such as low impact-resistent, low efficiency of flame retardants etc.. In order to improve impact-resistent and achieve flame-resistant purpose, PC were modified by adding new toughening reagents and green flame retardants. And several kinds of modificated PC with excellent properties were made.Firstly, two kinds of toughening reagents POE-g-MAH and(POE/PP/MBS)-g-MAH) with similar liquidity and MAH grafted rate were made. PC and toughening reagents were directly blended and the effects of different contents of toughening reagents on mechanical properties were investigated. Research shows:as increasing of toughening reagents, PC's tensile strength, bending strength and bending modulus is decreased, but tensile elongation is increased. Compared with the toughening effect of POE-g-MAH, (POE/PP/MBS)-g-MAH's is better. It is because MMA in MBS increases compatibility of the PC alloy. And 5% to 10% of (POE/PP/MBS)-g-MAH is suggested.Secondly, oxygen index number method and perpendicular burnable method were used to investigate the influence of several kinds of flame retardants on flame-resistant properties of PC. Research shows:adding contents of aluminum hydroxide and magnesium hydroxide are huge, and physical and mechanical properties of the modified PC are deteriorated; flame retardent of PC is increased from UL94-V2 to UL94-V0 by adding 6 parts of FR-Br, and strength of PC is increased too; flame retardent of PC is increased from UL94-V2 to UL94-V1 by adding 6 parts of FR-Si, and has few influence on system properties.Finally, the influence of the main compositions in the system and other conditions on the mechanics property of the composites was investigated:silicone oil can improve the flame retardant effects of FR-Si, but also can greatly reduce the tensile elongation at break; FR-Si modified PC is sensitive to temperature, there are lots of cavities in the fracture surface of the PC if the processing temperature is too high.