Study On Flame Retardant Properties Of Poly (L-Lactic Acid) Composites

Poly(L-lactic acid)(PLA)is one of environmentally friendly and completely biodegradable polymer materials.Poly(L-lactic acid)belongs to flammable materials with severely dripping,inhibited the development of polylactic acid.In this thesis,the flame retardant property of poly(L-lactic acid)was inproved by the method of melt blending.The detailed content as follows:A crosslinked silicone-containing macromolecular agent(CSi-MCA)was synthesized via “one-pot” method.Cyanuric chloride was used as raw materials,then silane coupling agent(KH540)and ethylenediamine were added.The reaction was controlled by adjusting the temperature and pH.The synthesized CSi-MCA was characterized by fourier transform infrared spectroscopy(FTIR),solid-state 13 C nuclear magnetic resonance(13C-NMR).Thermal gravimetric analysis showed that the capacity of formed char.The synthesized CSi-MCA was combined with ammonium phosphate(APP)to prepare PLA composites,and influence of their ratio on the flame retardance of PLA was investigated.The flame ratardance was evaluated by the limiting oxygen index(LOI),vertical combustion rating(UL-94)and cone calorimeter test(CCT).When the content of CSi-MCA was 5wt% and APP was 10wt%(CSi-MCA/APP=1/2),the flame retardant properties of PLA is best,but there would still be dripping.In order to solve the problem of dripping,silica or nickel oxidewere added to the PLA/CSi-MCA/APP system.The materials were characterized by LOI,UL-94,CCT.When adding a small amount of nickel oxide to the PLA/CSi-MCA/APP system,the dripping phenomenon was obviously inhibited.Moreover,when the content of silica was 1wt%,there was no dripping,and its flame retardancy was further improved.