Studies On Synergistic Flame Retardant Effect Of Hydrated Magnesium Hydroxide/Red Phosphorus For NR/LLDPE TPV

The dynamilly vulcanized NR/LLDPE blnded thermoplastic elastomer (TPV) has been studied in the dynamic vulcanization technology condition, the adding means of nano-silica and the mass of nano-silica by analyzing mechanical properties. The effects to mechanical properties and flame-retardant cases of NR/LLDPE TPV, Which is added magnesium hydroxide,red phosphorus and manesium hydroxide/red phosphorus compound flame retardant, were investigated by the surface modification agents and GMA/St/DCP multi-monomer "in situ" grafting. The properties and the structure of TPV were investigated by SEM, DMA, TG, DTG and LOI.The study of dynamic vulcanization technology on NR/LLDPE TPV showed that the best NR/LLDPE ratio is 60/40, the best dynamic vulcanizing temperature,dynamic vulcanizing time,moldpressing pressure and moldpressing time is 130℃,6min,17Mpa and 8min, while the mass ratio of nano-siliea is 0.03.The study on flame-retarded NR/LLDPE TPV, showed that Mg (OH) 2/red phosphorus flame retardant compound of the TPV has a good synergism effect of flame retardant. The mechanical properties and flame-retardant cases of TPV is advanced significantly when the manesium hydroxide and red phosphorus were surface-coupled by different coupling agent, KH-550 is the best coupling agent of the three. GMA/St/DCP multi-monomer "in situ" grafting system increase is an effective way to modify the flame retardant compound. Comparison with NR/LLDPE TPV, the conservation rate of the tensile strength and tear strength of GMA/St/DCP multi-monomer "in situ" grafting manesium hydroxide/red phosphorus compound (which are modified by KH-550) flame-retarded TPV is 82.80% and 98.36%. The flame-retarded TPV had a good smoke suppression effect and no melt driping phenomenon when it is burning, and the LOI was 25.6, flammability of the TPV material also reached UL94V-1 level. The Storage modulus(E') GMA/St/DCP multi-monomer "in situ" grafting manesium hydroxide/red phosphorus compound (which are modified by KH-550) flame-retarded TPV is lower, and it has small Tg, a lower tanδat Tg and a high tan 8 in High-elastic states, so the material has a better resistance to cold, lower temperature impact resistance and high temperature defomation. The experimental results indicated that manesium hydroxide/red phosphorus compound (which are modified by KH-550) flame-retarded TPV modified by GMA/St/DCP multi-monomer "in situ" grafting, manesium hydroxide and red phosphorus could be uniformly dispersed in NR and LLDPE matrix and possessed good interfacial combination, while the NR and LLDPE matrix would be possessed good interfacial combination also. The destruction of TPV was mainly the LLDPE matrix becoming deformed and the NR phase pulled out from the matrix instead of the defect of flame retardant particles's reunite and the weak interface of flame retardant particles and polymer material.