Study On The Flame Retardant Properties Of Thermoplastic Polyolefin Elastomer Waterproofing Membrane

Thermoplastic polyolefin elastomer(TPO)waterproof membrane is a thin sheet of thermoplastic building waterproof material,which is made of advanced chemical synthetic material technology and specific chemical formula technology.A new building waterproof material.Although TPO waterproofing membrane is a copolymer of polypropylene and polyethylene,it is not simply a mixed copolymerization of the two,but a continuous phase of a copolymer that is uniformly and closely distributed,and has both excellent properties.This makes not only TPO has very good ductility,but also excellent waterproof performance is the most important performance of TPO.However,TPO waterproof membranes are very easy to burn,and the fires caused may have serious life and economic impacts on social and public safety,restricting the current widespread application of TPO waterproof membranes.There are many types of flame retardants.When selecting flame retardants,halogen-free flame retardants and environmentally friendly flame retardants are first considered.Phosphorus flame retardants and intumescent flame retardants are two commonly used halogen-free flame retardants with high flame retardant efficiency.However,TPO material is a kind of polyolefin composite material that is more difficult to achieve flame retardant,so the amount of these flame retardants added will be relatively large,which makes the compatibility of the added flame retardant with the TPO matrix become very If it is poor,the mechanical properties of the flame retardant TPO material will also deteriorate.At the same time,due to the strong hydrophilicity of the flame retardant,it also has a great impact on the TPO's original excellent waterproof performance.This article first explores the effect of different flame retardants on the flame retardant properties of TPO,and at the same time compares the mechanical properties and water resistance of flame retardant TPO.A flame retardant with better flame retardant efficiency is selected to modify it to improve the water resistance and mechanical properties of flame retardant TPO.The main research contents are as follows:1.Choose red phosphorus(RP),pentaerythritol phosphate(PEPA)/melamine ammonium polyphosphate(MPP),ammonium polyphosphate(APP)/triazine-based carbon-forming agent(CFA)and phosphorus nitrogen flame retardant FP2200S The flame retardant treatment of TPO materials by different flame retardant systems,and the flame retardant effects of four flame retardant systems on TPO materials are studied.The results show that these four flame retardant systems have good fire retardant effects on TPO materials.When it is necessary to make the TPO material reach the same flame retardant standard,the addition amount of the four flame retardant systems is 15wt%,20wt%,10wt%and 20wt%,respectively.The mass fraction is closely related.The more mass fractions added,the greater the percentage of decrease in mechanical properties.2.The silane coupling agent KH550 is grafted on the structure of the flame retardant PEPA,and the modified product Si-PEPA and the carbon forming agent MPP are compounded in a mass ratio of 4:1 and added to the TPO matrix Conduct flame retardant research.The results show that the modified TPO/Si-PEPA/MPP material has a vertical combustion level increased from no level(NR)to V0 level,and the oxygen index LOI value is from 29.6%Increased to 32.2%,the pHRR and THR of the modified material in the cone calorimeter test were reduced from 343 kW/m2 and 113 MJ/m2 before modification to 246 kW/m2 and 95 MJ/m2,respectively The thermal stability of the material is greatly improved,and the mechanical properties of the modified TPO/Si-PEPA/MPP material are also improved.And the water absorption rate of TPO composite material with 20 parts of flame retardant immersed in hot water at 70? for 168h was reduced from 9.6%to 7.4%.3.Four different polysiloxanes were used to synthesize a silicone resin with a larger molecular structure to coat APP and CFA at a mass ratio of 3:1 at the same time to microencapsulate to reduce the hydrophilicity of these two flame retardants.After the product Si-IFR is obtained,the TPO material is directly flame-retardant.The results show that the water contact angle of Si-IFR is increased from 0° to 140° of IFR.The modified TPO/Si-IFR material has a water absorption rate of 9.21%after being immersed in hot water at 70? for 168h.Reduced to 7.02%,and the flame retardant performance of TPO/Si-IFR material before and after the water resistance test can reach the V0 level of the vertical combustion test.In the cone calorimetry test,the pHRR and THR are respectively from 426 kW m2 and 108 MJ/m2 are reduced to 313 kW/m2 and 106 MJ/m2,and the modified TPO/Si-IFR material has better mechanical properties,and its tensile strength is increased from 10.3MPa to 11.3MPa.