Preparation And Properties Of Flame-retardant RPUF Of MATH Synergistic Intumescent Compound System

In recent years,the production and sales of my nation’s rigid polyurethane foam(RPUF)have continued to grow rapidly.Under the guidance of the national policy "Industrial Structure Adjustment Guidance Catalog(2019)",it is necessary to highly develop green flame retardants and improve the flame retardancy of RPUF.Intumescent flame retardants are divided into two types:chemical intumescence and physical intumescence.Because of their high flame retardant efficiency and green environmental protection,they have become current research hotspots.There are two main problems in the application process that need to be solved urgently:on the one hand,they contain organic bases.Although the chemical intumescent flame retardant of the group has good compatibility with the polymer matrix and has little effect on the physical structure and mechanical properties of RPUF,it is complicated to prepare and expensive;on the other hand,for physical intumescent flame retardants,it can be Although expanded graphite(EG)has low cost and excellent flame retardant properties,the compatibility of inorganic flaky EG with polyurethane matrix is poor,which seriously deteriorates the physical structure and mechanical properties of RPUF.In order to solve these two problems,this paper combines the above two into a compound system,and uses alkylated modified aluminum hydroxide(MATH)and its synergy for flame-retardant RPUF.The main research contents are as follows:(1)A chemical intumescent flame retardant was synthesized by reacting 3-hydroxyphenylphosphoryl-propionic acid(CEPPA)with melamine(MA)in an aqueous solution:3-hydroxyphenylphosphorylpropionic acid melamine salt(CMA),and It is compounded with ammonium polyphosphate(APP)as the flame retardant of RPUF.Different RPUF samples were prepared by the one-step foaming method,and the physical structure,mechanical properties,and thermal decomposition properties of the RPUF of the composite system were studied by means of thermal weight loss analysis,smoke density analysis,combustion performance testing,and scanning electron microscope(SEM).And the influence of flame retardant properties,reveals the flame retardant mechanism of gas phase and condensed phase.The results show that CMA has very little effect on the physical structure and mechanical properties of RPUF.When the mass fraction ratio of APP is 1:1,the mechanical properties of RPUF/10%CMA/10%APP are the best,and the LOI of the pure sample is improved by 35.4%,the compound system has both gas phase and condensed phase flame retardant effects,which can significantly improve the flame retardant performance of RPUF.(2)APP was modified by the silane coupling agent APTES to synthesize MAPP,which was characterized by scanning electron microscopy,Fourier infrared spectroscopy,XPS and other testing methods.And it was compounded with expandable graphite(EG)as a flame retardant,and flame retardant RPUF samples were prepared under laboratory conditions,and the cell structure,mechanical properties,oxygen index,smoke density,thermal properties and flame retardant properties were studied.The results show that when the mass ratio of EG to MAPP is 3:1,the two have a good synergistic effect.The physical structure and mechanical properties of the sample RPUF/15%EG/5%MAPP are better,and the maximum LOI is 36%.Compared with pure RPUF,it is increased by 16.8 units,and the combustion behavior parameters HRR,THR,FIGRA,EHC are the lowest.It not only has the physical barrier of EG heating to form an expanded carbon layer,but also the gas and condensed phase flame retardant effects of MAPP pyrolysis.The best overall performance.(3)Surface treatment of aluminum hydroxide(ATH)with silane coupling agent KH550 to obtain MATH,and its structure and performance were characterized by FT-IR,SEM,XPS,TG/DTG and other test methods.Subsequently,MATH was used as a flame retardant synergist with smoke suppressant and expansion system CME(CMA/MAPP/EG)to prepare polyurethane rigid foam samples.The synergy between the two was discussed,and the physical structure,mechanical properties,and mechanical properties of the flame retardant on RPUF were studied.The influence of oxygen index,thermal performance,smoke density and flame retardant performance.The results show that:MATH,as a synergist and smoke suppressant,is compounded with the expansion system CME,and can have a synergistic effect at a mass ratio of 1:9.The physical structure and mechanical properties of the sample RPUF/2%MATH/18%CME Better,the LOI is 77.6%higher than pure RPUF,and the combustion behavior parameters HRR,THR,FIGRA,EHC are all minimized,so that the sample has both good physical properties and excellent flame retardant and smoke suppression properties.