Flame Retardantion Of The Water Borne Intumescent Fire Retardant Varnish

Based on the water borne intumescent fire retardant varnish (WBIFRV) that was madefrom curing agent and melamine urea formaldehyde resin (MUF), this paper explored itsflame retardant mechanism by investigating: the influence of the introduce of pentaerythritol(PT), epoxy resin E-51(E-51) and1,4—butanediol diglycidyl ether (BDE) of curing agenton the flame retardancy vanish films; the influence of melamine urea formaldehyde resin(MUF) degree of polycondensation and the ratio between phosphate resin acid（PRA）MUFon the flame retardancy vanish films;the effects of Neopentylglycol(NPG),trimethylolpropane (TMP) and Pentaerythritol (PT) that used as etherifying agent on theflame retardancy of varnish films.the main experimental results are as follows:1) The heat-release amount and the thermal barrier property of the char layer formed byheating varnish films were determinants of varnish film’s fire retardancy. Below500°C, theintumescent degree was the major determinant of the char layer’s thermal barrier property.The greater intumescent degree, the better the thermal barrier property was. Above500°C, theclosure and compactness were determinants of the layer’s thermal barrier property. The moreclosed and compact the char layer was, the more effective its thermal barrier property was.2) PT, E-51and BDE could influence the thermal barrier property of the char layer byaffecting its intumescent degree,compactness and closure; the flame retardancy test, scanningelectronic microscopy (SEM) and thermal analysis showed that PT and E-51contributed thegreater intumescent degree and compactness of char layer;PT is benificial for the closure ofchar residue at high temperature,but increased the heat release. BDE contributed the closedbuble structure of the char layer, while decreased the heat release and intumescent degree.3) MUF polycondensation degree and PRA/MUF radio could influence the thermalbarrier property of the char layer by affecting its intumescent degree,compactness andclosure;the flame retardancy test, scanning electronic microscopy (SEM) and thermal analysisshowed that Higher polycondensation degree of MUF corresponded to more heat-releaseduring degradation, and excessively high or low MUF solid content would increase theintumescent degree but detrimental to the closure of the char layer. PRA/MUF ratio hardlyaffected intumescent degree; appropriately raising the PRA/MUF ratio could make the charlayer more compact and closed, and decrease heat release during degradation; but excessively high PRA/MUF ratio could worsen the closure of the char layer, and increase heat releaseduring degradation.4) The introduce of polyhydric alcohols of MUF is beneficial to improve intumescentdegree,compactness and the buble uniformity of char layer,and the improvement ofintumescent degree,compactness and the buble uniformity is beneficial for the charlayer’s thermal barrier property;polyhydric alcohols are carbon source,the introduce of carbonsource could increase heat release,but the better thermal barrier property is beneficial todecrease heat release...