Study On Synthesis Of Phenolic Resin With Low Free Formaldehyde Content, Phenol And Modified By Urea

With the enhancement of environmental protection consciousness, people put forward higher requirements on the phenolic resin. Although the phenolic resin itself has a good overall performance, but in practical application, the actual effect is not very ideal, an important reason is the resin of free phenol and free formaldehyde content is too high, great harm to the people and the natural environment, but also on the resin can have an impact, therefore, the synthesis of low free phenol free formaldehyde and high residual carbon content of phenolic resin in line with the current development trend of phenolic resin of the whole industry, will also become the focus of current research.In this paper, the high flame retardant polystyrene foam insulation board with thermosetting phenolic resin matrix synthesis route, reaction conditions optimization and modification technology research, designed to ensure a higher amount of carbon residue and on the basis of the comprehensive performance of reduce the free phenol, the free formaldehyde content.The research mainly through the method for determination of free phenol content, free formaldehyde content, viscosity and solid content of resin activity, such as physical and chemical indicators, the synthesis conditions of phenolic resin, effect of reaction temperature, dosage of catalyst, F/P molar ratio and reaction time on the properties of resin, Without considering the interaction design based on the L9(34) orthogonal test to determine the formulation of the synthesis of phenolic resin. Analysis showed that the optimum reaction conditions were: reaction temperature 85 degrees, F/P molar ratio 1.3, reaction time was 2.5 hours, the dosage of catalyst 5 grams, the vacuum degree is 0.08~0.093 MPa, 3~4 hours after vacuum distillation, the solid content of the measured resin 76~89%, the viscosity is 2500~3500mPa·s, the free phenol content was 4.53%, hydroxymethyl content was 37.237%; by means of Fourier transform infrared spectroscopy and 13 C nuclear magnetic resonance according to the analysis of the structure of the resin, thermosetting phenolic resin synthesized with high ortho substituted structure, fast curing speed of 3~4 times than general phenol formaldehyde resin; The thermogravimetric analysis results indicated that the amount of residual carbon, phenolic resin synthesis was 43.3%.Based on the research on properties of phenolic resin on flame retardant, the residues of harmful substances content is higher the higher cost of product defects, its production process, this paper studied the modified urea on it. This modified test of formaldehyde in two batches will be added to the reaction system, the research mainly by the F1/P molar ratio, F2/U molar ratio, catalyst amount, reaction temperature and reaction time on percentage of modified phenolic resin by physical-chemical properties, the study found that, the addition of urea phenol formaldehyde resin, not only reduces the cost, urea formaldehyde and can be used as curing agents, decrease the free formaldehyde content in the modified resin product of; by infrared spectrum and nuclear magnetic resonance analysis, with the urea modified phenolic resin containing the active groups of hydroxymethyl phenol, and ring and methylol urea connected mainly by the methylene, At the same time, success will be N element is introduced into the phenolic resin, that is based on-Ph-CH2-N- and-N-CH2-N- structure, the improvement of the flame retardancy of phenolic resin was also help.