Study On New Synthetic Process And Stability Of Light Coloured Rosin Modified Phenolic Resin

Based on the rich forest resources of rosin as raw material in Guangxi,this article carried out the research of new synthetic process to synthetise light coloured rosin modified phenolic resin,and explored the factors for affecting the stability of product.The main research contents and achievements followed:(1)Explored the colour change rule in the rosin melting process,and put forward the method to control the colour.By means of various factors to the research on the influence of oxidation reaction in the rosin melting process,we found that it could reduce rosin melting colour after the reaction system was exhausted oxygen.Using the vacuum to exhaust oxygen was better than using the nitrogen to exhaust oxygen.The purity and flow of nitrogen could bring the influence for the colour,the greater nitrogen was exhausted,and the lower nitrogen purity was used,the deeper colour of rosin was changed.(2)Built the quantitative analysis method in the reaction system of rosin and phenolic resin.By means of exploring the absorption characteristic and the first derivative characteristic of rosin,phenolic resin,rosin modified phenolic resin and their mixture.We found that it could eliminate distractions for rosin absorbance by using the first derivative method,thus we established the quantitative analysis method of track reaction process.The quantitative analysis equation was the first derivative absolute value of rosin absorbance Y and molarity C,Y=0.00092C+0.0009(C was 0.50×10-5 mol·L-1?5.0×10-5 mol·L-1).The recovery rate of the range was 97.05%?101.33%,the relative standard deviations of precision,stability and recovery rate were 3.37%,2.60%and 2.36%.(3)Studied on the new synthetic process of light coloured rosin modified phenolic resin.By means of analyzing the technological characteristic of "two step method" to synthetise rosin modified phenolic resin and the key factors influencing the colour of product.We put forward the new technology that the oxygen was exhausted when it was in the rosin melting process,the condensed liquid of phenolic resin and the glycerinum.The performance indicators of rosin modified phenolic resin followed,the colour gradation(using the improved linseed oil method):<8,the softening point:160??170?,the acid value:<25 mgKOH·g-1,the viscosity:67"?90".(4)Put forward the improved iron cobalt method that measured the colour of rosin modified phenolic resin.The experiment pointed out that the iron cobalt method couldn't dissolve well rosin modified phenolic resin when it used toluene as solvent.We put forward the improved iron cobalt method after exploring by a lot of experiment,the proportion of resin,toluene and ethanol was 1:0.8:0.2(mass ratio),using this method could solve the problem that the solution was not clear.(5)Put forward the improved linseed oil method that measured the colour of rosin modified phenolic resin.This method was that the resin used nitrogen protection in the melting process,using this method could solve the problem that the colour of product was instability and deep in the heating process.(6)Carried out the study on the thermostability of rosin modified phenolic resin and stability method.By means of the experiment explored in the airtight reserve of nitrogen gas,the airtight reserve of frozen gas,the airtight reserve of vacuum,the reserve of open air and the reserve of adding the antioxidants.We found that they not only could extend the storage period of product,but also could improve the stability of product in the reserve of frozen gas,the reserve of vacuum and the reserve of adding the antioxidants.