Study On Ester Cured Phenolic Resin System For Modeling

At present, to develop a new binder with high-quality, top efficiency, energy saving, environmental protection is the urgent need for the development of the green foundry. In this context, a new type of organic ester cured alkaline phenolic resin process was introduced by the company, which is Foseco that belongs to the United Kingdom in 1989.Compared with acid cured furan resin, it has obvious advantages:low content of toxic components, low environmental pollution, simple cured process, high production efficiency, etc. And at the same time, this process has its manifest disadvantages:low resin strength at common temperature, high viscosity, high content of free formaldehyde, short shelf life, as well as recycling difficulties of used sand. Because of the above-mentioned characteristics of phenolic resin, for decades, both endless love on the phenolic resin sand, and worry about it constantly by foundry workers. Phenolic resin sand costs are high, so it used less, but used more by English. In recent years, there is an increasing trend on its application in our country. Continuing to overcome the shortcomings, at the same time, alkaline phenolic resin sand process has also been continuously improved and enhanced, so it is to become hope of green cast in the 21st century.In this paper, just for problems of alkaline phenolic resin in casting production, four tasks were made as follows:Firstly, In terms of two-step synthesis technique of alkali added, with the aid of a single factor experiments various factors affecting the performance of alkaline phenolic resin were studied, that is, the molar ratio of phenol and formaldehyde, feeding method, the type of catalysts and its dosage, before and after adding the ratio of alkali and reaction viscosity, and the optimum condition of synthesizing ester cured alkaline phenolic resin was derived. Secondly, for the special case of the best processing conditions, the research synthesis process was modified, which includes a substitute for phenol (bisphenol A, a variety of p-cresol), modifiers (acetone, iso-propanol). Through these areas before and after the performance of phenolic resin of the synthesis of modified was discuss. Thirdly, low free formaldehyde of ester cured phenolic resin was researched. In this part, free formaldehyde emission of the synthesis of products was determined by using acetyl acetone method. According totheoretical analysis, this approach best simulated industrial production of formaldehyde release. In this section, Low-formaldehyde was studied by improving synthetic process and joining two agents reduced formaldehyde. Finally, curing and its performance of ester cured phenolic resin were preliminarily analyzed. Structure of phenolic resin was characterized by infrared spectroscopy. Structure of phenolic resin and its changes before and after curing were gained from the theoretical.