铸造用自硬呋喃树脂固化剂的合成工艺研究.pdf

华中科技大学硕士学位论文
国内同类固化剂产品。
(6)对自使呋喃树脂砂的硬化特性K值的分析表明,其值随固化剂总酸度的增
大而下降趋势:在本研究条件下,气温因素大于环境湿度因素,在选用固化剂时,
应首先根据气温确定合适型号的固化剂,再根据环境湿度情况调檠化剂加入量
最后对本研究开发的系列固化剂分别适用的温度湿度范围,以及综合使用的工艺方
法做了总结和归纳
关键词:自硬呋喃树脂固化剂二苯磺酸硫酸氢屮酯磺化酯化红外光
谱分桫
华中科技大学硕士学位论文
Abstract
Due to the advantages of high sand mold strength, great dimensional accuracy, fast
curing rate, high efficiency, low production costs, low labor intensity, perfectly conforms
to the requirements of modern casting technology, no-bake furan resin sand molding
process has been widely used in production, and considered to be the main process of
foundry industry In the future. At the same time, curing agent for no-bake furan resin, the
quality of which is an important guarantee for the development of no-bake furan resin
sand molding, Is a decisive factor to the performance of furan resin sand
In this investigation, a series of casting furan resin curing agents, xylene sulfonic acid
and methyl hydrogen sulfate as the main active ingredient, were synthesized via
concentrated sulfuric acid liquid phase sulfonating method. Besides, lots of researches on
curing mechanism of no-bake furan resin, characteristics and using technology of curing
Gents have been done. The conclusions are as following
(1) Compared with the synthesis of similar products in the market, this series of
curing agents get advantages of low synthesis temperature(the sulphonation temperature
was dropped from about 120 C to 80 C), short reaction time(the sulphonation time was
cutted from 8h to 4h)
(2)Combination of sulfonation and esterification was achieved in this synthesis. So,
there are both xylene sulfonate and dimethyl sulfate In these curing agents. It turned out
that sand molds hardened by this series of products got higher initial strength and final
strength. Besides, this series of curing agents illustrated better moisture resistance, and
met producing demands with less dosage under varieties of environmental conditions
3 )The active ingredients in this series of products are confirmed as aryl sulfonic
acid, sulfonate and dimethyl sulfate by infrared spectroscopy, which means that reactions
during the synthesis process occurred in the manner envisaged. The synthesis process was
divided into two parts, sulfonation and esterification. How synthesis factors affected the
reaction was figured out by analyzing the infrared spectra
4 )In reference to related literatures, based on the results of experiments and SEM
images, the curing mechanism of no-baking furan resin was discussed, including the role
curing agents played in the curing process and how to measure the properties of curing
agents
5)To compare with the synthesis of similar products in the market, experiments on
using life time and curing rate of molding sand mixed with different curing agents were
done. Hardening coefficient K was introduced into this thesis to investigate the hardening