新型气硬动物胶型芯粘结剂的制备工艺优化

摘要

A new air hardening core sand binder was made from animal bone glue as the main raw material by alkaline hydrolysis and modification.To improve some disadvantages of animal glue such as agglomeration at normal temperature, consumption of energy and low efficiency, an alkaline hydrolysis process was selected and optimized firstly.With the addition of active groups, animal glue was modified by the reaction of grafting copolymerization and esterification.The bond strength of animal glue binder could be further improved.Finally, air hardening mechanism and modification mechanism of the new animal glue binder were theoretically analyzed.The optimal ratio of modifier was as follows, m(glycerm):m(dextrin):m(ethanol):m(animal glue)= 9:10:9:100.The modification temperature was 75 ℃ and the modification time was 90 min.The original strength was above 0.65 MPa and the compression strength of 24 h was 4.2 MPa, which could meet the requirement of rapidly core-making production.%以动物骨胶为主要原料,经过碱解、改性处理后得到了一种新型CO2硬化型芯粘结剂.针对传统动物胶常温凝聚、热硬消耗能源且效率低的不足,首先选择并优化了动物胶碱解工艺,并引入活性基团对动物胶进行接枝共聚以及酯化改性,进一步提高粘结强度.最后对新型动物胶粘结剂的吹气硬化和改性机理进行了理论分析.结果表明:改性动物胶铸造粘结剂最佳配比为m(丙三醇)∶m(糊精)∶m(乙醇)∶m(动物胶)=9∶10∶9∶100,改性温度75℃、改性时间90 min.吹CO2气体硬化的新型改性动物胶粘结剂,初强度大于0.65 MPa、24h抗压强度达到4.2 MPa,能够满足快速制芯生产要求.