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通过改变预聚合反应条件制备了不同性能的预聚体,考察了反应条件对预聚体黏度和稳定性的影响。实验结果表明,质量浓度对预聚体黏度的影响远远大于反应时间、甲醛与三聚氰胺(F/M)摩尔比和反应pH值等其他因素,预聚体的稳定性随着F/M摩尔比的减小、反应时间的延长以及质量浓度的降低而增强,随着pH值的增加先增强后减弱。通过合理控制反应条件,可以制得低黏度高稳定性的预聚体和在室温下稳定储存的低F/M摩尔比预聚体。
The prepolymer with different properties was prepared by changing the prepolymerization conditions. The effects of reaction conditions on the viscosity and the stability of the prepolymer were investigated. The experimental results show that the influence of mass concentration on the viscosity of the prepolymer is far greater than the reaction time, the molar ratio of formaldehyde to melamine (F / M) and the pH value of the reaction. The stability of the prepolymer with the F / M molar ratio Decrease of reaction time, prolongation of reaction time and decrease of mass concentration, and then increase and then decrease with the increase of pH value. By reasonably controlling the reaction conditions, a prepolymer with low viscosity and high stability and a low F / M molar ratio prepolymer stored stably at room temperature can be prepared.