封闭多官能异氰酸酯交联发泡剂的研制及PA6发泡成型初探

Preparation of Blocked Polyfunctional Isocyanate and Its Application Used as Crosslinking and Foaming Agents in PA6 Extrusion Foaming

以甲苯二异氰酸酯(TDI)、六亚甲基二异氰酸酯(HDI)、聚醚多元醇为主要原料合成了多官能异氰酸酯预聚体并用无水甲醇封闭,得到封闭多官能异氰酸酯预聚体(BI),并将其作为交联剂和发泡剂用于聚酰胺6(PA6)的挤出发泡成型,通过傅里叶红外光谱仪、扫描电子显微镜、熔体流动速率仪等分析研究了封闭前后多官能异氰酸酯预聚体的结构变化及不同BI含量对PA6熔体强度和泡孔结构的影响。结果表明,随着BI含量的增大,PA6的熔体强度显著提高,泡孔变得更细密、均匀。

Toluene diisocyanate, hexamethylene diisocyanate, and polyether polyol were used to synthesize polyfunctional isocyanate and it was blocked by methanol. Experimental studies showed that it was suitable to use the blocked isocyanate as crosslinking and foaming agent for PA6 foaming. Effect of the content of blocked isocyanate on the melt strength and cellular morphology were investigated. With increasing proportion of blocked isocyanate, the melt strength of PA6 mixture significantly increased and cellular morphologies of the sample turned better.