高密度增强硬质聚氨酯泡沫塑料的复合泡体结构

Composite Bubble Structure of High-Density Reinforced Rigid Polyurethane Foam

通过对高密度玻璃纤维增强硬质聚氨酯泡沫塑料 (RRPUF)的断裂面形态观察 ,发现RRPUF含有多种形状的泡孔 ,是一种泡孔之间相互连结、贯穿的复合泡体结构。研究结果发现 ,密度分别为 0 .11、0 .3 1及 0 .5 1g/cm3 的RRPUF的泡体结构大致相同 ,都是复合泡体结构 ,但随密度增大 ,泡孔形状更趋于球体 ,泡孔尺寸分布范围变窄 ,平均尺寸减小。还计算了RRPUF的气体体积含量与密度及纤维之间的关系 ,发现其主要与泡体密度有关。此外 ,还初步探讨了复合泡体结构的形成机理 ,指出发泡剂和热分布不均是产生复合泡体结构的主要因素。

The composite bubble structure was observed in high-density reinforced rigid polyurethane foam (RRPUF) with glass fibre through scanning electron microscope, where the bubbles with various shapes contact and overlap. Results showed that for RRPUFs with density of 0.11,0.13 and 0.51 g/cm 3, the structures are almost similar composite bubble structures. However with increasing of the density, the shape is close to the spherical bubble, the distribution range gets narrow, and the average size decreases. Through calculating mathematic correlation among volume concentration of the gas phase in RPUF and the density and glass fibre concentration, it was indicated that the volume concentration of gas phase was mainly related to the density of RRPUF. In addition, mechanism of the formation of the composite bubble structure was explored and it was thought that the main cause was unequal distribution of blowing agent and heat produced during crosslinked reaction.