基于聚己内酯多元醇的浇注型聚氨酯弹性体结构与性能的研究(英文)

STRUCTURE AND PROPERTIES OF POLY(ε-CAPROLACTONE)-BASED CASTABLE POLYURETHANE ELASTOMERS

通过配方设计并采用不同相对分子质量的聚己内酯软段多元醇合成了一系列具有不同硬段含量的浇注型聚氨酯弹性体,分别采用动态力学分析、热失重分析、场发射扫描电子显微镜、傅立叶变换红外光谱、差示扫描量热法等表征方式系统研究了弹性体材料的静态/动态性能、热稳定性及微相结构.研究表明:配方的改变对弹性体材料的力学性能、动态性能以及材料的内生热产生很大的影响;提高硬段含量明显能够改进材料的力学性能和热稳定性,但会导致材料更高的内生热;高相对分子质量的软段多元醇赋予材料更好的弹性,但高相对分子质量聚己内酯多元醇的结晶使得分子链段运动能力下降从而导致弹性体的内生热变大.相关的实验及其结果能够加深影响聚氨酯弹性体性能的分子机理的理解,为各种特殊性能的弹性体材料的分子设计提供科学依据.

Thermostability and static/dynamic properties were studied in a series of castable polyurethane elastomers （CPUEs） as a function of selected compositional variables such as hard segment （HS） content and soft segment （SS） molecular weight. Key methods of characterization are dynamic mechanical analysis （DMA）, thermogravimetric analysis （TGA）, field emission scanning electron microscopy （FE-SEM）, fourier transform infrared （FTIR） and differential scanning calorimetry （DSC）. The selected variables affect mechanical properties and dynamic properties as well as heat build-up. The mechanical properties and thermostability are improved with increasing HS content, while the heat build-up becomes bigger. More elasticity are endowed by high molecular weight of SS, but crystallization of the SS with high molecular weight leads to the decrease of the segmental mobility, then the heat generation occurring in the elastomer becomes bigger. These and related experiments have led us to a better understanding of the molecular mechanisms underlying the properties of elastomers. A scientific basis can be obtained for the design of CPUE with a specified set of properties.