热塑性聚氨酯/低熔点聚酯共混改性及其薄膜的制备与性能研究

通过熔融共混的方法制备Estane^®热塑性聚氨酯（TPU）和低熔点聚酯的共混物，并吹制成膜。分别对共混体系进行DSC，FTIR，SEM和流变性能以及对薄膜进行剥离强度、透湿量和耐静水压的分析测试。结果表明：TPU与低熔点聚酯具有一定的相容性;TPU中低熔点聚酯质量分数≤30%时，低熔点聚酯能够以细小且规则球形颗粒分布在TPU基体中;低熔点聚酯的加入能够大大提高TPU薄膜的热熔粘合性能，并能显著降低粘合温度，但是会对薄膜的透湿性 和耐水压性产生不利影响。试验表明低熔点聚酯质量分数为20%时的TPU薄膜能够满足使用要求。

Preparation, morphology, rheology and properties of thermoplastic polyurethane/low melt point polyester blends used as moisture vapor permeable films

Blends of Estane^® thermoplastic polyurethane (TPU) and low melt point polyest er were prepared via melt blending and the blend films were prepared via blow mo lding. The morphology, thermal properties and rheology of the blends, and the p roperties as moisture vapor permeable films were studied. Differential scanning calorimetry (DSC) and Fourier transformed infrared (FTIR) investigation indicate d that the hard segments of the TPU was compatible with the low melt point polye ster. Scanning electron microscopy (SEM) micrographs exhibited a particle dispe rsed type of the morphology, in which the low melt point polyester was finely di spersed as regular spherical particles in the TPU matrix when the content of the low melt point polyester was below 30%. Evaluations on the properties of th e blend films demonstrated that the incorporation of the low melt point polyeste r co uld enhance significantly the adhesive strength of the TPU film, but it deterior ated the moisture vapor permeability and the waterproofness. The blend films will still balance the comfort and the laminating processability as long as the con tent of the low melt point polyester is controlled to an appropriate level, i.e. below 20%.