生物基可降解水性聚氨酯的制备、表征及性能调控

Preparation, Characterization, and Performance Regulation of Bio-based Degradable Waterborne Polyurethanes

关键词:  聚乳酸  性能可调控  可生物降解  水性聚氨酯

Key Words:PLA  performance adjustable  biodegradable  WPU

摘要:使用内乳化法分别制备聚乳酸基水性聚氨酯（PLA-WPU）与聚己内酯基水性聚氨酯（PCL-WPU），然后将PCL-WPU与PLA-WPU进行物理共混，制备生物基可降解水性聚氨酯（PLA-WPU-PCLX）。结果表明，当PCL-WPU含量30%时，制备的PLA-WPU-PCL30综合性能较好，结晶性能较纯PLA-WPU与PCL-WPU有明显提升，拉伸强度达22.2 MPa，断裂伸长率为540%，初始热分解温度为290.5 ℃，堆肥降解14天后质量损失率为2.4%。对纸张表面进行施胶，施胶后的纸张接触角由99°提升至112°；与淀粉施胶相比，PLA-WPU-PCL30质量分数5%时，纸张施胶度由16 s增加至71 s，Cobb值由68.4 g/m²降低至44.7 g/m²，抗张强度由4.6 kN/m提升至5.4 kN/m，撕裂指数由1.32 mN·m²/g提升至1.42 mN·m²/g，耐破度由235 kPa提升至273 kPa，耐折度由55次提升至146次。

Abstract:Polylactic acid （PLA）-based waterborne polyurethane （PLA-WPU） and polycaprolactone （PCL）-based waterborne polyurethane （PCL-WPU） were first prepared by internal emulsification， respectively， and then the bio-based degradable waterborne polyurethane emulsion （PLA-WPU-PCLX） was prepared by physical blending of PCL-WPU and PLA-WPU. The results showed that when the PCL-WPU content was 30%， the comprehensive performance of the prepared PLA-WPU-PCL30 was better， the crystallization performance was significantly improved compared with pure PLA-WPU and PCL-WPU， the tensile strength reached 22.2 MPa， the elongation at break was 540%， the initial thermal decomposition temperature was 290.5 ℃， and the mass loss rate after 14 days of compost degradation was 2.4%. After surface sizing， the contact angle of the paper increased from 99° to 112°. Compared with starch sizing，when the dosage of PLA-WPU-PCL30 was 5%， the paper sizing degree increased from 16 s to 71 s， the Cobb value decreased from 68.4 g/m² to 44.7 g/m²， the tensile strength increased from 4.6 kN/m to 5.4 kN/m， the tear index increased from 1.32 mN·m²/g to 1.42 mN·m²/g， the bursting strength increased from 235 kPa to 273 kPa， and the folding endurance increased from 55 times to 146 times.