摘要： 为了研究生物基聚酯树脂的合成工艺，并探讨其与环氧体系的低温固化性，采用对苯二甲酸（ TPA）、新戊二醇（ NPG）、生物基单体和偏苯三酸酐（ TMA）为主体，控制酯化反应醇酸比和温度，筛选和调控生物基单体（多元醇、多元酸）的种类和含量，最终合成低温固化粉末涂料用生物基聚酯树脂。采用差示扫描量热仪（DSC）测试其玻璃化转变温度（T_g），凝胶渗透色谱仪（ GPC）测试其相对分子质量，核磁共振波谱仪（¹H NMR）表征其结构；并将合成的聚酯树脂制备成环氧树脂固化粉末涂料，采用 DSC确定涂层固化度，扫描电子显微镜（ SEM）观察其微观结构。结果表明：当酯化温度为 225 ℃，醇酸比为 1. 15，生物基异山梨醇（ BIS）用量为 7%，生物基丙二醇（ BPG）用量为 14%，三羟甲基丙烷（ TMP）用量为 0. 4%，搭配其他单体和助剂，得到的生物基树脂具有较低的黏度、较好贮存稳定性和低色度，且生物基单体占比达到 30%；制备的粉末涂料经过 160 ℃/15 min烘烤固化后，具有优异的流平性、机械性和耐盐雾性；经过 DSC和 SEM分析，所得涂层固化完全且结构致密，附着力良好。

关键词: 生物基聚酯树脂, 低温固化, 环氧树脂, 粉末涂料

Abstract: This article mainly studied the synthesis and process of bio-based polyester resin，and explored its low-temperature curing performance in epoxy systems. A monomersystem comprising terephthalic acid（TPA）， neopentyl glycol（NPG）， selected bio-based monomers，and trimellitic anhydride（TMA）was designed，the molar ratio of alcohol to acid and temperature of esterification reaction were controlled，and the types and contents of bio-based monomers（polyols，polyacids）are screened and regulated. Finally，bio-based polyester resin for low-temperature curing powder coatings was synthesized. The glass transition temperature（T_g）was measured by differential scanning calorimetry（DSC）the average relative molecular weight was measured by gel permeation chromatography（GPC），a，nd the molecular structure was characterized by nuclear magnetic resonance spectrometer（¹H NMR）； and the synthesized polyester resin was prepared into powder coatings cured with epoxy resin. The curing degree of the coating was determined by DSC，and its microstructure was observed by scanning electron microscopy（SEM）. The research results showed that when the esterification temperature was 225 ℃，the molar ratio of alcohol to acid was 1. 15，the contents of bio-based isosorbide（BIS），bio-based propylene glycol（BPG）and trimethylolpropane（TMP）were 7%，14% and 0. 4% respectively，the bio-based resin exhibited low viscosity，good storage stability and low chromaticity，with the proportion of bio-based monomers reaching 30%；after being cured at 160 ℃ for 15 minutes，the prepared powder coating exhibited excellent leveling performance，mechanical properties，and salt spray resistance；confirmed by DSC and SEM analysis，the obtained coatings was completely cured and had a dense structure with good adhesion.

Key words: bio-based polyester resin, low temperature curing, epoxy resin, powder coatings

中图分类号: 

• TQ630. 4