This work deals with the thermal stability of poly[(R)-3-hydroxybutyrate] (PHB) obtained by different isolation methods. PHB was recovered from bacteria by digestion with three different reagents (acid, base, surfactant) and by chloroform extraction as a reference. Thermal stability of the samples was investigated by differential scanning calorimetry, isothermal degradation with hot press, and gel permeation chromatography and was compared with the stability of commercially available PHB. PHBs recovered by digestion with alkaline reagents were found to be thermally unstable, compared to the extracted polymer and the commercially available one. Two different techniques for stabilization of PHB obtained by digestion methods were tested wash with acid solution or addition of carboxylic acid or anhydride before heating. Both methods proved to significantly increase the thermal stability.

这项工作涉及通过不同分离方法获得的聚 [(R)-3-羟基丁酸酯] (PHB) 的热稳定性。通过用三种不同的试剂（酸、碱、表面活性剂）消化并通过氯仿提取作为参考，从细菌中回收 PHB。通过差示扫描量热法、热压等温降解和凝胶渗透色谱法研究了样品的热稳定性，并与市售 PHB 的稳定性进行了比较。与提取的聚合物和市售的聚合物相比，发现通过碱性试剂消化回收的 PHB 是热不稳定的。对通过消化方法获得的稳定 PHB 的两种不同技术进行了测试，在加热前用酸溶液洗涤或加入羧酸或酸酐。