This change makes the processing difficult . it is found that phbv ( poly ( hydroxybutyrate - co - valerate ) will still thermal degrade at the temperature much more lower than the acute thermal degradation temperature 通过研究发现, phbv (聚羟基丁酸-羟基戊酸酯)在其发生剧烈快速热降解的温度以下仍然有热降解行为的发生。