Supernucleation, crystalline structure and thermal stability of bacterially synthesized poly(3-hydroxybutyrate) polyester tailored by thymine as a biocompatible nucleating agent
writer：Ma Huimin, Wei Ziyu, Zhou Shanshan, Zhu Haibo, Tang Jingjing, Yin Jing, Yue Junjie, Yang Jinjun
keywords：PHB, Supernucleation, Crystalliztion, Aggregated structure
source：期刊
specific source：International Journal of Biological Macromolecules
Issue time：2020年
Naturally occurring thymine (TM) was incorporated into bacterial poly(3-hydroxybutyrate) (PHB) polyester
to fabricate a novel and green biocomposite. Both 0.5% and 1% TMexhibit supernucleation effect on PHB,
and crystallization kinetics suggests TM significantly increased Tc and Xc, and substantially shortened t1/2 of
PHB. Epitaxial nucleation caused by a perfect crystal latticematching between PHB and TM,was proposed to
elucidate nucleation mechanism of PHB. Hydrogen bond interaction exists between C_O, C–O–C groups of
PHB and –CH3 (or –CH)/–NH– group of TM. TM interacted with C_O group of PHB crystalline phase rather
than that of amorphous one. In addition, two new IR crystalline bands assigned to C–O–C group of PHB appeared
in the presence of TM, which arises from shift of two amorphous ones, respectively. TM enhanced
onset thermal degradation temperature of PHB, mainly attributed to increased degree of crystallinity of
PHB and flame retardance effect of TM.