固体核磁共振研究半晶聚-3-羟基丁酸酯和聚羟基丁酸戊酸酯的分子动力学（英文）

Molecular Dynamics of Semi-Crystalline Poly(3-Hydroxybutyrate) and Poly(3-Hydroxybutyrate-Co-3-Hydroxyvalerate) Studies by Solid-State NMR Spectroscopy

本文在150~370 K温度范围内,采用固体核磁共振(NMR)测定了半晶聚-3-羟基丁酸酯(PHB),以及3-羟基戊酸酯单体质量分数分别为5%(PHBV5)和12%(PHBV12)的聚羟基丁酸戊酸酯共聚物在实验室坐标系和旋转坐标系条件下质子的自旋-晶格弛豫时间T1和T1ρ.通过弛豫时间随温度变化的理论拟合,分别获得上述半晶聚合物晶区和结晶区的分子动力学参数(包括Ea和τ0).这些结果从分子水平上阐述了PHB结构修饰和增强的原因.

Molecular dynamics of semi-crystalline poly(3-hydroxybutyrate)(PHB)and copolymers poly(3-hydroxybutyrateco-3-hydroxyvalerate)(PHBV)containing 5 wt.%(PHBV5)and 12 wt.%(PHBV12)3-hydroxyvalerate monomer was studied with solid-state NMR spectroscopy.Proton spin-lattice relaxation times in the laboratory frame(T1)and rotating frame(T1ρ)were measured over the temperature range of 150~370 K.Kubo-Tomita expression fitting to the changes of relaxation times with temperature was used to obtain the molecular dynamics parameters(i.e.,Ea and τ0)in the crystalline and amorphous regions of PHB,PHBV5 and PHBV12.These results yielded molecular-level insights into the structural modification and enhancement of the PHB.