PHA is the generic name for a biopolyester family, consisting of the following polymers, poly(3-hydroxybutylate) (PHB) and poly(3-hydroxyvalerate) (PHV), including their isomeric polymers and co-polymers the characteristic properties of PHA resulting from the chain length and composition could be tuned to various industrial applications. As one solution to this problem, polyhydroxyalkanoates (PHA) have attracted attention as a biomass-based polymer made from non-edible materials. Poly(lactic acid) (PLA) is the most popular biomass-based polymer and is used for daily necessities however, there is a problem of food security because of the use of edible starch as a main raw material. Several NMR parameters were beneficial for analyzing the manufacturing process as the indexes of polymer compatibility and molecular motions.ДЇor the development of a post-petroleum society, recycling resources from biomass is a high priority. Slow molecular motions (kHz order) were enhanced more by the addition of PBS than PLA, although rapid molecular motions (MHz order) were enhanced by either polyester. Meanwhile, the decrease of T 1C values was dominated by increasingly rapid molecular motions of PHB because of the lowered crystallinity due to the plasticization. A variable temperature relaxation time analysis showed that the decrease of T 1H values was dominated by the 1H spin diffusion via the interface between PHB and the added polyester because of the good compatibility.

Both the signals of 1H MAS (magic-angle spinning) and 13C PST (pulse saturation transfer) MAS nuclear magnetic resonance (NMR) spectra were sharpened and increased by copolymerization with PBS. For the case of a poly(3-hydroxybutyrate) (PHB) unit in plasticized PHA, copolymerization of either PBS or PLA decreased 1H and 13C spin-lattice relaxation times in the laboratory frame ( T 1H and T 1C) in the same manner, while PBS produced a lower 1H spin-lattice relaxation time in the rotating frame ( T 1 ПЃH) than PLA. The molecular mobility and compatibility of plasticized polyhydroxyalkanoates (PHA) were investigated, focusing on changes due to copolymerization using either flexible poly (butylene succinate) (PBS) or rigid poly(lactic acid) (PLA) units.

Nuclear time pst