Crystallization behaviors of poly[(R)-3-hydroxybutyrate-co-4-hydroxybutyrate]/poly(ethylene glycol) graft TEMPO-oxidized cellulose nanofiber blends

To accelerate the crystallization rate of poly[(R)-3-hydroxybutyrate-co-4-hydroxybutyrate] [P(3HB-co-4HB)] that is a microbial and biodegradable polyester, poly(ethylene glycol) graft TEMPO-oxidized cellulose nanofiber (PEG-TOCN) was blended as a nucleating agent. The PEG was only blended and confirmed the effect on the difference between PEG-TOCN and PEG in all samples. The non-isothermal crystallization and isothermal crystallization behaviors of P(3HB-co-4HB) with three kinds of different 4HB contents blended with PEG-TOCN or PEG were investigated by differential scanning calorimeter, wide-angle X-ray diffraction, polarizing microscope and tensile test. The crystallization half time (t1/2) was drastically decreased by blended with PEG-TOCN, indicating that the crystallization rate was accelerated in all cases. The POM images showed that the PEG-TOCN worked effectively to increase both the growth rate and amounts of spherulites of P(3HB-co-4HB). In addition, the crystallinity of PEG-TOCN blending samples was higher than that of non-blended samples in all cases.