Synthesis and photo- and biodegradabilities of poly[(hydroxybutyrate-co-hydroxyvalerate)-g-phenyl vinyl ketone]

The graft copolymer, poly[(hydroxybutyrate-co-hydroxyvalerate) vinyl ketone ] [CP(HBV-g-PVK)], was synthesized by graft polymerization of phenyl vinyl ketone (PVK) onto poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) under nitrogen atmosphere using benzoyl peroxide. The structure of P(HBV-g-PVK) was identified by Fourier transform TR and H-1-NMR spectra. The effects of weight ratio of PVK to PHBV in feed, initiator concentration, reaction time , and reaction temperature on the grafting ratio and grafting efficiency we re investigated. The thermal decomposition temperature of P(HBV-g-PVK) was 272 degrees C. The tensile strengths of P(HBV-g-PVK) after photo- or biodeg radation were significantly decreased due to degradation by UV irradiation or Aspergillus niger. The value of color difference (Delta E) of P(HBV-g-PV K) was greater than that of PHBV. The film surfaces of P(HBV-g-PVK) treated with UV irradiation and Aspergillus niger showed many pits as compared wit h the untreated P(HBV-g-PVK). It has been found that the photo- and biodegr adabilities of P(HBV-g-PVK) was excellent. (C) 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 1439-1439, 1999.