Lee Schechtman - Preparation and Properties of a Novel Class of Polyhydroxyalkanoate Copolymers

Version 1

      Publication Details (including relevant citation   information):

      Noda, Isao, Green, Phillip R., Satkowski, Michael M., Schechtman,   Lee A. Biomacromolecules 1988  6 (2) 580-586

      Abstract: Polyhydroxyalkanoates (PHAs) are   biodegradable aliphatic polyesters, known to be produced by many   common microorganisms. Nodax is a recently introduced family of   PHA copolymers comprising 3-hydroxybutyrate units and a   relatively small amount of other medium chain length   3-hydroxyalkanoate (mcl-3HA) comonomers with side groups of at   least three carbon units or more. There are several different   grades of copolymers available, depending on the average   molecular weight, average mcl-3HA content within the copolymer,   and side group chain length of the chosen mcl-3HA unit. PHA   copolymers with different mcl-3HA types and contents can be made   either by bacterial fermentation or by chemical synthesis. The   incorporation of mcl-3HA units into PHAs effectively lowers the   crystallinity and Tm in a manner similar to the effect of   α-olefins in linear low-density polyethylene. The Tm can be   lowered well below the thermal decomposition temperature of PHAs   to make this material much easier to process. The reduced   crystallinity provides the ductility and toughness required for   many practical applications. The mcl-3HA content regulates the Tm   and crystallinity of copolymer almost independently of the branch   size, as long as more than three carbons are present in the side   group. On the other hand, the side group chain length of the   mcl-3HA has a profound effect on the flexibility of copolymer.

      Address (URL): http://dx.doi.org/10.1021/bm049472m