POLYESTERS PRODUCED BY PSEUDOMONAS-OLEOVORANS CONTAINING CYCLOHEXYL GROUPS

Polymers containing cyclohexyl units were isolated when Pseudomonas ol eovorans was grown with 5-cyclohexylvaleric (CHV) or 4-cyclohexylbutyr ic acid(CHB). This was opposed to the case where shorter chain acids w ere used as carbon sources. Growth experiments using homologous cycloa lkylalkanoic acids as carbon sources were carried out with varying rat ios of the acids to nonanoic acid. A concentration of 90% CHV (20 mM t otal concentration) afforded a polymer in which monomeric units contai ning a cyclohexyl ring (up to 24% of units) were identified by NMR and GC-MS. The polymeric material isolated in about 9% of the dry cell we ight was a beige, sticky material similar in texture to poly(3-hydroxy nonanoate). The polymer's intrinsic viscosity was 0.77 dL/g, and its w eight-average molecular weight 52000, as determined by GPC. Thermal an alysis indicated the presence of two T-g values: T-g1 = -16.3 degrees C and T-g2 = -32.6 degrees C, which suggest the presence of two polyme rs, one containing more cyclohexyl rings than the other. This observat ion was sustained by TLC analysis.