Aminolysis of Poly-3-Hydroxybutyrate in N,N-Dimethylformamide and 1,4-Dioxane and Formation of Functionalized Oligomers.

The degradation pattern of bacterial poly-3-hydroxybutyrate (PHB) in dimethylformamide (DMF) and dioxane solutions at 100 °C assisted by ethylenediamine, 1,4-diaminobutane and monoaminoethanol was studied. When diamines were introduced into the PHB solution in DMF in the amount of 1 mol of the reagent to 5 or 10 mol of PHB monomers, a rapid decrease in the molecular weight of the polymer was observed. The initial value of the weight average molecular weight (M) 840 kDa had decreased by 20-30 times within the first 10-20 min of the experiment, followed by its gradual decrease to several thousand Da.

Production of Porous Films Based on Biodegradable Polyesters by the Casting Solution Technique Using a Co-Soluble Porogen (Camphor).

Porous films have been prepared from degradable polymers-poly-3-hydroxybutyrate (PHB), poly-ε-caprolactone (PCL) and a blend of these polymers (1:3)-by adding porogen (camphor) to the polymer solution at 10%, 30% or 50% of the total mass of the polymer and porogen, and leaching it out afterwards. After the rinse, camphor content in films decreased to about 0.025%.

Constructing Slow-Release Formulations of Ammonium Nitrate Fertilizer Based on Degradable Poly(3-hydroxybutyrate).

The present study describes construction and investigation of experimental formulations of ammonium nitrate embedded in a matrix of degradable natural polymer poly-3-hydroxybutyrate [P(3HB)] and P(3HB) blended with wood flour shaped as tablets, some of them coated with P(3HB). Kinetics of ammonium release into soil as dependent on the composition of the polymer matrix was investigated in laboratory experiments. The rates of fertilizer release from formulations coated with a biopolymer layer were considerably (two months or longer) slower than the rates of fertilizer release from uncoated formulations, while release from polymer and composite (polymer/wood flour) formulations occurred with comparable rates.

Constructing Slow-Release Formulations of Metribuzin Based on Degradable Poly(3-hydroxybutyrate).

Experimental formulations of herbicide metribuzin embedded in matrices of degradable natural polymer poly(3-hydroxybutyrate) (P3HB) and its composites with poly(ethylene glycol) (PEG), poly-ε-caprolactone (PCL), and wood powder have been prepared in the form of pressed pellets containing 75% polymeric basis (pure P3HB or its composite with a second component at a ratio of 7:3) and 25% metribuzin. Incubation of formulations in soil laboratory systems led to the degradation of the matrix and herbicide release. The most active release of metribuzin (about 60% of the embedded herbicide over 35 days) was detected for the P3HB/PEG carrier compared to the P3HB, P3HB/wood, and P3HB/PCL forms (30-40%).