Miscibility, crystallization kinetics, and mechanical properties of poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate)(PHBV)/poly(3‐hydroxybutyrate‐co‐4‐hydroxybutyrate)(P3/4HB) blends

Abstract

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate)(PHBV)/poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P3/4HB) blend films were prepared by solvent-cast method. The nonisothermal crystallization results showed that PHBV and P3/4HB are miscible due to a single glass transition temperature (T g ), which is dependent on blend composition. The isothermal crystallization results demonstrate that the crystallization rate of PHBV becomes slower after adding amorphous P3/4HB with 19.2 mol% 4HB, which could be proved through depression of equilibrium melt point (T C and 84 C, respectively. FTIR analysis showed that PHBV/P3/4HB blend films would maintain the helical structure, similar to pure PHBV. Meanwhile, with increasing P3/4HB content, the inter-and intrainteractions of PHBV and P3/4HB decrease gradually. Besides, a lower elastic modulus and a higher elongation at break were obtained, which show that the addition of P3/ 4HB would make the brittle PHBV to ductile materials.

Mechanical and thermal properties of poly(butylene succinate)/poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) biodegradable blends

“…Next, a second heating scan was performed from −70 to 200°C. The degree of crystallinity of the PBS (χ c ,1 ) and the degree of crystallinity of the PHBV (χ c ,2 ) phases were estimated with the following equation: where χ c is the degree of crystallinity, Δ H m is the melting enthalpy of the sample, is the melting enthalpy of the 100% crystalline PBS (110.3 J/g) or PHBV (146.6 J/g), and w is the weight fraction of the PBS or PHBV in the blends.…”

Impact of fermentation residues on the thermal, structural, and rheological properties of polyhydroxy(butyrate‐co‐valerate) produced from cheese whey and olive oil mill wastewater

“…The WAXD patterns were deconvoluted and fitted with Lorentzian lines to determine the peaks positions (2θ) and the full width at half‐maximum values of the peaks. The full width at half‐maximum of the peak located at 16.5° and assigned to the (110) reflection of the hydroxybutyrate (HB) crystals was used to compute the crystallite size ( L ). χ c was computed for each sample from the ratio of the summed area of all of the deconvoluted peaks over the area of the whole spectrum.…”

“…The brittleness virtually casts away PHA and PHBV from film packaging applications. Therefore, research efforts to improve PHBV transformation into packages has recently focused on alternative processing routes to limit or eliminate thermal degradation, new formulations with natural fibers and other biodegradable plastics to improve the melt processability, and fermentation of new PHBV containing larger amounts of hydroxyvalerate (HV) …”

Effect of different plasticisers on the mechanical and barrier properties of extruded cast PHBV films

“…By copolymerising hydroxybutyrate with b-hydroxyvalerate to the copolymer PHBV the melting and glass transition point can be decreased and the processing window can be increased http://dx.doi.org/10.1016/j.eurpolymj.2015.04.012 0014-3057/Ó 2015 Elsevier Ltd. All rights reserved. [10,11]. As an effect of increasing the 3-hydroxyvalerate (HV) content, the brittleness of processed PHBV films can be reduced [12].…”