Morphology and thermal behavior of poly (3-hydroxybutyrate-co-3-hydroxyvalerate)/poly(butylene adipate-co-terephthalate)/clay nanocomposites

Abstract

Biopolymers are gaining increasing interest because of decline of mineral oil reserves, increasing waste problem, and increasing consciousness of society for environmental problems. However, competitiveness of biopolymers compared with conventional plastics is still limited due to partly insufficient properties and high prices. This study investigates the influence of blending of poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) with poly(butylene adipate-co-terephthalate) (PBAT) as well as the influence of addition of functionalized montmorillonite (OMMT) to the blends on morphology and thermal behavior. Dispersion state and morphology of the nanocomposites are studied by X-ray diffraction as well as scanning electron microscopy. Thermal stability is studied by thermogravimetric analysis and crystallization behavior is studied by differential scanning calorimetry and polarized optical microscopy. With respect to the morphology for the blends it can be seen that the immiscible biopolymers PHBV and PBAT are distributed in interlocking zones. There is a good dispersion and homogeneous distribution of OMMT within the biopolymer blends. The addition of 50% or more PBAT to PHBV as well as the insertion of OMMT enhances thermal stability of PHBV. In the blends, the addition of PBAT retards crystallization of PHBV. The OMMT acts as nucleating agent leading in total to more but less perfect crystals in the blends, and the crystallization slows further due to constraint in the movement of polymer chains. These results contribute to the understanding of the structure-properties relationship of bionanocomposite materials for packaging applications. POLYM. COMPOS., 36:2051-2058, 2015

Non-isothermal melt crystallization kinetics of poly(3-hydroxybutyrate), poly(butylene adipate-co-terephthalate) and its mixture

“…A small increase of the melt crystallization temperature may be attributed to the interference of PBAT on PHB crystal growth. Similar results were reported by Bittmann et al [16] and are fully consistent with the detailed results discussed in the present work.…”

Effect of environmental factors on Poly(3‐hydroxybutyrate‐co−3‐hydroxyvalerate)/Poly(butylene adipate‐co‐terephthalate)/montmorillonite nanocomposites with antimicrobial agents

“…and in Table . It can be seen that the addition of PBAT to PHBV enhances the thermal stability of the polyhydroxyalkanoates, which was already reported in a previous article . By contrast, the addition of nanoclay to the binary mixture of PHBV/PBAT does not alter the temperature of 5% weight loss T 5% = 292°C of the PHBV/PBAT blend.…”

“…Poly(butylene adipate ‐co‐ terephthalate) (PBAT) is a petroleum based but biodegradable polymer with high ductility and low stiffness . By blending of PHBV with PBAT mechanical properties as well as the price can be adjusted . A further possibility of adjusting polymer properties is the addition of fillers.…”

Effect of different biopolymers and polymers on the mechanical and permeation properties of extruded PHBV cast films

“…Further increasing the PBAT concentration had less effect on the aforementioned properties, but a significant increase in ɛ was observed. This may be due to an interlocked distribution of PHBV and PBAT with ‘molecular interaction’ [shown for poly(3‐hydroxybutyrate‐ co ‐3‐hydroxyhexanoate (PHBH)]. The PHBV + PBAT blend had the smoothest surface and slightly bigger spherulites than the pure PHBV film because of the retarded crystallization of PHBV by PBAT .…”

“…This may be due to an interlocked distribution of PHBV and PBAT with ‘molecular interaction’ [shown for poly(3‐hydroxybutyrate‐ co ‐3‐hydroxyhexanoate (PHBH)]. The PHBV + PBAT blend had the smoothest surface and slightly bigger spherulites than the pure PHBV film because of the retarded crystallization of PHBV by PBAT . PBAT thus seems to be a promising blend partner for PHBV, although only increases significantly at greater than 50 wt % in the blend.…”