Composites of poly(lactic acid)/poly(butylene adipate‐co‐terephthalate) blend with wood fiber and wollastonite: Physical properties, morphology, and biodegradability

Abstract

Poly(lactic acid) (PLA) was first melt blended with five weight percentages (10-50 wt %) of poly(butylene adipate-coterephthalate) (PBAT) on a twin-screw extruder and then injection molded. The blend at 30 wt % PBAT exhibited the highest impact strength and elongation-at-break without phase inversion. The 70/30 (w/w) PLA/PBAT blend with high toughness improvement was selected for preparing both single and hybrid composites using an organic filler, wood fiber (WF) and inorganic filler, wollastonite (WT) with a fix total loading at 30 parts per hundred of resin (phr) throughout the experiment. Five WF/WT (phr/phr) ratios for the composites were 30/0, 10/20, 15/15, 20/10, and 0/30. The prepared composites were investigated for the mechanical and thermal properties, melt flow index (MFI), morphology, flammability, water uptake, and biodegradability as a function of composition. All the composites showed a filler-dose-dependent decrease in the impact strength, elongation-at-break, MFI, and thermal stability, but an increase in the tensile and flexural modulus, tensile and flexural strength, antidripping ability, and water uptake compared with the neat blend. The addition of WF and WT was also found to promote the biodegradability of the PLA/PBAT blend.

Effects of thermoplastic poly(ether‐ester) elastomer and bentonite nanoclay on properties of poly(lactic acid)

“…Upon cooling at 2°C/min after thermal conditioning at 200°C for 5 min, the DSC curves showed no T c of the PLA component in the pure PLA, blends and nanocomposites, while the pure TPEE exhibited a T c at 123°C (Figures 6(a) and 7(a)). This was due to the intrinsically slow crystallization rate of PLA 5,8 . Thus, the PLA phase was almost amorphous after being cooled from the melt, especially in an injection molding process 33…”

Mechanical properties of wollastonite reinforced thermoplastic composites: A review

“…PLA/PBAT blend reinforced with wood fiber and wollastonite were produced in the work of Chaiwutthinan et al Since 70/30 (wt/wt) PLA/PBAT blend composition had the highest elongation at break, it is used as the basic matrix for the polymer composites. Both single and hybrid composites had been prepared.…”

“…Commercially available degradable polyesters include poly(butylene adipate‐co‐terephthalate) (PBAT), polylactic acid (PLA) and poly‐2‐hydroxy butyrate (PHB). Wollastonite reinforced biodegradable polyester composites generally improved tensile and flexural properties, but there is some contradict works on the effect of wollastonite on elongation at break …”

“…There are three works revealed that the impact strength decreased with the increasing wollastonite content in the composites . This is due to the stress concentration by wollastonite.…”

Biodegradable Poly(butylene adipate‐co‐terephthalate) composites reinforced with bio‐based nanochitin: Preparation, enhanced mechanical and thermal properties

“…Among the biodegradable polymers developed to date, poly(butylene adipate‐co‐terephthalate) (PBAT) is generally considered the most suitable alternative to low‐density polyethylene, sharing many similar properties including flexibility and resilience . Although first commercialized decades ago, the use of PBAT in packaging and agricultural films remains limited due to the higher production cost and generally inferior physical properties compared with many of the nonbiodegradable petrochemical‐based polymers traditionally used in these applications . Improvements in the physical properties of PBAT composites, together with the increasing social and environmental pressures to switch to biodegradable polymers, should result much wider utilization of PBAT‐based polymers in the near future.…”