Improving the Compatibility of Biodegradable Poly (Lactic Acid) Toughening with Thermoplastic Polyurethane (TPU) and Compatibilized Meltblown Nonwoven

Abstract

Poly (Lactic Acid) (PLA) is a biodegradable polymer which originates from natural resources such as corn and starch, offering excellent strength, biodegradability, nevertheless its inherent brittleness and low impact resistance properties have limited its application. On the other hand, Thermoplastic Polyurethane (TPU) has high toughness, durability and flexibility, which is one of the most potential alternatives for enhancing the flexibility and mechanical strength of Poly (Lactic Acid) (PLA) by blending it with a compatibilizer. With the aim to improve the mechanical and thermal properties of Poly (Lactic Acid) (PLA) meltblown nonwovens, The Thermoplastic Polyurethane (TPU) was melt blended with Poly (Lactic Acid) (PLA) at the different corresponding proportions for toughening the Poly (Lactic Acid) and the corresponding PLA/TPU MBs (meltblown nonwovens) were also manufactured. Joncryl ADR 4400 is mixed into the PLA matrix during processing. It was found that Joncryl had a much higher chain extension that substantially increased the molecular weight of the PLA matrix. SEM study revealed that Joncryl ADR 4400 is a good compatibilizer. Moreover, in this study, the crystallization, thermal and rheological behaviors of the corresponding PLA and TPU blends were also investigated. PLA/TPU MBs were also characterized by morphology and mechanical properties. The rheological property of the PLA/TPU meltblown nonwoven revealed that the viscosity is increasing as the amount of TPU is increasing in the blend, PLA/TPU meltblown nonwovens exhibited excellent mechanical properties; they are soft, elastic, and have certain tensile strength. New materials have potential applications in the medical and agricultural fields. Joncryl ADR 4400 compatibilized blends showed higher strength than simple PLA/TPU blends at the same PLA/TPU ratio.