AP-02: Enhancing Mechanical and Thermal Performance of PLA Biopolymer through Innovative PBS Blendin

Abstract

Plastics are ubiquitous in our daily lives, and unfortunately, they have also made their way into our natural environment. Their chemical stability, or lack thereof, is a significant concern. Biodegradable polymers have emerged as a crucial area for material innovation[1]. They are anticipated to play a pivotal role in waste reduction, leading to biopolymers with properties akin to conventional polymer materials. However, the inherent fragility of biopolymers and their susceptibility to uncontrolled degradation, as well as their potential for thermosetting, pose substantial and pivotal challenges. These challenges constitute vital scientific issues that polymer researchers grapple with. In this context, biobased polymers like poly(lactic acid) (PLA) have the potential to offer favorable properties and the ability to biodegrade when dispersed in air, soil, or water[2]. However, they remain brittle (rigid and prone to fracture), susceptible to thermal degradation, and crystallize slowly[3]. To overcome these limitations, the option of blending them with another preferably biodegradable polymer is considered to enhance their properties[4]. In this study, our focus centers on the blending of PLA with poly(butylene succinate) (PBS), achieved through the melt blending method with various compositions. The aim is to select the appropriate composition that exhibits specific improvements. Polybutylene succinate (PBS), a biodegradable aliphatic polyester produced through the polycondensation reaction of 1,4-butanediol with succinic acid[5], is often combined with PLA to address different strength-related shortcomings. It boasts high flexibility, excellent impact resistance, and good thermal and chemical durability[6]. The impact of PBS on PLA's properties has been investigated using Fourier-transform infrared spectroscopy (FTIR), rheology, dynamic mechanical analysis (DMA), and differential scanning calorimetry (DSC). DSC analysis revealed miscibility in the PLA/PBS blend with the addition of 10% weight of PBS, whereas other PBS concentrations induced phase separation in the blends. Rheological results highlighted that the 80/20 blend exhibits the highest thermal stability. Tensile tests also demonstrated that the 80/20 blend had good elongation at the break at 35°C, whereas the 90/10 blend exhibited favorable compatibility compared to other ratios. The compatibility of PLA/PBS blends was confirmed through DSC and DMA by an increase in the glass transition temperature (Tg), potentially enhancing crystallinity speed and thermal resistance of PLA. In conclusion, addressing the challenges of compatibility, miscibility, and temperature effects in the PLA/PBS blend is pivotal for achieving a consistent, high-quality homogeneous mixture. These findings hold the potential to not only advance industrial applications but also enhance the efficiency and effectiveness of processes like blow molding, showcasing the significance of continued research in this field