Polyhydroxybutyrate (PHB) is known to exhibit limitations in terms of thermal stability. Its susceptibility to thermal degradation, particularly when exposed to high temperatures, can hinder its performance in various applications. This study addresses the thermal stability limitations of Polyhydroxybutyrate (PHB) by exploring strategies to enhance its performance through blending with biodegradable polymers. Focusing on the PHB-pectin blend, computational simulations unveil a remarkable 346.92 K increase in the glass transition temperature (Tg), surpassing pure PHB. This elevation indicates strong intermolecular interactions, potentially involving hydrogen bonding, leading to a more rigid and thermally stable polymer system. The heightened Tg has practical implications for critical applications, such as automotive components and electronic devices, where resistance to elevated temperatures is essential. Emphasizing environmental benefits, the study highlights the use of biodegradable and bio-based polymers as eco-friendly alternatives to traditional plastics, contributing to reduced plastic waste. Overall, this research underscores the potential of thermally stable polymers to both enhance material performance and address environmental concerns across diverse industries.