Crystallization, thermal, and compatibility performances of poly (butylene succinate) (PBS)/poly((R)-3-hydroxybutyrate-co-(R) 3-hydroxyhexanoate) (PHBHHx) blends

Biodegradable materials provide protective properties comparable to conventional plastics while diminishing reliance on nonrenewable resources. Environmentally friendly polymer blends were prepared by melting poly(R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate) (PHBHHx) with poly (butylene succinate) (PBS). PBS was synthesized through esterification and polycondensation using 1,4-butanediol and succinic acid, with tetrabutyltitanate as the catalyst. The PHBHHx is supplied by Bulepha®PHA Company of China, model number BP330. The effects of PHBHHx content on thermal behavior, compatibility, and thermal stability of PBS/PHBHHx blends were systematically investigated. Differential scanning calorimetry (DSC) results indicated that the addition of PHBHHx influenced the crystallization behavior, the crystallization temperature ( T c ) of PBS decreased meanwhile, the crystallization half-time of PBS is reduced to 1.5 min compared with neat PBS (5 min) after isothermal is crystallized at 95°C. Polarized Optical Microscopy (POM) images also revealed that crystallization rate accelerated in the blend with increasing PHBHHx content. Rheological and Scanning Electron Microscopy (SEM) analysis demonstrated that incorporating a significant content of PHBHHx reduced compatibility between PBS and PHBHHx. Mechanical property testing indicates that the addition of PHBHHx reduced the toughness of blends. Additionally, the addition of a small amount of PHBHHx imparts a higher crystallinity (56%) and heat resistance of the PBS/PHBHHx blends (78°C) was higher than neat PBS (74°C). Highlights Laboratory synthesis of high molecular weight PBS. Optimal ratios improved crystallinity and thermal stability of blends. A systematic study of the crystallization properties of blends.