Improvement of the thermal properties of poly(3‐hydroxybutyrate) (PHB) by low molecular weight polypropylene glycol (LMWPPG) addition

Abstract

In this work, blends of poly(3-hydroxybutyrate) (PHB) with 5, 10, 15, and 20 wt % low molecular weight poly(propylene glycol) (LMWPPG) have been prepared and characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) with attenuated total reflectance (ATR) accessory and simultaneous thermal analysis (TG/DTA). FTIR and thermal analyses suggested that the presence of LMWPPG led to a maximum crystallinity for the blend PHB/PPG (90/10) blend. The presence of LMWPPG also caused a significant increase of the PHB processability window, i.e., the difference of the melting and degradation temperature, of PHB from 105 to 134 C, which is extremely important for the industrial uses of PHB. This PHB stabilization effect is discussed in terms of an intermolecular interaction of the PHB carbonyl with LMWPPG methyl groups which probably hinders the classical radon b-scission PHB intramolecular decomposition mechanism.

Tributyl citrate as an effective plasticizer for biodegradable polymers: effect of plasticizer on free volume and transport and mechanical properties

“…It is worth noting that the crystallinity of PHB is very high, 64%, and it increases with plasticizer content. Therefore, the addition of the plasticizer facilitates the segmental mobility of the chains promoting further the crystallization of PHB …”

Desenvolvimento e caracterização de filmes à base de Poli(3-hidroxibutirato) aditivado com ZnOnano

“…As bandas vibracionais mais importantes estão apresentadas na Tabela 2 e os resultados obtidos são coerentes com os encontrados na literatura (ROA et al, 2013).…”

On the use of ball milling to develop PHBV–graphene nanocomposites (I)—Morphology, thermal properties, and thermal stability

“…Moreover, another drawback of this polymer is its low thermal stability, making it unstable during melt processing and also limiting its applicability . Several strategies have been developed to overcome these drawbacks, including blending with other polymers, such as poly (vinyl alcohol) (PVA), polypropylene glycol (PPG), and poly‐ε‐caprolactone (PCL) or modification of the homopolymer by incorporation of different monomer types during the fermentation process. Copolymerization with hydroxyvalerate (HV) results in poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV) which has improved mechanical and thermal properties, since incorporation of HV reduces the crystallinity, thus decreasing stiffness and brittleness, and also reducing the melting point without decreasing the thermal stability of the material, although greater improvements in this parameter are still needed .…”