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ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Bioproducts Research » Research » Publications at this Location » Publication #419184
Research Project: Bioproducts and Biopolymers from Agricultural Feedstocks

Location: Bioproducts Research

Title: Degradation of poly(3-hydroxybutyrate)by potassium phosphate

Author
item CAL, ANDREW - Olipha Inc
item Kibblewhite, Rena
item Lee, Charles

Submitted to: Polymer Degradation and Stability
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/20/2025
Publication Date: 1/2/2026
Citation: Cal, A.J., Kibblewhite, R.E., Lee, C.C. 2026. Degradation of poly(3-hydroxybutyrate)by potassium phosphate. Polymer Degradation and Stability. Article 8875086. https://doi.org/10.1155/adv/8875086.
DOI: https://doi.org/10.1155/adv/8875086

Interpretive Summary: Poly(3-hydroxybutyrate) (PHB) is a biodegradable polymer that can be used in many applications. The properties, and therefore the uses, of PHB are greatly impacted by the polymer’s molecular weight. Low molecular weight PHB (LMWPHB) can be utilized in many areas, such as the medical field. LMWPHB can also be blended with other biopolymers to enhance the thermal and mechanical properties of the final composites. We have discovered that potassium phosphate, a bulk industrial chemical, can be used at low concentrations to catalyze the rapid degradation of PHB into low molecular weight products. The concentration of the potassium phosphate can be regulated to control the size of the final polymer.

Technical Abstract: Poly(3-hydroxybutyrate) (PHB) is a biodegradable polymer that represents a potential replacement for some traditional plastics. The properties of PHB are impacted by many variables including its molecular weight. There are many applications that can be fulfilled by low molecular weight PHB. We have investigated the use of potassium phosphate as a catalyst for degrading PHB. Potassium phosphate was demonstrated to degrade the polymer in a concentration dependent manner. Low concentrations (0.2%) of potassium phosphate decreased the thermal stability of the polymer and rapidly reduced the molecular weight. Related chemicals (calcium phosphate and potassium sulfate) did not have a significant impact on the thermal stability of PHB.