The biodegradable co-polymer PBAT (polybutylene adipate terephthalate) is widely used in the production of compostable bioplastic film. According to Wikipedia it is a co-polyester of adipic acid, 1,4-butanediol and terephthalic acid (from dimethyl terephthalate). PBAT is typically blended with thermoplastic starch to make compostable carrier bags and food waste caddy liners.
I believe (rightly or wrongly) that PBAT is partially bio-based and partially petroleum-based? I work with compostable packaging products but I do not have a science background, so I was hoping that someone here might be able to tell me what percentage of PBAT, if any, is oil based?