Polymorphism of a polymer pre-cursor: metastable glycolide polymorph recovered via large scale high-pressure experiments

A novel polymorph of glycolide, the precursor to polyglycolic acid, has been observed at 0.6 GPa. Large scale high-pressure production has been performed and the seeds successfully used to aid crystallisation of the polymorph at ambient pressure. PIXEL calculations confirm the metastable nature of the polymorph. Subsequent experiments show that, whilst initially stable for 12 days, this may be a case of disappearing polymorphism.