Carothers and Flory-Stockmayer Theory as a new perspective on currently ineffective poly(glycerol sebacate) synthesis and crosslinking

Since 2002, intensive research on glycerol polyester has been ongoing. Poly(glycerol sebacate) (PGS) is most often studied because of its high applicable potential in many medical uses. This polyester is commonly synthesised from glycerine and sebacic acid in a molar ratio G/SA = 1:1. Nowadays, synthesis and thermal crosslinking processes are very time-consuming. At least 24 h for each, sometimes even a few days. There is a lack of works comparing these processes with polymerisation theory, such as Carothers Equations or Flory-Stockmayer Theory. In this work, experiments were performed at characteristic points of molar ratio determined from mathematical modelling. Currently published syntheses and crosslinking processes are characterised by long times, probably due to the use of the wrong molar ratio of monomers. The most effective glycerine to sebacic acid ratio is 2:3, according to both theories. This parameter should be considered for further synthesis optimisation and scaling up. This is also important for industrial implementation due to economic and ecological aspects. Moreover, the study of the G/SA ratio outside the range of 0.5–1.0 has no theoretical and experimental justification.