HYDROLYSIS EFFECTS ON THE MASS OF A CROSS -LINKED POLYMER

An epoxy resin has been exposed to conditions of high humidity and tem perature for various periods and then dried, Compared to the original value, the weight after drying initially increases with humidity expos ure time and then falls below. A theory is presented which explains th is behaviour by macromolecular chain scission. The initial weight gain is attributed to chemically attached water, whereas the following los s is associated with a phenomenon of leaching of free segments. The mo del explains satisfactorily the experimental results and leads to an e stimation of mean inter-crosslink molecular weight.