Effect of Storage Material and Aging on Quality Parameters of Shellac

Abstract

Study was carried out to assess the changes in quality parameters of shellac stored in different storage materials under ambient environment. The qualitative parameters i.e. flow (fluidity), life (heat polymerization time), impurity, moisture content and acid value of shellac were evaluated initially before storage experiment and continue till 18 month from the date of storage on quarterly basis. Flow was found to decrease rapidly after 6 months of storage period. Life of shellac decreases gradually up to 1 year and then remains stable up to 1½ year of storage. The decreasing trend of life of shellac was similar in all the samples stored in different
storage materials after storage duration. Maximum increase in impurity was noticed in samples stored in poly propylene (PP) and jute bag (JB) and minimum increase was observed in samples stored in the low density poly ethylene (LDPE).
There was no appreciable change in acid value. Study indicated that aging deteriorated quality of shellac during storage. As there was no appreciable effect of different storage materials on quality parameters of shellac on storage, LDPE (50.8 µ) the cheapest storage materials can be used for storage of shellac.