Premium
Study on volume ratio and plasticizer screening of free coating membranes composed of ethyl cellulose and chitosan
Author(s) -
He Wen,
Du Yumin,
Fan Lihong
Publication year - 2006
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.22949
Subject(s) - plasticizer , ethyl cellulose , materials science , solvent , chemical engineering , nuclear chemistry , polymer chemistry , glass transition , ultimate tensile strength , composite material , polymer , chemistry , organic chemistry , engineering
The aim of this study was to optimize the formula of free blended coating membrane of ethyl cellulose (EC) and chitosan (CS), including their suitable ratio range and the best plasticizer used. The dry films were produced by a casting/solvent evaporation method, with different volume ratio of EC and CS solution plasticized by various plasticizers, respectively. The wet films were prepared by immersing dry films in pH 6.8 phosphate buffer saline (PBS) for 24 h. The promising ratio range of EC/CS was below 20/5 or 20/6 with various plasticizer, which was determined by comparing the viscosity of the blended solutions and the morphology of the blended films. The efficiency of plasticization was evaluated by measuring glass transition temperature ( T g ). All the testing plasticizers have good compatibility with EC or CS and dibutyl phthalate (DBP) have the strongest efficiency inducing the lowest T g (39.9°C) of the film. Mechanical properties were evaluated by the ratio of tensile strength ( T ) to elastic modulus ( E ). In the wet state, the films with DBP had the highest T/E value (1.2). The results of leaching of plasticizers also verified that DBP was the most stable plasticizer in the films. The release rates of tetramethylpyrazine phosphate (TMPP) through the pellets coated with the blended films of EC/CS (20 : 6 v/v) plasticized by various plasticizers showed that the more water‐soluble the plasticizer was, the more quickly TMPP dissolved from the coated pellets, which further indicated that the water‐insoluble plasticizers (such as DBP) could be more applicable to keep the sustained or controlled release property of the blended films in wet state. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1932–1939, 2006