Biodegradability of gelatin-PF resin blends by soil burial method

Cured gelatin-phenol formaldehyde (PF) resin blends have been tested for their biodegradability under soil burial test conditions. Over a period of two weeks and at an ambient temperature of 27 degrees C, the blends were found to be significantly resistant to biodegradation in the test soil up to a composition of 7:3 gelatin to resin ratio. At higher gelatin contents, the blends suffered extensive degradation. Scanning electron micrographs of the blend films after the tests showed extensive bacterial growth. Inorganic inclusions, presumably calcium salts, that are inherently present in gelatin are believed to support bacterial growth and biodegradation of the blends. (C) 1998 Elsevier Science Limited. All rights reserved.