Specific heats of collagen and leather

Abstract

of thc specific heats of collagen, vegetablc-tanncd lcathcr , chro lll c-retanned leather, chrome leather, and these materials co nta ining varying p crcentages of m oisture were mad e at 25 ° C. The sam e determinations were also made on dry chestnut a nd qucbracho tanning extracts a nd on a stuffing grease a nd an animal oil. The r es ults obtained with the collagen and leather containing various p ercentages of moisture show abru pt breaks in the curves, which indicate phase changes. Th ese changes a rc ex plained on the basis of changes in the vibrational activity of the polar groups in the collagen moleculc. Lubricating materials, added to leather, increasc the sp ec ifi c hcat. This affects the com fort of the lcather advcrsely during cold weathcr.