An investigation of the microbiological deterioration of vulcanized rubber

Abstract

The aim of this investigation was to establish the relative resistance of natural and synthetic rubbers to microbial attack, study the influence of formulation on the rate of deterioration of vulcanized natural rubber, isolate and characterize the rubber-deteriorating micro-organisms and determine the mechanism of rubber degradation.

To achieve these aims it was necessary to make a critical assessment of the scientific literature and develop quantitative methods of measuring the rate of microbiological deterioration of vulcanized rubber. In the belief that a number of approaches to a problem yields a more complete description of a phenomenon, a range of techniques, including enrichment culture, pure culture experiments, Warburg micro-respirometry, the biochemical oxygen demand test, tensile properties measurement and scanning electron microscopy were applied to the problem in this investigation. Emphasis was placed on the interactions of the micro-organisms, vulcanized rubber and environments favouring the microbiological deterioration of the material in an attempt to arrive at a satisfying description of this phenomenon.

The thesis is divided into two parts, the first containing an introduction to the discipline of biodeterioration, background information on rubber technology and the results of a survey on the prevalence of the microbiological deterioration of natural rubber pipe-joint rings in the Christchurch Drainage Board area; and the second part, the description of experimental work undertaken in this investigation. The relevant literature is reviewed at the beginning of each chapter.