What Factors Would Affect the Biodegradability of Natural Rubber Latex Products?

Manufacturer: We are a group of 3 students studying the biodegradability of natural rubber latex dipped products. We would appreciate very much if you could give us some information on the major factors influencing biodegradability of latex products.

John Woon (Senior Latex Consultant): I'm happy to learn of your interest in biodegradability (sometimes referred to as the ability to undergo environmental degradation) of latex products. This study would be important from the point of view of waste disposal. Microbial degradation or disintegration of rubber products are largely affected by the following:

1) Crosslink density - usually measured indirectly via the modulus.
2) Filler loading - Under different conditions, this might increase or reduce the biodegradability.
3) Thickness of products -Thinner products with higher modulus or higher crosslink density could have lower degradation than thicker products with lower crosslink density. It has been reported that natural rubber latex condoms would not degrade as fast as the thicker latex examination gloves due mainly to the higher modulus of the condoms.
4) Ratio of surface area to volume. The higher the ratio, the higher would be the chances of degradation.
5) Generally, the higher modulus version of prevulcanized latex (PV) would degrade at a slower rate compared with the lower modulus version of PV.
6) The presence of polyunsaturation in natural rubber would further enhance the degradation through free radical chain reaction.
7) Microbiological degradation is often favoured by the absence of light, high humidity and adequate minerals.
8) pH - Bacteria function best in pH in the range of 5 to 7.