Chapter 6: Future Trends in the Use of Rubber with Food
6.1 Increased Use of Thermoplastic Rubbers and High Performance Rubbers
A search of any major abstract database reveals the extent to which new thermoplastic rubbers are entering the food contact market. The attraction of these materials is that they are relatively simple compared to conventional rubbers, which means that they contain less potential migrants overall, and none of those which have received the closest scrutiny in recent years (e.g., nitrosatables and primary aromatic amines). In the main they have entered the market in one of two ways: as replacements for existing rubbers, and as replacements for other food contact materials. There are a number of examples of TPEs replacing vulcanised rubbers in the literature. For example, a co-polyester based TPE with high temperature resistance has been developed to replace rubbers such as silicone (11). A recent development is the manufacture of polyurethane TPE food contact gloves as an alternative to natural rubber or nitrile rubber gloves (62), and there is the continuing utilisation of thermoplastic vulcanisates such as Santoprene as an alternative to conventional vulcanisates (38). For the manufacture of babies teats and dummies, high performance clear TPEs based on styrene-block copolymers are competing with silicone rubber for this application (54).
An example of TPEs replacing other food contact materials is the use of SEBS block copolymers to manufacture synthetic corks for use in wine bottles instead of natural cork (99). This trend has been assisted in recent years with the continued proliferation of thermoplastic vulcanisates (TPVs). These materials...