Vulcanization Vulcanization Vulcanization (British: vulcanisation) is a chemical process used to harden rubber. Vulcanization traditionally referred to the treatment of natural rubber with sulfur and this remains the most common example, however the term has also grown to include the hardening of other (synthetic) rubbers via various means. Examples include silicone rubber via room temperature vulcanizing and chloroprene rubber (neoprene) using metal oxides. Vulcanisation can therefore be defined as the curing of elastomers; with the terms 'vulcanization' and 'curing' sometimes used interchangeably in this context. It works by forming cross-links between sections of polymer chain which results in increased rigidity and
Sulfur–iodine cycle nuclear reactions, or solar heat concentrators. Sulfur–iodine cycle The sulfur–iodine cycle (S–I cycle) is a three-step thermochemical cycle used to produce hydrogen. The S–I cycle consists of three chemical reactions whose net reactant is water and whose net products are hydrogen and oxygen. All other chemicals are recycled. The S–I process requires an efficient source of heat. The three reactions that produce hydrogen are as follows: The sulfur and iodine compounds are recovered and reused, hence the consideration of the process as a cycle. This S–I process is a chemical heat engine. Heat enters the cycle in high-temperature endothermic chemical