| A. Y. Coran's Achievements |
| Vulcanization Chemistry. -- Early in his career, Coran initiated a program of research which lead the way to a basic understanding of delayed action accelerated sulfur vulcanization, a process which is essential in the production of tires and other rubber articles. The purpose of the work was to answer many questions and to solve some of the long-standing mysteries associated with the delayed action vulcanization process. The approaches used were imaginative and the results were definitive. The chemistry of delayed action vulcanization was sufficiently defined to give a chemical rationale for delayed-onset crosslinking. Dr. Coran's world-class research in the field of vulcanization chemistry has become classic. Vulcanization Control. -- Dr. Coran's early work on delayed-action vulcanization led to his invention of new classes of vulcanization-controlling agents and to a major product, N-cyclohexylthiophthalimide (Santogard® PVI). This product is now used throughout the world to prevent premature vulcanization. Santogard PVI is recognized as the most significant product innovation for vulcanization control since the introduction of sulfenamide accelerators. The product has won two international awards for industrial excellence. Thermoplastic Elastomers (TPEs). -- Dr. Coran and his group discovered a new route to thermoplastic elastomers based on dynamic vulcanization, the process of vulcanizing an elastomer during its melt-mixing with molten plastic. The resulting compositions comprise completely vulcanized micron-size particles of rubber dispersed in a thermoplastic matrix. The elastomer phase can be quite voluminous; thus, very rubbery products can be produced which can be processed as thermoplastic materials. Commercial products which were the result of this work are Santoprene® and Geolast® thermoplastic elastomers. Such products are called TPVs (for "thermoplastic vulcanizates," a term coined by Dr. Coran). Thermoplastic elastomers are processed into finished parts with far less expense than are conventional, thermoset elastomers. Other Achievements. -- Dr. Coran has contributed to many aspects of science and technology of rubber and plastics; he is an inventor of an accelerator (Vocol) for vulcanizing EPDM rubber and reinforcing systems for rubber, based on specially treated cellulose fiber (Santoweb®). Dr. Coran made a significant contribution to the understanding of thermodynamic interactions between polymers and diluents (solvents and plasticizers). He also made contributions to understanding the dispersion of fillers into rubber. In addition, he has done work concerned with chemistry to compatibilize blends of polymers to enable the production of high-performance materials wherein the effects of thermodynamic incompatibility are minimized. The recycling of used rubber and other polymers to form useful blends has been a goal of some of this work. Other work has been related to the evolution of phase morphology during the mixing of blends. |
| VULCANIZATION CHEMISTRY, THERMOPLASTIC ELASTOMERS TPEs |