The Rubber Division of the American Chemical Society offers courses, some excellent literature, and a librarian to do specific searches on rubber-related topics. Their website is http://rubber.org/
Recommended books are:
Engineering with Rubber, edited by Alan Gent
(hardbound book which is THE reference work for engineers needing to learn about rubber as an engineering material)
Introduction to Rubber Technology
(very easy to read paperback booklet even suitable for nontechnical people)
Fundamentals of Rubber Technology
(more detailed baseline book on materials, processes, some applications, etc.)
Numerous other books are listed as well, which progress further into the field and may not be as useful or easy to read for engineers rather than chemists. The library search service is reasonably priced, and the librarian is really expert in finding what people need.