tailieunhanh - Rubber Compounding - Chemistry and Applications Part 3

Tham khảo tài liệu 'rubber compounding - chemistry and applications part 3', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 2 General-Purpose Elastomers Howard Colvin Riba-Fairfield Decatur Illinois . I. INTRODUCTION General-purpose elastomers played a critical role in the history of the last half of the 20th century. In 1942 the Rubber Reserve program developed both the basic technology and manufacturing capability to make emulsion styrene butadiene rubber SBR just a few years after World War II had interrupted natural rubber supplies. Historians have noted that the scientific contribution to that effort is comparable to the nuclear research program at Los Alamos that occurred at the same time 1 . After the petroleum shortages of the 1970s fuel economy became a primary driving force in the automotive industry and the tire industry was challenged to develop new products that would improve gas mileage. New elastomers based on solution SBR technology proved to be part of the answer. Today the tire industry is challenged to meet new environmental standards while maintaining or improving the vehicle handling ride and durability that has already been achieved. To meet this challenge the rubber technologist must have a thorough understanding of how general-purpose elastomers . polybutadiene styrene butadiene and styrene butadiene isoprene affect compound processability tire rolling resistance tire traction tire treadwear and overall cost of tire components. Use of these elastomers outside of the tire industry requires the same type of understanding of fundamental polymer characteristics and how they affect the final application. This review will describe the basic structure-property relationships between general-purpose elastomers and end-use properties with a focus on Copyright 2004 by Taylor Francis the tire industry. The processes used to make the general-purpose elastomers will be described with an emphasis on how the polymerization variables mechanism catalyst process affect the macrostructure and microstructure of the polymer. It is polymer microstructure and macrostructure that