Study on the structure and properties of SSBR with large-volume functional groups at the end of chains
β Scribed by Lei Wang; Suhe Zhao; An Li; Xingying Zhang
- Book ID
- 104088236
- Publisher
- Elsevier Science
- Year
- 2010
- Tongue
- English
- Weight
- 993 KB
- Volume
- 51
- Category
- Article
- ISSN
- 0032-3861
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β¦ Synopsis
Solution polymerized styrene-butadiene rubber (SSBR) and SSBR with tert-Butylchlorodiphenylsilane (TBCSi, large-volume functional groups) at the two ends of macromolecular chains (T-SSBR) were prepared by anionic polymerization. The molecular structure parameters of T-SSBR and SSBR were characterized and the ratio of the amount of macromolecular chain ends connected with TBCSi to total macromolecular chain ends (i.e., end-capping efficiency) was calculated. The comprehensive properties of T-SSBR and SSBR composites filled with carbon black (CB) were investigated. The results showed that T-SSBR composites presented lower Payne effect (namely better CB dispersion) than those of SSBR composites, which led to decrease in hardness, internal friction, dynamic compression heat built-up and permanent set of T-SSBR composites, significant increase in tensile strength, elongation at break, tear strength and resilience of T-SSBR composites, and excellent balance between wet-skid resistance and rolling resistance. However, compared with SSBR composites, T-SSBR composites presented longer stress-relaxation time, bigger die-swell and higher apparent viscosity, as well as slightly inferior dynamic-cutting resistance. All the above, owing to the end-capping of TBCSi, which could immobilize the free chain ends of T-SSBR (i.e., to reduce the friction loss of molecular chains and create a greater degree of orientation in the force field), and adsorb CB, the comprehensive performances of T-SSBR were better than those of SSBR and T-SSBR terminated with styrene-TBCSi (T S -SSBR) were far superior to those of T-SSBR terminated with butadiene-TBCSi (T B -SSBR). Accordingly, the former was suitable for the tread of green tires.
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A novel synthetic route to heterobifunctional poly(ethylene glycol) containing both amino and carboxylate terminal groups was established via anionic polymerization of ethylene oxide using (cyanomethyl)potassium as the initiator, followed by the successive conversion of the end-hydroxyl group to a p