1. Novel polybutadiene rubber with long cis-1,4 and syndiotactic vinyl segments (CVBR) for high performance sidewall of all-steel giant off-the-road tire.
- Author
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Zhu, Han, Tang, Ming, Hao, Yan-qin, Zhou, Zhi-feng, Sun, Du, Yu, Pei-fu, and Wu, Yi-xian
- Subjects
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POLYBUTADIENE , *FATIGUE limit , *ELASTIC modulus , *FATIGUE cracks , *FRACTURE mechanics , *RUBBER - Abstract
The novel polybutadiene rubbers (CVBR) carrying 88–97% of long cis -1,4 polybutadiene segments (cis -PB, cis -1,4 content >98.3%) and 3–12% of long syndiotactic1,2-polybutadiene segments (s PB, 1,2 content >87.0%) could be successfully synthesized via in-situ coordination polymerizations of butadiene in hexanes in our lab and also be scaled up via continuous polymerization process in pilot (scale: 200 t/a). The natural rubber (NR)-based compound formulations containing different contents of CVBR, and carbon black (CB) fillers were developed and the optimized NR/CVBR/CB vulcanizates with 40% of CVBR were manufactured for the sidewall of all-steel giant off-the-road tire. The storage modulus of NR/CVBR/CB compounds and the elastic modulus, tensile strength and tear strength of NR/CVBR/CB vulcanizates could be remarkably increased by increasing CVBR content. The crack generation and growth could be effectively restricted due to both the fast relaxation, the rigid polymer-filler interface and synergistic effect of high cis -polybutadiene and crystalline 1,2-polybutadiene particles on the strain-induced crystallization behaviors of rubber matrix. The heat build-up of NR/CVBR/CB vulcanizates could be greatly reduced by introduction of cis -PB segments in CVBR for the easy mobility and low hysteresis of macromolecular chains. The NR/CVBR/CB vulcanizates with high strength and elastic modulus, good flex fatigue crack resistance and low heat build-up would meet the requirement for high performance sidewall in manufacturing giant all-steel off-the-road tires. The tensile strength and tear strength of NR/CVBR/CB vulcanizates could be remarkably increased by increasing CVBR content. The crack generation and growth could be effectively restricted due to both the fast relaxation, rigid polymer-filler interface and synergistic effect of high cis -polybutadiene and crystalline 1,2-polybutadiene particles on the strain-induced crystallization behaviors of rubber matrix. The heat build-up of NR/CVBR/CB vulcanizates could be greatly reduced by introduction of cis -PB segments in CVBR for the easy mobility and low hysteresis ofmacromolecular chains. The NR/CVBR/CB vulcanizates with high strength and elastic modulus, good flex fatigue crack resistance and low heat build-up would meet the requirement for high performance sidewall in manufacturing giant all-steel off-the-road tires. [Display omitted] [ABSTRACT FROM AUTHOR]
- Published
- 2024
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