Synergistic enhancement of magic triangle properties of PC tread stocks modified by amine-capped trans-1,4-poly (butadiene-co-isoprene)

Abstract

The development of high-performance “green tires” with synergistically improved “magic triangle” properties like lower rolling resistance, higher wet-skid resistance and higher abrasion resistance has always been a hot issue. In this work, an effective strategy for developing high-performance “green tires” with simultaneously improved “magic triangle” properties of solution-polymerized styrene-butadiene rubber (SSBR)/cis-1,4-polybutadiene rubber (BR) nanocomposites modified by amine-capped trans-1,4-poly(butadiene-co-isoprene) copolymers (F-TBIR) was proposed. A series of F-TBIR with 10–60 mol% amine-capped efficiency (CE) and 30-90 × 10⁴ weight-average molecular weight (M_w) were synthesized by using heterogeneous TiCl₄/MgCl₂–Al(i-Bu)₃ Ziegler-Natta catalyst with dicyclohexylamine (DCHA) as chain transfer agent (CTA). With the increase in CE of F-TBIR, the silica-filled SSBR/BR/F-TBIR compounds exhibited improved green strength, modulus at 100 % elongation and bound rubber, and their vulcanizates showed synergistically improved “magic triangle” properties like obviously reduced rolling resistance and abrasion loss, and increased wet-skid resistance. It was found that the incorporation of 10 phr F-TBIR3 with CE of 60 mol% and M_w of 32 × 10⁴ resulted in highly expected properties of the SSBR/BR/F-TBIR3 nanocomposite. The contribution mechanism of F-TBIR3 was discussed based on the improvements of polymer network structures and filler network structures. This work is expected to provide an effective strategy to construct the desired network structures for high-performance rubber composites.