Preparation of High-Performance Biobased Itaconate Elastomer Nanocomposites by Constructing Dual-Cross-Linked Networks

As a high biobased synthetic rubber, an itaconate elastomer is critical for advancing sustainable tire manufacturing, thereby offering a viable solution to mitigate reliance on petrochemical feedstocks and curtail carbon emissions within the rubber industry. In this study, performance comparisons between two industrially available biobased itaconate elastomers (BIE) and commercial solution-polymerized styrene-butadiene rubber (SSBR) indicated that BIE/silica exhibited higher dry sliding/rolling friction coefficients. It is attributed to the superior frictional damping efficiency of side ester groups in BIE compared to styrene and vinyl moieties in SSBR. In addition, to address the inherent challenges of low cross-linking efficiency and network density caused by the molecular structure of BIE, an innovative dual cross-linking system was developed by combining amino-functionalized polysulfide (PDAS) with sulfur. This system simultaneously activated cross-linking reactions at both double bonds and diester groups, enabling efficient vulcanization of the elastomer. Systematic investigations were conducted to characterize the effects of the PDAS dosage on cross-linking density, filler dispersion, and dynamic/static mechanical properties. Validated with a high-performance tire formulation, BIE/silica with the dual-cross-linked system had reached the same level as SSBR/silica in terms of cross-linking density, mechanical properties (tensile strength: 17.4 MPa, elongation at break: 422%), and Akron abrasion resistance. It also showed balanced dynamic mechanical properties (tan δ = 0.744 at 0 °C and tan δ = 0.092 at 60 °C). These results provide data support and a technical path reference for the industrial application of BIE in green tire manufacturing.