Study of the Structuring Process of Butadiene–Styrene Rubber in the Presence of Ethylphenylsilylcarbamide and 2-Amino-4,6-bis(trichloromethylsilyl)triazine

Abstract

The role of a new class of active low‑molecular‑weight compounds, ethylphenylsilylcarbamide and 2‑amino‑4,6‑bis(trichloromethylsilyl)triazine, as accelerators of vulcanization of butadiene–styrene rubber was investigated. In the systems butadiene–styrene rubber + 30% ethylphenylsilylcarbamide + ZnO and butadiene–styrene rubber + 30% 2‑amino‑4,6‑bis(trichloromethylsilyl)triazine + ZnO, it was found that the introduction of ethylphenylsilylcarbamide significantly improves the rheological and structural parameters of these systems. First, ethylphenylsilylcarbamide was synthesized; the yield of the final product was 86%. Crosslinking of the butadiene–styrene rubber was carried out in the presence of ethylphenylsilylcarbamide. To protect the compounds from oxidation and from degradation of the polymer chains during mechanical plasticization, the antioxidant 2‑amino‑4,6‑bis(trichloromethylsilyl)triazine was used, and ZnO was used to accelerate the crosslinking of butadiene–styrene rubber. A polymeric plasticizer (a blend of polyvinyl chloride and mineral oil) was used as the plasticizer. Changes in the molecular structure and the three‑dimensional network of the butadiene–styrene rubber in the presence of ethylphenylsilylcarbamide, 2‑amino‑4,6‑bis(trichloromethylsilyl)triazine and zinc oxide were determined by physicochemical and spectroscopic methods. It was found that the degree of crosslinking and the number of active network chains in the elastomer depend on the vulcanization time for each studied system. IR and EPR spectroscopy identified transformations of the butadiene–styrene rubber and confirmed a radical mechanism for the crosslinking reaction. It was shown that the introduction of low‑molecular additives, such as polymeric plasticizers and carbon black, provides improved physicomechanical properties as well as effective protection of elastomeric materials against thermal aging. It was established that plasticization of the elastomer increases with the rise in the content of polar groups (N, NH, Cl, Si) in its composition.