Synthesis of double-ended hydroxyl-terminated poly(cyclohexyl ethylene) via catalytic hydrogenation of double-ended hydroxyl terminated polystyrene

This study synthesized a novel double-ended hydroxyl-terminated poly(cyclohexyl ethylene) (HO-PCHE-OH), and investigated the individual and interactive effects of reaction temperature, time, and stirring speed on the synthesis of double-ended hydroxyl terminated polystyrene (HO-PS-OH) via the anionic polymerization of styrene, employing sodium-naphthalene as the initiator. A central composite design (CCD) combined with response surface methodology (RSM) was utilized for experimental design, process modelling, and optimization. The optimal reaction conditions were determined to be a temperature of 17.9 °C, a reaction time of 46.7 min, and a stirring speed of 189.1 rpm, yielding a styrene conversion of 91.1 %. The synthesized HO-PS-OH was subsequently subjected to catalytic hydrogenation to enhance its properties, achieving complete hydrogenation within 4 h at 170 °C. The successful transformation of HO-PS-OH into double-ended hydroxyl-terminated poly(cyclohexyl ethylene) (HO-PCHE-OH) was confirmed through nuclear magnetic resonance ( 1 H NMR and 13 C NMR) spectroscopy and Fourier transform infrared (FTIR) analysis. Therefore, the complete saturation of the 6-member carbon ring in HO-PCHE-OH was chemically and photochemically inert. Furthermore, the thermogravimetric analysis revealed that HO-PS-OH exhibited thermal resistance, with a degradation onset temperature of 420.85 °C, while HO-PCHE-OH demonstrated a higher degradation onset temperature of 431.55 °C.