Highly Efficient Complete Hydrogenation of (Polystyrene- b -Poly(styrene- alt -1,3-pentadiene)- b -Polystyrene) Triblock Copolymer Using a Low-Cost Ni-Based Catalyst

High Resolution Image Download MS PowerPoint Slide The design and control of the chain architecture are crucial for the development of polyolefins with defined properties. Herein, we synthesized a type of symmetrical and well-defined triblock copolymer (poly(styrene)- b -Poly(styrene- alt -1,3-pentadiene)- b -Poly(styrene), (S m - b -(SP) n - b -S m = SSPS)) with gradient compositions F ST and constant molecular weights ( M n(designed) = 100 kDa) as well as narrow molecular weight distributions (1.03 < Đ M s < 1.07) by living sequential anionic copolymerization. Subsequently, the highly efficient complete hydrogenation over the low-cost Ni-based catalyst (including Raney nickel and Ni 0 . 2 @Al 2 O 3 ) was carried out to produce a novel kind of Poly(vinylcyclohexane)- b -Poly(vinylcyclohexane- alt -ethylene/propylene)- b -Poly(vinyl-cyclohexane) (VCH m -(VCH- alt -EP) n -VCH m = fh SSPS) multiblock copolymers containing strictly VCH- alt -EP alternating sequences and with narrow Đ M s and complete degree of hydrogenation (HD). Moreover, the complete hydrogenation kinetics was investigated in detail and the hydrogenation process conditions (including reaction temperature and time, H 2 pressure, polymer concentration, polymer molecular weight, and catalyst dosage) were optimized. In addition, the resulting copolymers before and after complete hydrogenation modification were well characterized by nuclear magnetic resonance (NMR), Fourier-transform infrared (FTIR), differential scanning calorimetry (DSC), and gel permeation chromatography (GPC). Finally, the effect of the block ratio of these triblock copolymers before and after modification on the impact strength, flexural strength, and yield strength of transparent resin was investigated. The impact strength and flexural strength reached a good balance value at F ST = 0.80 for SSPS, while at F ST = 0.76 for fh SSPS.