A New Strategy for the Synthesis of Hydroxyl Terminated Polystyrene-b-Polybutadiene-b-Polystyrene Triblock Copolymer with High Cis-1, 4 Content

Abstract

This work reports the preparation of a hydroxyl terminated polystyrene-b-polybutadiene-b-polystyrene triblock copolymer (SBS) with high cis-1, 4 content via a novel nickel catalyst, [η3-Ni(CH2CHCHCH2OOCH3)][BPhF4]. FT-IR, 1H-NMR, and 13C NMR indicated that the polybutadiene segment of the copolymer contains greater than 90% cis-1, 4 structure, indicating achievement of the objective. Toward the functionalization goal, a hydroxyl group was successfully introduced at the end of the triblock copolymer (HO–SBS–OH). The results of gel permeation chromatography (GPC) revealed that the polymer is indeed a triblock copolymer, with no traces of homopolymer. Differential scanning calorimetry (DSC) showed that HO–SBS–OH synthesized using the novel catalyst had a lower glass transition temperature (Tg) than HO–SBS–OH synthesized with an alkyl lithium catalyst. Therefore, the polymer synthesized via the novel catalyst contains high cis-1,4 content and displays excellent low-temperature mechanical properties.

Using Epoxidized Solution Polymerized Styrene-Butadiene Rubbers (ESSBRs) as Coupling Agents to Modify Silica without Volatile Organic Compounds

“…To improve the performance of silica/rubber nanocomposites and lower the VOCs emission, as opposed to modifying the silica surface, the compatibility of silica and rubber can also be improved by the functionalization of the rubber molecular chain, e.g., introducing functional groups like carboxyl groups [ 24 , 25 ], hydroxyl groups [ 26 , 27 , 28 , 29 , 30 ], alkoxysilane groups, and epoxy groups [ 3 , 20 , 28 ] onto rubber chains during post-polymerization process. Additionally, these functional groups, especially alkoxysilane groups [ 31 , 32 , 33 , 34 ], can be introduced to the polymer chain during the polymerization process, copolymerization, or termination.…”

Composition Analysis of Grafted ABS and its Blend Copolymers Using a Combination of 1H NMR Spectroscopy and Nitrogen Element Analysis

“…In the case of BD, the numbers of unsaturated protons are different in the 1,2 and 1,4 forms, and thus, the signals must be separately calculated. The signal corresponding to the two olefinic protons of 1,4‐BD ( cis and trans ) BD appears to be centered at 5.4 ppm, whereas the vinyl CH 2 and CH protons of 1,2‐BD separately appear at 5.0 and 5.6 ppm (partially overlapping with the 1,4‐BD signal), respectively 30‐33 . The weight compositions of the other monomers can be calculated in the same manner. …”

Recent Developments in Synthesis, Properties, Applications and Recycling of Bio-Based Elastomers

“…Polyols from polybutadiene (PB), polybutadiene rubber (BR), or SBS copolymer have been synthesized. BR has repeating butadiene units, which can be trans or cis -1,4-polybutadiene and are modified with another compound or reagent with hydroxyl (-OH)-terminated groups, which are called “hydroxy-terminated polybutadiene” (HTPB), hydroxy telechelic polybutadiene or polyols; these have been obtained by different methods such as oxidation or oxidolysis [ 67 , 68 ], anionic polymerization [ 69 ], via copolymerization [ 70 ], via nickel catalyst [ 71 ], and by olefin metathesis [ 72 , 73 ]. Other polyols have been obtained from natural rubber (NR), NR comes from the rubber tree, or from its synthetic form, polyisoprene rubber (IR), which has repeating isoprene units and can be trans or cis -1,4-polyisoprene [ 18 ].…”