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.
Highlights
SBS copolymers have a wide range of applications as thermoplastic elastomers
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
The hydroxyl reaction sequence, we examined the three forms of the polymer via FT-IR (Figure 3)
Summary
SBS copolymers have a wide range of applications as thermoplastic elastomers. traditional SBS copolymers have no functional groups meaning that they cannot be chemically modified or cross-linked to obtain alternating embedded copolymers. Polybutadiene with low cis-1,4 content (35–40%) is obtained [2], resulting in a high Tg and poor mechanical properties at low temperatures This is mainly due to limited coordination between the alkyl lithium initiator and the olefin monomers. Thereby, this catalyst fits the current needs in that (a) there are protected hydroxyl groups monomers, is the center of the catalyst to ensure the high cis-1,4 content of the polybutadiene sections. 2. Materials and Methods butadiene polymerization without a cocatalyst, and (c) nickel, which exhibits strong coordination to olefin monomers, is the center of the catalyst to ensure the high cis-1,4 content of the polybutadiene. (99%, Aladdin), butadiene (15 wt % in toluene, TCI Chemicals, Shanghai, China), styrene
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
