The combination of a living anionic technology and a unique alternating strategy provided an exciting opportunity to prepare novel and well-defined poly(1,3-pentadiene-co-syrene-co-1,1-diphenylethylene) resins consisting of three alternating sequences of modules (A/B/C zwitterions). “A” being Styrene (St)/1,3-pentadiene (PD), “B” being diphenylethylene (DPE)/PD, “A” being DPE/St, respectively, A wide composition range of new polyolefin resins, i.e., poly (A-co-B), poly (A-co-C), and poly (B-co-C), with controlled molecular weight and very narrow molecular weight and composition distributions have been prepared by a one-pot living characteristic method. In the section of kinetic analysis, the terpolymer yields and kinetic parameters were strongly dependent on the feed/comonomer ratio as well as the content of the alternating structure. The competition copolymerization behaviors of A/B, B/C, and A/C were studied in detail in this work. By contrast, the microstructure and the thermal property of the resulting terpolymer were investigated via Nuclear magnetic resonance (NMR) and Differential scanning calorimetry (DSC) analysis. The results of 1H NMR tracking the change of [Aromatic ring]/[C=C] value indicated the distinctive copolymer-ization behavior of the selective “alternating-modules”. The glass transition temperature (T_g) was very sensitive to the terpolymer composition. By contrast to poly(A-ran-B) with only one obvious T_g, there were two T_gs in the A/C and B/C copolymerization cases. Moreover, the desirable high T_g ~ 140 °C resin was limited to the terpolymers with up to 50 mol % DPE. Finally, the “ABC-X” mechanism was proposed to interpret the unique terpolymerization behavior, which belongs to the classical “bond-forming initiation” theory.

One of the most effective strategies for modifying the surface properties of nano-fillers and enhancing their composite characteristics is through polymer grafting. In this study, a coprecipitation method was employed to modify hydroxyapatite (HAP) with epoxidized soybean oleic acid (ESOA), resulting in ESOA-HAP. Subsequently, oligomeric poly(lactic acid) (OPLA) was grafted onto the surface of ESOA-HAP, yielding OPLA-ESOA-HAP. HAP, ESOA-HAP, and OPLA-ESOA-HAP were comprehensively characterized. The results demonstrate the progressive grafting of ESOA and OPLA onto the surface of HAP, resulting in enhanced hydrophobicity and improved dispersity in organic solvent for OPLA-ESOA-HAP compared to HAP. The vitality and adhesion of Wistar rat mesenchymal stem cells (MSCs) were assessed using HAP and modified HAP materials. Following culture with MSCs for 72 h, the OPLA-ESOA-HAP showed an inhibition rate lower than 23.0% at a relatively high concentration (1.0 mg/mL), which is three times lower compared to HAP under similar condition. The cell number for OPLA-ESOA-HAP was 4.5 times higher compared to HAP, indicating its superior biocompatibility. Furthermore, the mechanical properties of the OPLA-ESOA-HAP/PLLA composite almost remained unaltered ever after undergoing two stages of thermal processing involving melt extrusion and inject molding. The increase in the biocompatibility and relatively high mechanical properties render OPLA-ESOA-HAP/PLLA a potential material for the biodegradable fixation system.

High vinyl polybutadiene (HVPB) liquid rubber has extensive applications in multiple fields, such as rubber, coatings, and adhesives. Quantitative functionalization modification of polybutadiene will further expand its application scope. In this paper, a classic living anionic polymerization (LAP) method was adopted, using 1,2-bis(4-ethylpiperazin-1-yl)ethane (BEPE) as a novel modifier, n-butyllithium as an initiator, and N,N-dimethylvinylbenzylamine as a functional monomer. Through an in situ copolymerization mode, the quantitative and chain-middle/end positioning introduction of tertiary amine functional groups was achieved, and a series of highly vinyl-functionalized polybutadiene (f-HVPB) liquid rubbers with controlled molecular weights and narrow molecular weight distributions were prepared. On the other hand, m-chloroperbenzoic acid was used as an epoxidizing agent to quantitatively epoxidize liquid high-vinyl polybutadiene and functionalized polybutadiene to prepare side-chain highly epoxy/tertiary amine bifunctional polybutadiene (bf-HVPB) products. The effects of different reaction systems, including different solvents, different epoxidizing agent ratios, different temperatures, different molecular weights, and amine modification, on the epoxidation of HVPB and f-HVPB were mainly investigated. The fine structures of the polymerization products were systematically analyzed by 1H NMR, FTIR, DSC, and GPC.

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@Al₂O₃) 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 = fhSSPS) multiblock copolymers containing strictly VCH-alt-EP alternating sequences and with narrow Đ _Ms 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, H₂ 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 fhSSPS.