The doubly thermo-responsive triblock copolymer nanoparticles of polystyrene-block-poly(N-isopropylacrylamide)-block-poly[N,N-(dimethylamino) ethyl methacrylate] (PS-b-PNIPAM-b-PDMAEMA) are successfully prepared through the seeded RAFT polymerization in situ by using the PS-b-PNIPAM-TTC diblock copolymer nanoparticles as the seed. The seeded RAFT polymerization undergoes a pseudo-first-order kinetics procedure, and the molecular weight increases with the monomer conversion linearly. The hydrodynamic diameter (Dh) of the triblock copolymer nanoparticles increases with the extension of the PDMAEMA block. In addition, the double thermo-response behavior of the PS-b-PNIPAM-b-PDMAEMA nanoparticles is detected by turbidity analysis, temperature-dependent 1H-NMR analysis, and DLS analysis. The seeded RAFT polymerization is believed as a valid method to prepare triblock copolymer nanoparticles containing two thermo-responsive blocks. 相似文献
Block copolymers (BCPs) can automatically assemble into various regulated nanoparticles when they are confined within the emulsion droplet because of the structural frustration of polymer chains and the soft template effect of the oil/water interface. In the past few years, great efforts have been made to regulate the morphologies of the resulting BCP particles. In this review article, various strategies for tuning oil/water interfacial properties to engineer the as-formed BCP particles were summarized. Then, the comprehensive scenarios of the applications of the resulting BCP particles were discussed. Finally, the future tendency and challenge of the self-assembly of BCPs confined in emulsion droplet were suggested. 相似文献
Chemoselective stepwise coupling between living polymers and a heterobifunctional linking agent is shown to be a versatile, facile, and efficient methodology for block copolymer synthesis. This protocol is based on the quantitative formation of the end‐functionalized precursor in the first coupling step. In this proof‐of‐concept study, we investigate the behavior of specific macroanions, prepared through living anionic polymerization (LAP). Nevertheless, the applicability range is becoming exceptionally wide upon transformation reactions, e.g., by tailoring the chain‐termini nucleophilicity via endcapping. This novel protocol will considerably expand the limits of LAP, rendering viable the construction of advanced and tailor‐made materials via an effortless pathway.
The synthesis of hybrid bioconjugates via the ring‐opening polymerization (ROP) of N‐carboxyanhydrides (NCAs) using a synthetic macroinitiator is described. Poly(n‐butyl acrylate), polystyrene, and poly(N‐isopropyl acrylamide) are synthesized (polydisperity index, Đ < 1.1) using reversible addition–fragmentation chain transfer (RAFT) as the synthetic tool. A phthalimidomethyl trithiocarbonate RAFT chain transfer agent is used to prepare well‐defined, end‐functional polymers, which after deprotection result in amine terminal macroinitiators. The subsequent initiating systems could successfully be chain extended with ε‐benzyloxycarbonyl‐l ‐lysine or γ‐benzyl‐l ‐glutamate as the NCAs to produce a library of polymer–polypeptide conjugates. In doing so, a novel procedure for directly synthesizing bioconjugates via a non‐modular route without the need for excessive purification and isolation steps is described.
Poly(styrene-b-isobutylene-b-styrene) triblock copolymer(SIBS), a kind of thermoplastic elastomer with biocompatibility and biostability containing fully saturated soft segments, could be synthesized via living cationic copolymerization. A novel poly[(styrene-comethylstyrene)-b-isobutylene-b-(styrene-co-methylstyrene)]-g-polytetrahydrofuran(M-SIBS-g-PTHF) block graft copolymer was prepared to increase the polarity and service temperature of SIBS by grafting polar PTHF segments onto SIBS. A serie... 相似文献
Block copolymers consisting of a pentafluorostyrene (PFS) block and a hydrophilic block were synthesized by RAFT polymerisation. The hydrophilic blocks consist of methacrylate derivatives, 4-hydroxystyrene or 4-vinylpyridine monomers. The block copolymers were obtained with narrow molecular weight distributions and the molecular weights were in good agreement with the theoretical values. In addition, a model thiol was reacted with the PFS moieties of the block copolymers. This polymer–analogous reaction was performed under ambient conditions in high yields resulting quantitatively in para-substitution of the pentafluorophenyl rings. Finally, thin films consisting of block copolymers that showed strong phase-segregation behaviour and ordered nanostructured surfaces consisting of both blocks were obtained. 相似文献
