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Graft copolymers have unique application scenarios in the field of high-performance thermoplastic elastomers, resins and rubbers. β-myrcene (My) is a biomass monomer derived from renewable plant resources, and its homopolymer has a low glass transition temperature and high elasticity. In this work, a series of tapered copolymers P(My- co -AMS) k (k = 1, 2, 3) were first synthesized in cyclohexane by one-pot anionic polymerization of My and α-methyl styrene (AMS) using sec-BuLi as the initiator. PAMS chain would fracture when heated at high temperature and could endow the copolymer with thermal degradation property. The effect of the incorporation of AMS unit on the thermal stability and glass transition temperature of polymyrcene main chain was studied. Subsequently, the double bonds in the linear copolymers were partially epoxidized and hydroxylated into hydroxyl groups to obtain hydroxylated copolymer, which was finally used to initiate the ring-opening polymerization (ROP) of ε-caprolactone (ε-CL) to synthesize the graft copolymer with PCL as the side chain. All these copolymers before and after modifications were characterized by proton nuclear magnetic resonance ( 1 H NMR), gel permeation chromatography (GPC), thermogravimetry analysis (TGA), and differential scanning calorimeter (DSC).

We report the first anionic polymerization of 1-vinylcyclohexene (VCH). This structure may be considered as an intermediate between dienes and styrene. The polymerization of this cyclic 1,2-disubstituted 1,3-diene proceeded quantitatively in cyclohexane at 25 °C with sec-butyllithium as an initiator. The obtained polymers have well-controlled molecular weights in the range of 5 to 142 kg mol -1 , controlled by the molar ratio of monomer and initiator, with narrow molecular weight distributions (Đ<1.07-1.20). In situ 1 H NMR kinetic characterization revealed a weak gradient structure for the copolymers of styrene and VCH, (r Sty =2.55, r VCH =0.39). P(VCH) obtained in cyclohexane with sec-BuLi as an initiator showed both 1,4- and 3,4-incorporation mode (ratio: 64 : 36). It was demonstrated that the microstructure of the resulting P(VCH) can be altered by the addition of a modifier (THF), resulting in increasing 3,4-microstructure (up to 78 %) and elevated glass-transition temperature up to 89 °C. Thus, the monomer VCH polymerizes carbanionically like a diene, however leading to rigid polymers with high glass transition temperature, which provides interesting options for combination with other dienes to well-defined polymer architectures and materials., (© 2023 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

Liquid crystalline block copolymers (LCBCPs) are promising for developing functional materials owing to an assembly of better functionalities. Taking advantage of differences in reactivity between alkynyl and vinyl over temperature during hydrosilylation, a series of LCBCPs with modular functionalization of the block copolymers (BCPs) are reported by independently and site-selectively attaching azobenzene moieties containing alkynyl (LC 1 ) and Si-H (LC 2 ) terminals into well-designed poly(styrene)-block-polybutadienes (PS-b-PBs) and poly(4-vinylphenyldimethylsilane)-block-polybutadienes (PVPDMS-b-PBs) produced from living anionic polymerization (LAP). By the principle of modular functionalization, it is demonstrated that mono-functionalized (PVPDMS-g-LC 1 )-b-PB and PS-b-(PB-g-LC 2 ) not only maintain independence but also have cooperative contributions to bi-functionalized (PVPDMS-g-LC 1 )-b-(PB-g-LC 2 ) in terms of mesomorphic performances and microphase separation, which is evident from differential scanning calorimetry (DSC) and polarized optical morphologies (POM) and identified by powder X-ray diffractions. With the application of the new principle of modular functionalization, local-crosslinked liquid crystalline networks (LCNs) with controlled functionality are successfully synthesized, which show well-controlled phase behaviors over molecular compositions., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Reported is an intriguing advance in living anionic polymerization (LAP) by a "locked-unlocked" mechanism in which the living anionic species can be quantitatively locked by end-capping with 1-(tri-isopropoxymethylsilylphenyl)-1-phenylethylene (DPE-Si(O-iPr) 3 ) and can be unlocked by adding the key, sodium 2,3-dimethylpentan-3-olate (NaODP). These new insights into this mechanism were carefully confirmed by designing reactions involving sequential feeding of quantitative DPE-Si(O-iPr) 3 and traditional monomers mixed with NaODP, and subsequently characterizing the corresponding samples, taken during the feeding process, by GPC, NMR, and MALDI-TOF-MS techniques. The switch from the locked to unlocked state was clearly confirmed by these characterization techniques. The putative locked-unlocked mechanism in the LAP was simulated by the Gaussian method. This intriguing mechanistic finding of LAP reactions is expected to supplement the existing knowledge and facilitate the tailoring of specific structures for these polymerizations., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

This article reviews the development of a novel all-around iterative methodology combining living anionic polymerization with specially designed linking chemistry for macromolecular architecture syntheses. The methodology is designed in such a way that the same reaction site is always regenerated after the polymer chain is introduced in each reaction sequence, and this "polymer chain introduction and regeneration of the same reaction site" sequence is repeatable. Accordingly, the polymer chain can be successively and, in principle, limitlessly introduced to construct macromolecular architectures. With this iterative methodology, a variety of synthetically difficult macromolecular architectures, i.e., multicomponent μ-star polymers, high generation dendrimer-like hyperbranched polymers, exactly defined graft polymers, and multiblock polymers having more than three blocks, were successfully synthesized., Competing Interests: The authors declare no conflict of interest.

By combining living anionic polymerization and the highly efficient Ugi four-component reaction (Ugi-4CR), in-chain, multicomponent, functionalized polymers are facilely synthesized with efficient conversation and abundant functionality. l-[4-[N,N-Bis(trimethylsilyl)-amino]phenyl]-l-phenylethylene, which is redefined as Ugi-DPE, is anionically copolymerized to synthesize the well-defined in-chain, multi-amino functionalized polystyrene (P(St/DPE-NH 2 )), the backbone for the Ugi-4CR, via hydrolysis of the copolymerization (P(St/Ugi-DPE)). Subsequently, several functionalized components are facilely clicked onto P(St/DPE-NH 2 ) to investigate the model reactions of the in-chain, multicomponent functionalization via the Ugi-4CR. In contrast to conventional postpolymerization modifications, this approach proceeds under mild reaction conditions without the use of a catalyst and meanwhile an efficient conversation is obtained. Finally, the modified experimental results investigated in this research show the promising potential of the combination of well-defined amino functionalized polymers and Ugi-4CR in the field of multicomponent, functionalized postpolymerization modification., (© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A 1,1-diphenylethylene (DPE) derivative with an alkoxysilyl group (DPE-SiOEt) was synthesized. It was end-capped with poly(styryl)lithium (PSLi) and then copolymerized with styrene via living anionic polymerization (LAP) in a non-polar solvent at room temperature. The observed side coupling reaction was carefully investigated by end-capping the polymer. Changes in molecular weight support the plausibility of a mechanism involving living anionic species (PSLi or lithiated DPE-end-capped polystyrene, PSDLi) and the alkoxysilyl groups. Through a series of copolymerizations with different feed ratios, the kinetics of the side coupling reaction were also studied. The results showed that the side reactions could be controlled using an excess feed of DPE-SiOEt, a potentially useful strategy for the synthesis and application of well-defined alkoxysilyl-functionalized polymers via LAP., Competing Interests: The authors declare no conflict of interest.

Well-controlled anionic polymerization of an initiator-functionalized monomer, p -(2,2'-diphenylethyl)styrene (DPES), was achieved for the first time. The polymerization was performed in a mixed solvent of cyclohexane and tetrahydrofuran (THF) at 40 °C with n -BuLi as initiator. When the volume ratio of cyclohexane to THF was 20, the anionic polymerization of DPES showed living polymerization characteristics, and well-defined block copolymer PDPES- b -PS was successfully synthesized. Furthermore, radical polymerization of methyl methacrylate in the presence of PDPES effectively afforded a graft copolymer composed of a polystyrene backbone and poly(methyl methacrylate) branches. The designation of analogous monomers and polymers was of great significance to synthesize a variety of sophisticated copolymer and functionalize polymer materials.

Two DendriMac polymers (Dendri-hydr and Dendri-click) are efficiently and conveniently synthesized via the combination of living anionic polymerization (LAP) and hydrosilylation/click chemistry. Based on the end-capping of DPE derivatives (DPE-SiH and DPE-DA) toward polymeric anions, the polymeric core and arms are effectively synthesized, and the base polymers can be regarded as polymeric bricks. Hydrosilylation and click chemistry are used as coupling reactions to construct the DendriMac polymers with high efficiency and convenience. The numbers of branched arms are calculated by SEC as 5.84 and 6.08 for Dendri-hydr and Dendri-click, respectively, which indicate that the DendriMac architectures exhibit high structural integrity. Because of its independence, high efficiency, and convenience, the whole construction can be regarded as the "building of polymeric bricks.", (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

By combining living anionic polymerization and hydrosilylation, densely grafted bottlebrush polymers with controlled spacing of branch points are prepared. Dimethyl(4-vinylphenyl)silane and dimethyl(4-(1-phenylvinyl)phenyl)silane are anionically (co)polymerized to synthesize uniform, alternating, and gradient in-chain silyl-hydride (Si-H) functionalized backbones. The spacing of branch points is controlled effectively by regulating the distribution of Si-H groups along the backbones. Three backbones with a similar number of Si-H groups but variable distributions are used to synthesize corresponding bottlebrush polymers via hydrosilylation between the backbones and chain-end vinyl functionalized polystyrene. The uniformly grafted bottlebrush exhibits the highest hydrodynamic radius (Rh ) of 5.6 nm and the lowest Tg of 79 °C which may be attributed to its compact grafted structure. This methodology exhibits high efficiency and convenience for the construction of bottlebrushes with controlled distribution of brushes., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)