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In this work, poly(α-methyl styrene) (PAMS) was synthesized through living anionic polymerization and characterized by 13C NMR, 1H NMR, GPC, TGA, DSC. The kinetics study was performed using multi-stage dosing of initiator. The results obtained via GPC analysis revealed that polydispersity index of the synthesized PAMS was close to the true value. Moreover, multi-stage dosing of initiator offers valuable and accurate method to determine propagation rate constant and initial impurities value of the system. 13C NMR analysis demonstrated that Bernoullian statics model exhibits a superior fit compared to 1st -order Markov statics model for the assigned sequence. Furthermore, the synthesized PAMS presents higher degree of racemic addition with Pm=0.439. 1H NMR spectroscopy was utilized to ascertain number-average molecular weight of the synthesized samples, corroborating the values estimated through GPC analysis. From the thermal analysis, it was shown that PAMS containing very low molecular weight demonstrates negative glass transition temperature and broad thermal decomposition range. [ABSTRACT FROM AUTHOR]

This article reviews the various developments of a new methodology combining the living anionic polymerization and a designed linking chemistry for the synthesis of block polymers using two, two of three, three, or four monomers with different reactivities. With this methodology, a number of well-defined triblock copolymers, triblock terpolymers, tetrablock quaterpolymers, and multiblock copolymers with alternating two segments have been successfully synthesized. The obtained polymers were all novel well-defined block polymers with unusual block sequences. More importantly, they are definitely inaccessible by the sequential polymerization using monomers with different reactivities. The monomers used in the synthesis were mainly styrene, 2-vinylpyridine, and methyl (or tert-butyl) methacrylate classified into three categories by their reactivities. In addition, 1,2-butylene oxide was used as the fourth monomer to synthesize the tetrablock quaterpolymers. There are also a number of other monomers classified into each of these categories, which can be readily replaced from the main monomers. By developing the methodology using these monomers, it becomes possible to synthesize a far more number of block polymers beyond our imagination. In practice, several synthetic feasibilities are described in each chapter. The key for this synthetic success is to suitably choose an α-phenylacrylate function used as the reaction site, capable of quantitatively linking with each of the living anionic polymers having a wide range of reactivity, which makes it possible to connect two different polymer segments difficult to access by the sequential polymerization. One more important issue is to employ the iterative linking process, which enables the successive synthesis of alternating multiblock copolymers of up to the decablock type and possibly with more blocks. Generality, versatility, and advantages of the proposed methodology have been demonstrated throughout the synthesis of the block polymers. [ABSTRACT FROM AUTHOR]

We report here a method for the preparation of amphiphilic dendrimer-like copolymers with dendritic polystyrene (PS) core and protonated poly(2-vinyl pyridine) (P2VP) or poly(methacrylic acid) (PMAA) shell. The method employed the efficient coupling reaction of anionic living polymer chains and chlorosilane. The synthesis started from a functionalized 3rd generation dendritic polystyrene, G3PS-g-SiCl, used as the precursor. The dendrimer-like copolymer of styrene and 2-vinyl pyridine, G3PS-g-P2VP, was synthesized by direct coupling of living P2VPLi to the precursor. The dendrimer-like copolymer of styrene and tert-butyl methacrylate, G3PS-g-PtBMA, was synthesized by an indirect procedure in which a living polymer containing mainly PtBMA segment was attached to the precursor. Both methods resulted in the formation of dendrimer-like copolymers with the high molecular weights (up to 8.5 × 106 Da), large molecular sizes (diameter up to 73 nm), and dense shells (number of arms up to 1300). These products, G3PS-g-P2VP and G3PS-g-PtBMA, were protonated with trifluoroacetic acid and acidic hydrolyzed, respectively. After transformation, amphiphilic dendrimer-like copolymers, G3PS-g-P2VPH+ and G3PS-g-PMAA, were obtained. Preliminary results on the solution properties of the amphiphilic products were presented. [ABSTRACT FROM AUTHOR]

"Thiol-yne" click reaction has already been widely applied in synthesis and modification of new polymer structures or novel materials due to its specific features. However, in most studies, only chain-end strategy was employed when using the di-addition feature of thiol-yne reaction, thus the in-chain di-addition strategy could endow us with a broader space to develop the synthesis of advanced polymers. Therefore, in this paper, the features of in-chain mono- and di-addition were investigated when modifying the alkyne-functionalized polymers to prepare grafted polymers via thiol-yne click reaction. The results showed that it is almost impossible to obtain the in-chain di-adducts even under excess feeding of chain-end thiol-functionalized grafts, while only the in-chain mono-adducts could be obtained efficiently. Further researches investigated that the controlled grafting could be encountered when carrying out the thiol-yne click reaction between chain-end alkyne-functionalized polystyrenes and chain-end thiol-functionalized polystyrenes under proper feedings. Therefore, the effect of steric-hindrance might be the primary reason for the alternative grafting via thiol-yne click reaction between in-chain and chain-end alkyne-functionalized polymers. [ABSTRACT FROM AUTHOR]

Block copolymers containing polytetrahydrofuran segments were synthesized by umpolung or propagating end of the cationic living polymer and successive anionic polymerization of methacrylates (RMAs) or radical polymerization of RMAs, acrylonitrile (AN), and styrene (St). Living polytetrahydrofuran (poly-THF) was prepared by cationic polymerization of tetrahydrofuran (THF), whose propagation end was reduced by samarium(II) iodide (SmI2). Anionic polymerizations of RMAs were conducted by addition of the monomers to the reduced poly-THF to obtain poly(THF-b-RMAs). On the other hand, the 2-bromoisobutyrate group, which can act as an initiator of radical polymerization, was introduced to the cationic propagating end of poly-THF by adding sodium 2-bromoisobutyrate. Block copolymers were synthesized by living radical polymerization of RMAs, St, or AN using the 2-bromoisobutyrate-capped poly-THF as a macroinitiator and copper(I) bromide (CuBr) as a catalyst. [ABSTRACT FROM AUTHOR]

A novel convenient dual-side initiator of lutidine dianion for anionic polymerization has been investigated in terms of their initiation and propagation kinetics. This lutidine dianion could be synthesized in quantitative yields reacting commercial products of 2,6-lutidine with sec-butyl lithium without any complex organic synthesis, and could be used effectively as the dual-side initiator to synthesize polyisoprene with various molecular weights via living anionic polymerization. In addition, this lutidine dianion can produce 50% of 1.4-microstructure contents in polyisoprene which is very important for elastomeric property of polydienes. All experimental evidences showed the living property and were consistent with quantitative yields without any side reactions when the anionic living polymerization proceeded using lutidine dianion as the initiator. [ABSTRACT FROM AUTHOR]

Poly(ethylene oxide) (PEO) was controllably grafted from styrene-b-(ethylene-co-propylene)-b-styrene (SEPS) backbones by combining lithiation of styrenic units and living monomer-activated anionic ring-opening polymerization of ethylene oxide (EO) monomers with the aid of co-initiators triisobutyl aluminum. The as-synthesized SEPS-g-PEO copolymers were characterized by SEC, 1H-NMR, FTIR, SAXS, AFM and DSC. When the branch length is relatively small, increase of PEO fraction leads to the increase of the correlation length between neighboring hard domains, but the degree of correlation reduces. When the branch length is relatively large, the phase-separated structures become random both in terms of size and spatial correlation, and macro-phase separated structures appear. The crystallization behavior of the PEO branches can be effectively inhibited in SEPS-g-PEO, so no significant crystallization takes place until the fraction of PEO branches is 20.1 wt%, which greatly promotes the rapid delivery of hydrophilic drugs in the hot-melting pressuresensitive adhesives (HMPSAs) based on SEPS-g-PEO. Their cumulative release amount of a model drug could achieve 80%, more than twice the value in the HMPSAs based on linear PEO-containing styrenic block copolymers. [ABSTRACT FROM AUTHOR]

Anionic polymerizations of 2-(ethoxy)ethyl methacrylate (EOEMA) were carried out under several conditions that allowed for living polymerization of methyl methacrylate (MMA). It was found that the polymerization rate of EOEMA by t-CHMgBr in toluene was much lower than that of MMA under these conditions. However, the polymerization rate of EOEMA by t-CHMgBr in tetrahydrofuran was not much lower than the polymerization of MMA. Interactions between the counter cation (magnesium) and the ether oxygen of the ester moiety in the EOEMA unit are considered important to delay the polymerization. Random and block copolymerizations of EOEMA and MMA by t-CHMgBr in toluene were also carried out and the results support the interaction of ether oxygen. 4-(Ethoxy)butyl methacrylate (EOBMA) was successfully prepared from 4-ethoxy-1-butanol and methacryloyl chloride and purified. Polymerization of EOBMA with t-CHMgBr in toluene provides a polymer with good yield, suggesting that the number of carbon atoms between the ester group and the ether oxygen is important to the interactions with the ether oxygen. Some of the thermal properties of the polymers and copolymers, including their glass transition temperature and thermal stability, were also evaluated. [ABSTRACT FROM AUTHOR]

Three-arm and four-arm star-like polybutadienes (PBds) were synthesized via the combination of living anionic polymerization and the click coupling method. Kinetic study showed that the click reaction between the azido group terminated PBd-t-N and the alkyne-containing multifunctional linking reagent was fast and highly efficient. All coupling reactions were fully accomplished within 40 min at 50 °C in toluene in the presence of the reducing agent Cu(0), proven by H-NMR, FTIR and GPC measurements. For the coupling reactions between the PBd-t-N polymer and dialkyne-containing compound, the final conversion of the coupled PBd-PBd polymer was ca. 97.0%. When a PBd-t-N polymer was reacted with trialkyne-containing or tetraalkyne-containing compound, the conversion of three-arm or four-arm PBd was around 95.5% or 87.0%, respectively. Several factors influencing the coupling efficiency were studied, including the molecular weight of the initial PBd-t-N, arm numbers and the molar ratio of the azido group to the alkynyl group. The results indicated that the conversion of the target products would be promoted when the molecular weight of the PBd-t-N was low and the molar ratio of the azido to alkynyl groups was close to 1. [ABSTRACT FROM AUTHOR]

An unsymmetrical triphenylethane, ethane-1,1,2-triyltribenzene (ETB), was successfully prepared from phenyl lithium, trans-1,2-diphenylethylene, and methanol. Characterization of the compound was performed by H and C nuclear magnetic resonance spectroscopy (NMR). The polymerization of methyl methacrylate (MMA) was performed in the presence of ETB at 85 °C or higher. The free radicals obtained were characterized by ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF MS). Gel permeation chromatography (GPC) traces of the average molecular weight of poly(MMA) (PMMA) showed a series of translations with increasing time. The average molecular weight of PMMA indicated narrow polydispersity, and a linear relationship was found between ln([M]/[M]) and polymerization time. These results indicated the 'living' nature of the polymerization of MMA in the presence of ETB. The structure of ETB was also introduced to the end of polystyrene (PS), polyisoprene (PI), and polyisoprene- b-polystyrene (PIS) chains which were obtained by living anionic polymerization. Hence, they initiated radical polymerization of MMA as ETB- end-macroinitiators to obtain block copolymers. Thus, living anionic polymerization and this radical polymerization method were combined together to prepare block copolymers without the intermediate transformation step. [ABSTRACT FROM AUTHOR]

'Click chemistry' is, by definition, a general functionalization methodology (GFM) and its marriage with living anionic polymerization is particularly powerful in precise macromolecular synthesis. This paper reports the synthesis of a 'clickable' middle-chain azide-functionalized polystyrene (mPS-N) by anionic polymerization and its application in the preparation of novel shape amphiphiles based on polyhedral oligomeric silsesquioxane (POSS). The mPS-N was synthesized by coupling living poly(styryl)lithium chains (PSLi) with 3-chloropropylmethyldichlorosilane and subsequent nucleophilic substitution of the chloro group in the presence of sodium azide. Excess PSLi was end-capped with ethylene oxide to facilitate its removal by flash chromatography. The mPS-N was then derived into a giant lipid-like shape amphiphile in two steps following a sequential 'click' strategy. The copper(I)-catalyzed azide-alkyne cycloaddition between mPS-N and alkyne-functionalized vinyl-substituted POSS derivative (VPOSS-alkyne) ensured quantitative ligation to give polystyrene with VPOSS tethered at the middle of the chain (mPS-VPOSS). The thiol-ene reaction with 1-thioglycerol transforms the vinyl groups on the POSS periphery to hydroxyls, resulting in an amphiphilic shape amphiphile, mPS-DPOSS. This synthetic approach is highly efficient and modular. It demonstrates the 'click' philosophy of facile complex molecule construction from a library of simple building blocks and also suggests that mPS-N can be used as a versatile 'clickable' motif in polymer science for the precise synthesis of complex macromolecules. [ABSTRACT FROM AUTHOR]

A well-defined amphiphilic centipede-like copolymer of styrene and methacrylic acid (PS-PS-PMAA) was synthesized by the combination of living anionic polymerization and atom transfer radical polymerization (ATRP). The synthetic approach involves the first coupling reaction of polystyrene (PS) backbone bearing 1,1-diphenylethene (DPE) pendant groups with living polystyryllithium (PSLi), and sequential anionic polymerization of t-butyl methacrylate ( tBMA) initiated by resulting 1,1-diphenylmethyl anion, and final hydrolysis of obtained PS-PS-P tBMA. The centipede-like copolymer PS-PS-PMAA was characterized by H NMR, IR, GPC, and SLS measurements. The critical micelle concentration (CMC) of PS-PS-PMAA in water was determined by fluorescence probe technique. The self-assembly behavior of PS-PS-PMAA in water-THF mixture was observed by TEM. The results showed that the micellar morphology can be varied, such as vesicle, sphere, and agglomerate, depending on the THF content. These phenomena are worthy of further research in polymer physics field. [ABSTRACT FROM AUTHOR]

The precise synthesis of novel ferrocene-based regular and asymmetric star-branched polymers by a methodology using specially designed 1,1-diphenylethylene derivatives in conjunction with living anionic polymerization of ferrocenylmethyl methacrylate (FMMA) is described. The methodology involves three reaction steps, i.e., (1) introduction of 3-( tert-butyldimethylsilyloxymethyl)phenyl (SMOP) group(s) at the polymer chain end or in-chain, (2) conversion of the SMOP group(s) to α-phenyl acrylate function(s), and (3) a linking reaction of the α-phenyl acrylate function(s) with the living anionic polymer of FMMA or methyl methacrylate. By developing this methodology, a variety of 3-arm $$ {\text{AA}^{\prime}_{2}} $$, AB, AB, ABC and 4-arm A, AB, AB, ABC, and ABC star-branched polymers with well-defined structures have been successfully synthesized. The A, B, and C segments are poly(FMMA), polystyrene, and poly(methyl methacrylate), respectively. [ABSTRACT FROM AUTHOR]

novel well-defined comb-like ionomer with cations was synthesized by the combination of living anionic polymerization and atom transfer radical polymerization (ATRP). The synthetic approach involves the coupling reaction of polystyrene (PS) backbone bearing 1,1-diphenylethene (DPE) pendant groups with living polystyryllithium (PSLi), subsequent amine functionalization of the resulting 1,1-diphenylmethyl anions with 3-dimethylaminopropyl chloride (DMAPC), and quaternization of tertiary amino groups with hydrochloric acid. The comb-like ionomer was characterized by H NMR, IR, GPC measurements and end-group titrition. [ABSTRACT FROM AUTHOR]

Well-defined comb-like branched polymers having one branch in each repeating unit have been successfully synthesized by the coupling reaction of living polystyrene (PS) and polyisoprene (PI) anions with 1, 1-diphenylethenyl (DPE) groups along PS backbone prepared via atom transfer radical polymerization (ATRP) of 4-vinylbenzyloxy benzophenone (Sc) followed by Wittig reaction. The resulting comb-like branched polymers were characterized by IR, 1H-NMR, gel permeation chromatography (GPC) and static light scattering (SLS) in detail. The effect of living chains and DPE group molar ratio on grafting efficiency was discussed. The results show the coupling reaction of living chains and DPE groups was highly effective, and the coupling efficiency can be controlled via the feed molar ratios of living chains and DPE groups. Moreover, the effect of molecular weights of backbone (PSe) and PSLi or PILi on grafting efficiency was also discussed. The results show that when excess living polymers were used, the almost quantitative grafting efficiency could be achieved. [ABSTRACT FROM AUTHOR]

The subject of this review is to introduce a novel iterative methodology based on living anionic polymerization using specially designed 1,1-diphenylethylene (DPE) derivatives recently developed for the synthesis of well-defined many armed star-branched polymers with same or chemically different arm segments. The methodology basically involves only two sets of the following reaction conditions for the entire iterative synthetic sequence: (a) a linking reaction of a living anionic polymer with a DPE-chain-functionalized polymer, and (b) an in situ reaction of a DPE-functionalized agent with the anion generated by the linking reaction to reintroduce the DPE functionality usable for the next reaction. The number of arms to be linked by each stage of the iteration depends on the starting core and DPE-functionalized agents and can dramatically increase by the agent of choice. New functional asymmetric star-branched polymers involving conductive and rigid rod-like poly(acetylene) segment(s) have been synthesized by the methodology using the intermediate polymer anions produced by the linking reaction as macroinitiators to polymerize 4-methylphenyl vinyl sulfoxide, followed by thermal treatment of the resulting star-branched polymers. [ABSTRACT FROM AUTHOR]

This article presents abstracts of the comprehensive papers submitted to the "Japanese Journal of Polymer Science and Technology." Some of the abstracts are as follows: "Novel Precision Cyclopolymerization of Dienes by Late Transition Metal Catalysts," by Daisuke Takeuchi and others; "Polymerization of Lactones and Lactides Initiated by Cyclodextrins," by Motofumi Osaki; "Precise Cross-Coupling Control During Oxidative Coupling Polymerization," by Shigeki Habaue; "Precise Synthesis of Functional Polymers by RAFT Polymerization," by Hideharu Mori and others.

A well-defined, A2B-type, centipede-like copolymer of styrene and methyl methacrylate (PS-PS-PMMA) was synthesized by the combination of living anionic polymerization and atom transfer radical polymerization (ATRP). The synthetic approach involves the coupling reaction of polystyrene (PS) backbone bearing 1,1-diphenylethene (DPE) pendant groups, produced by ATRP and Wittig reaction, with living polystyryllithium (PSLi), and subsequent polymerization of the resulting 1,1-diphenylmethyl anions with methy methacrylate. The centipede-like copolymer was characterized by 1H NMR, IR, SEC, SLS, and DSC measurements. [ABSTRACT FROM AUTHOR]

Living anionic and cationic polymerizations have been combined to prepare various types of comb-like copolymers composed of polystyrene (PS) and polyisoprene (PI) blocks, with a precisely controlled architecture. According to the relative placement of these elementary building blocks, combs with randomly distributed PS and PI or with poly(styrene- b-isoprene) diblock branches ( I & II, respectively) can be prepared. The reaction procedure initially includes the synthesis of a poly(chloroethylvinyl ether) using living cationic polymerization, which is used as the reactive backbone to successively graft PS-Li and PI-Li or PI- b-PS-Li to obtain structures ( I) or ( II). The synthesis of Janus-type PS-comb- b-PI-combs ( III) initially involves the synthesis of a diblock backbone using living cationic polymerization, which bears two distinct reactive functions having either a protected or activated form. Living PS-Li and PI-Li are then grafted, in two separate steps, onto each of the reactive functions of the backbone, respectively. [ABSTRACT FROM AUTHOR]

To successively synthesize star-branched polymers, we developed a new iterative methodology which involves only two sets of the reactions in each iterative process: (a) an addition reaction of DPE or DPE-functionalized polymer to a living anionic polymer, and (b) an in-situ reaction of 1-(4-(4-bromobutyl)phenyl) -1-phenylethylene with the generated 1,1-diphenylalkyl anion to introduce one DPE functionality. With this methodology, 3-, 4-, and 5-arm, regular star-branched polystyrenes, as well as 3-arm ABC, 4-arm ABCD, and a new 5-arm ABCDE, asymmetric star-branched polymers, were successively synthesized. The A, B, C, D, and E arm segments were poly(4-trimethylsilylstyrene), poly(4-methoxystyrene), poly(4-methylstyrene), polystyrene, and poly(4- tert-butyldimethylsilyloxystyrene), respectively. All of the resulting star-branched polymers were well-defined in architecture and precisely controlled in chain length, as confirmed by SEC,H NMR, VPO, and SLS analyses. Furthermore, we extended the iterative methodology by the use of a new functionalized DPE derivative, 1-(3-chloromethylphenyl)-1-((3-(1-phenylethenyl)phenyl)ethylene, capable of introducing two DPE functionalities via one DPE anion reaction site in the reaction (b). The number of arm segments of the star-branched polymer synthesized by the methodology could be dramatically increased to 2, 6, and up to 14 by repeating the iterative process. [ABSTRACT FROM AUTHOR]

Dendritic hyperbranched poly(methyl methacrylate)s (PMMA)s, whose branched architectures resemble the 'dendron' part(s) of dendrimer, were synthesized by an iterative methodology consisting of two reactions in each iteration process: (a) a coupling reaction of α-functionalized, living, anionic PMMA having two tert-butyldimethylsilyloxymethylphenyl (SMP) groups with benzyl bromide (BnBr)-chain-end-functionalized PMMA, and (b) a transformation reaction of the introduced SMP groups into BnBr functionalities. These two reactions, (a) and (b), were repeated three times to afford a series of dendron-like, hyperbranched (PMMA)s up to third generation. Three dendron-like, hyperbranched (PMMA)s different in branched architecture were also synthesized by the same iterative methodology using a low molecular weight, functionalized 1,1-diphenylalkyl anion prepared from sec-BuLi and 1,1-bis(3- tert-butyldime-thylsilyloxymethylphenyl)ethylene in the reaction step (b) in each iterative process. Furthermore, structurally similar, dendron-like, hyperbranched block copolymers could be successfully synthesized by the iterative methodology using α-functionalized, living, anionic poly(2-(perfluorobutyl) ethyl methacrylate) (PRfMA) in addition to α-functionalized, living PMMA. Accordingly, the resulting block copolymers were comprised of both PMMA and PRfMA segments with different sequential orders. After the block copolymers were cast into films and annealed, their surface structures were characterized by angle-dependent XPS and contact angle measurements. All three samples showed significant segregation and enrichment of PRfMA segments at the surfaces. [ABSTRACT FROM AUTHOR]