alpha-(Aminomethyl)acrylate: polymerization and spontaneous post-polymerization modification of beta-amino acid ester for a pH/temperature-responsive material

First published online 16 Jun 2015Ethyl α-(aminomethyl)acrylate, a β-amino acid ester carrying a conjugated vinylidene group at the α-position, was radically polymerized. The polymerization was found to involve subsequent ester–amide exchange reaction between the amino pendants of the polymer and an ester group of the monomer, affording acrylamide-bearing units in 11–15% contents. The obtained polymer exhibited pH/temperature responsiveness in aqueous media.ArticlePOLYMER CHEMISTRY. 6(28):5026-5029 (2015)journal articl

Stereospecific Anionic Polymerization of α-(Hydroxymethyl)acrylate with Protective Group

Anionic polymerizations of hydroxyl-protected α-(hydroxymethyl)acrylates were investigated. The methyl ester with methoxymethyl (1-MOM) and allyl (1-allyl) protecting groups were polymerized by isopropyl α-lithioisobutyrate (Li-iPrIB) in toluene at −78 °C, affording highly isotactic polymers. Similarly, the polymerization of ethyl ester (2-MOM) gave an isotactic polymer, while those of t-butyl (3-MOM) and isobutyl (4-MOM) ester did not form any polymeric products. The hydrolysis of poly(2-MOM) in acidic conditions resulted in the deprotection of MOM group, although the acid also catalyzed the ester exchange between the neighboring units to form lactone units, as observed by 1H NMR analysis, IR spectroscopy and thermogravimetric analysis. A film of poly(2-MOM) exposed to HCl vapor for 2 h became insoluble in any organic solvents due to the lactonization in solid state.ArticleMacromolecular Symposia.350(1):86-98(2015)journal articl

Termination of Living Anionic Polymerization of Butyl Acrylate with alpha-(Chloromethyl) acrylate for End-Functionalization and Application to the Evaluation of Monomer Reactivity

Article first published online: 11 JUN 2015Anionic polymerization of n-butyl acrylate (nBA) in toluene initiated with a binary initiator, isopropyl α-lithioisobutyrate/ethylaluminum bis(2,6-di-tert-butylphenoxide) at −60 °C, is terminated with ethyl α-(chloromethyl)acrylate (ECMA) to afford a poly(nBA) possessing an acryloyl group at the terminal with 80% of termination efficiency. The reactivity of nBA against a polymer anion of methyl methacrylate formed under identical conditions is estimated relative to the termination with ECMA by reacting a mixture of nBA and ECMA followed by 1H NMR spectroscopic chain-end analysis; the relative reactivity of nBA is found 80 times or more higher than ECMA.ArticleMACROMOLECULAR CHEMISTRY AND PHYSICS. 216(14):1534-1539 (2015)journal articl

Stereoregular poly (methyl methacrylate) with double-clickable ω-end: synthesis and click reaction

Isotactic and syndiotactic poly(methyl methacrylate)s with orthogonally double-clickable terminal ends, that is, α,β-unsaturated esters for Michael addition-type thiol–ene reactions and azide or alkynyl groups for azide–alkyne click reactions, were prepared via a terminating reaction of stereospecific anionic polymerization with propargyl and 2-chloroethyl α-(chloromethyl)acrylates. The subsequent polymer modification via a double click reaction proceeded quantitatively in a one-pot system under ambient conditions. The facile and almost quantitative double-end-functionalization would open a new material design based on stereoregular PMMAs with controlled molecular weights.ArticlePolymer Chemistry.6(19):3601-3607(2015)journal articl

Synthesis and post-polymerization reaction of end-clickable stereoregular polymethacrylates via termination of stereospecific living anionic polymerization

Poly(methyl methacrylate)s with high stereoregularity and clickable end-groups were synthesized via terminating reactions with α-(halomethyl)acrylates in stereospecific living anionic polymerization. The terminating reaction was efficient and tolerant to the reaction conditions to such an extent that almost quantitative end-functionalization was achieved in isotactic- and syndiotactic-specific polymerization systems. The terminating reactions were also achieved in polymerizations of vinyl methacrylate and trimethylsilyl methacrylate. For the polymerization of butyl acrylate, however, the termination efficiency was limited to less than 69%. Furthermore, the quantitative end-functionalization of the incorporated C[double bond, length as m-dash]C double bond at ω-end was achieved with various thiols catalyzed by Et3N. The base-catalysed thiol–ene reaction of the stereoregular poly(vinyl methacrylate) with a ω-end C[double bond, length as m-dash]C double bond selectively proceeded to retain vinyl ester functions, and the subsequent hydrolysis afforded ω-functional stereoregular poly(methacrylic acid). A combination of the terminating agent with a protected lithium amide afforded stereoregular poly(methyl methacrylates) with orthogonally clickable α- and ω-ends.ArticlePolymer Chemistry.6(7):1078-1087(2015)journal articl

α-exomethylene lactone possessing acetal–ester linkage: Polymerization and postpolymerization modification for water-soluble polymer

First published: 16 October 20152,6-Dimethyl-5-methylene-1,3-dioxa-4-one (DMDO), a cyclic acrylate possessing acetal–ester linkage, was obtained as a mixture of cis- and trans-isomers (95:5) from Baylis–Hillman reaction of an aryl acrylate. The radical and anionic polymerizations of DMDO yielded the corresponding vinyl polymers without any side reactions such as cleavage of the acetal–ester linkage. The polymerization behaviors were significantly different from that of the acyclic acrylate, α-(hydroxymethyl)acrylic acid, which was expected inactive against polymerization due to the steric hindrance around the vinylidene group by the α-substituent. The acetal–ester linkage of the obtained polymer (P1) was completely cleaved via acid hydrolysis to afford a water soluble polymer, P2. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 955–961ArticleJournal of Polymer Science Part A: Polymer Chemistry. 54(7):955-961 (2016)journal articl

Source-based nomenclature for single-strand homopolymers and copolymers (IUPAC Recommendations 2016)

IUPAC recommendations on source-based nomenclature for single-strand polymers have so far addressed its application mainly to copolymers, non-linear polymers and polymer assemblies, and within generic source-based nomenclature of polymers. In this document, rules are formulated for devising a satisfactory source-based name for a polymer, whether homopolymer or copolymer, which are as clear and rigorous as possible. Thus, the source-based system for naming polymers is presented in a totality that serves as a user-friendly alternative to the structure-based system of polymer nomenclature. In addition, because of their widespread and established use, recommendations for the use of traditional names of polymers are also elaborated