Radical copolymerization of alkyl cyclobutenecarboxylates fused with cycloaliphatic framework with alkyl (meth)acrylates

Radical copolymerization behavior of alkyl cyclobutenecarboxylate‐derivatives 4‐6 and related norbornene‐derived compounds 7–9 is described. A variety of alkyl cyclobutenecarboxylates fused with cycloaliphatic framework ( 4–6 ) were prepared by [2 + 2] cycloaddition of five, six, and eight‐membered cycloolefins with alkyl propiolates [alkyl = Me, 2‐hydroxyethyl, and 3‐γ‐butyrolactonyl (γ‐BL)]. The fused cyclobutenecarboxylates 4–6 were radically copolymerized with n‐butyl acrylate (nBA) to afford random copolymers, and terpolymerized with alkyl methacrylates with bulky ester groups [alkyl = γ‐BL and 3‐(3‐methyladamantyl)]. The cyclobutane‐containing bicyclic framework incorporated in the resulting polymer backbone contributes to raising T_g of resulting copolymers. Similar results were obtained when a mixture of related norbornene‐derived compounds were used as monomers with an apparently enhanced T_g‐raising effect in the copolymerization with nBA. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 2716–2724     

Sulfobetaine zwitterionomers based on n‐butyl acrylate and 2‐ethoxyethyl acrylate: Monomer synthesis and copolymerization behavior

New materials with potential applications for adhesives and coatings, based on copolymers containing zwitterionic pendent groups, were investigated. n‐Butyl acrylate and 2‐ethoxyethyl acrylate were copolymerized with a series of five zwitterionic sulfobetaine monomers. The structure of the monomers was varied in terms of the zwitterion intercharge spacing and the bulkiness of the alkyl substituents at the quaternary ammonium unit. Four of the five zwitterionic sulfobetaine methacrylate (SBM) monomers used in the study were synthesized. An evaluation of the reactivity ratios for the copolymer systems was performed with programs based on statistically sound techniques such as the error‐in‐variables model and the nonlinear‐least‐squares method. Reactivity ratio estimates for all 10 comonomer pairs were obtained, and they showed clear variations in reactivity with the structure of the SBM. In general, the more hydrophobic the SBM was, the lower its reactivity was with respect to the acrylate monomers. © 2002 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 511–523, 2002; DOI 10.1002/pola.10138     

Bis(β‐ketoamino)copper(II)/methylaluminoxane systems for homo‐ and copolymerizations of methyl acrylate and 1‐hexene

Two bis(β‐ketoamino)copper [ArNC(CH₃)CHC(CH₃)O]₂Cu ( 1 , Ar = 2,6‐dimethylphenyl; 2 , Ar = 2,6‐diisopropylphenyl) complexes were synthesized and characterized. Homo‐ and copolymerizations of methyl acrylate (MA) and 1‐hexene with bis(β‐ketoamino)copper(II) complexes activated with methylaluminoxane (MAO) were investigated in detail. MA was polymerized in high conversion (>72%) to produce the syndio‐rich atactic poly(methyl acrylate), but 1‐hexene was not polymerized with copper complexes/MAO. Copolymerizations of MA and 1‐hexene with 1 , 2 /MAO produced acrylate‐enriched copolymers (MA > 80%) with isolated hexenes in the backbone. The calculation of reactivity ratios showed that r(MA) is 8.47 and r(hexene) is near to 0 determined by a Fineman‐Ross method. The polymerization mechanism was discussed, and an insertion‐triggered radical mechanism was also proposed. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1113–1121, 2010     

Ni(II) and Pd(II) complexes bearing benzocyclohexane–ketoarylimine for copolymerization of norbornene with 5‐norbornene‐2‐carboxylic ester

A serial of late transition metal complexes, which bearing Benzocyclohexane–ketoarylimine ligand and named as Mt(benzocyclohexane–ketoarylimino)₂ {Mt(bchkai)₂: Mt=Ni or Pd; bchkai=C₁₀H₈(O)CN(Ar)CH₃; Ar=naphthyl or fluoryl}, have been synthesized and characterized. The molecular structures of the ligands and nickel complex have been confirmed by X‐ray single‐crystal analyses. The nickel complexes exhibited very high activity up to 2.7 × 10⁵ g_polymer/mol_Ni·h and palladium complexes showed high activity up to 2.3 × 10⁵ g_polymer/mol_Pd·h for norbornene (NB) homo‐polymerization with tris(pentafluorophenyl)borane as cocatalyst. The four complexes were effective for copolymerization of NB and 5‐norbornene‐2‐carboxylic acid methyl ester (NB‐COOCH₃) in relatively high activities (0.1–2.4 × 10⁵ g_polymer/mol_Mt·h) and produced the addition‐type copolymers with relatively high molecular weights (0.5 × 10⁵–1.2 × 10⁵ g/mol) as well as narrow molecular weight distributions (PDI < 2 for all polymers). Influences of the metals and comonomer feed content on the polymerization activity as well as on the incorporation rates (20.9–42.6%) were investigated. The achieved NB/NB‐COOCH₃ copolymers were confirmed to be noncrystalline, exhibited good thermal stability (T_d > 400°C) and showed good solubility in common organic solvents. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Radical copolymerization of acrylonitrile with 2,2,2‐trifluoroethyl acrylate for dielectric materials: Structure and characterization

Radical copolymerization based on acrylonitrile (AN) and 2,2,2‐Trifluoroethyl acrylate (ATRIF) initited by AIBN was investigated in acetonitrile solution. The resulting poly(AN‐co‐ATRIF) copolymers were characterized by ¹H, ¹³C, and ¹⁹F NMR and IR spectroscopy, and size exclusion chromatography (SEC). Their compositions were assessed by ¹H NMR. The kinetics of radical copolymerization of AN with ATRIF was investigated from sereval experiments achieved at 70 °C from initial [AN]₀/[ATRIF]₀ molar ratios ranging between 20/80 and 80/20 and was enabled to determine the reactivity ratios of both comonomers. From the monomer—polymer copolymerization curve, the Fineman–Ross and Kelen–Tüdos laws enabled to assess the reactivity ratios (r_AN= r₁ = 1.25 ± 0.04 and r_ATRIF = r₂ = 0.93 ± 0.05 at 70 °C) while the revised patterns scheme led to r₁₂ = r_AN = 1.03, and r₂₁ = r_ATRIF = 0.78 at 70 °C. In all cases, r_AN x r_ATRIF product was close to unity, which indicates that poly(AN‐co‐ATRIF) copolymers exhibit a random structure. This was also confirmed by the Igarashi's and Pyun's laws which revealed the presence of AN‐ATRIF, AN‐AN, and ATRIF‐ATRIF dyads. The Q and e values for ATRIF were also assessed (Q₂ = 0.62 and e₂ = 0.93). The glass transition temperature values, T_g, of these copolymers increased from 17 to 61 °C as the molar percentage of ATRIF decreased from 77 to 16% in the copolymer. Thermogravimetry analysis of poly(AN‐co‐ATRIF) copolymers showed a good thermal stability compared to that of poly(ATRIF) homopolymer due to incorporation of AN comonomer. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 3856–3866     

Facile synthesis of poly(hydroxyethyl acrylate) by frontal free‐radical polymerization

We report the first synthesis of poly(hydroxyethyl acrylate) (PHEA) without solvent by free‐radical frontal polymerization (FP) at ambient pressure. In a typical run, the appropriate amounts of reactant (hydroxyethyl acrylate) and initiator (1,1‐di(tert‐butylperoxy)‐3,3,5‐trimethylcyclohexane) (Luperox 231) were mixed together at ambient pressure. FP was initiated by heating the wall of the tube with a soldering iron, and the resultant hot fronts were allowed to self‐propagate throughout the reaction vessel. Once initiated, no further energy was required for polymerization to occur. To study the macrokinetics, we also produced PHEA frontally with ammonium persulfate as initiator and dimethyl sulfoxide as the solvent. The dependences of the front velocity and front temperature on the initiator concentration and reactant dilution were investigated. The front temperatures were between 124 and 157 °C, depending on the ammonium persulfate concentration. Thermogravimetric analysis indicates that PHEA prepared by FP with ammonium persulfate as initiator had higher thermal stability than solvent‐free frontally prepared PHEA with Luperox 231 as initiator. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 873–881, 2007     

Controlled synthesis of carboxylic acid end‐capped poly(heptadecafluorodecyl acrylate) and copolymers with 2‐hydroxyethyl acrylate

1H,1H,2H,2H‐Heptadecafluorodecyl acrylate (AC8) was polymerized by reversible addition–fragmentation chain transfer and copolymerized with 2‐hydroxyethyl acrylate with the formation of random and block copolymers, respectively. The kinetics of the (co)polymerization was monitored with ¹H NMR spectroscopy and showed that the homopolymerization and random copolymerization of AC8 were under control. As a result of this control and the use of S‐1‐dodecyl‐S‐(α,α′‐dimethyl‐α″‐acetic acid)trithiocarbonate as a chain‐transfer agent, the copolymer chains were end‐capped by an α‐carboxylic acid group. Moreover, the controlled polymerization of AC8 was confirmed by the successful synthesis of poly(1H,1H,2H,2H‐heptadecafluorodecyl acrylate)‐b‐poly(2‐hydroxyethyl acrylate) diblock copolymers, which were typically amphiphilic compounds. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1499–1506, 2007     

Kinetics of methyl methacrylate and n‐butyl acrylate copolymerization mediated by 2‐cyanoprop‐2‐yl dithiobenzoate as a RAFT agent

The RAFT (co)polymerization kinetics of methyl methacrylate (MMA) and n‐butyl acrylate (BA) mediated by 2‐cyanoprop‐2‐yl dithiobenzoate was studied with various RAFT concentrations and monomer compositions. The homopolymerization of MMA gave the highest rate. Increasing the BA fraction f_BA dramatically decreased the copolymerization rate. The rate reached the lowest point at f_MMA ～ 0.2. This observation is in sharp contrast to the conventional RAFT‐free copolymerization, where BA homopolymerization gave the highest rate and the copolymerization rate decreased monotonously with increasing f_MMA. This peculiar phenomenon can be explained by the RAFT retardation effect. The RAFT copolymerization rate can be described by 〈R_p〉/〈R_p〉₀ = (1 + 2(〈k_c〉/〈k_t〉)〈K〉)[RAFT]₀)^?0.5, where 〈R_p〉₀ is the RAFT‐free copolymerization rate and 〈K〉 is the apparent addition–fragmentation equilibrium coefficient. A theoretical expression of 〈K〉 based on a terminal model of addition and fragmentation reactions was derived and successfully applied to predict the RAFT copolymerization kinetics with the rate parameters obtained from the homopolymerization systems. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3098–3111, 2007     

Free‐radical copolymerization of styrene with butyl acrylate. II. Elemental kinetic copolymerization step predictions from homopolymerization data

The free‐radical copolymerization of styrene and butyl acrylate has been carried out in benzene at 50 °C. The lumped k _p/k parameter (where k _p and k _t are the average copolymerization propagation and termination rate constants, respectively) has been determined. Applying the implicit penultimate unit model for the overall copolymerization propagation rate coefficient and the terminal unit effect for the overall copolymerization termination rate coefficient and using the homopolymerization kinetic coefficients, we have found good qualitative agreement between the experimental and theoretical k _p/k values. The variation of the copolymerization rate in solution with respect to the values previously found in bulk has been ascribed to a chain length effect on the copolymerization termination rate coefficient. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 130–136, 2004     

Graft copolymerization of butyl acrylate and 2‐ethyl hexyl acrylate from labile chlorines of poly(vinyl chloride) by atom transfer radical polymerization

Trace amounts of labile chlorines present in poly(vinyl chloride) (PVC) were found to act as initiation sites for the preparation of graft copolymers of PVC by copper‐mediated atom transfer radical polymerization (ATRP). High grafting yields were attained during the graft copolymerizations of n‐butyl acrylate (161.8%) and 2‐ethyl hexyl acrylate (51.2%) in 7.5 h. In both cases, the grafting proceeded with first‐order kinetics with respect to the monomer concentrations, this being typical for ATRP. Gel permeation chromatography traces of the resulting products did not exhibit additional peaks attributable to the formation of free homopolymers. The presented procedure offers an efficient means of preparing self‐plasticized PVC structures. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3457–3462, 2003     

Copper catalyzed atom transfer radical copolymerization of glycidyl methacrylate and 2‐ethylhexyl acrylate

This investigation reports the atom transfer radical copolymerization (ATRcP) of glycidyl methacrylate (GMA) and 2‐ethylhexyl acrylate (EHA). Poly(glycidyl methacrylate) (PGMA) has easily transformable pendant oxirane group and poly(2‐ethylhexyl acrylate) (PEHA) has very low T_g. They are the important components of coating and adhesive materials. Copolymerization of GMA and EHA was carried out in bulk and in toluene at 70 °C at different molar feed ratios using CuCl as catalyst in combination with 2,2′‐bypyridine (bpy) as well as N,N,N′,N″,N″‐pentamethyl diethylenetriamine (PMDETA) as ligand. The molecular weight (M_n) and the polydispersity index (PDI) of the polymers were determined by GPC analysis. The molar composition of the copolymers was determined by ¹H NMR analysis. The reactivity ratios of GMA (r₁) and EHA (r₂) were determined using Finemann‐Ross and Kelen‐Tudos linearization methods and those had been compared with the literature values for conventional free radical copolymerization. The thermal properties of the copolymers were studied by DSC and TGA analysis. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 6526–6533, 2009     

Mn2(CO)10‐induced controlled/living radical copolymerization of vinyl acetate and methyl acrylate: Spontaneous formation of block copolymers consisting of gradient and homopolymer segments

The controlled/living radical polymerization of vinyl acetate (VAc) and its copolymerization with methyl acrylate (MA) were investigated in bulk or fluoroalcohols using manganese complex [Mn₂(CO)₁₀] in conjunction with an alkyl iodide (R? I) as an initiator under weak visible light. The manganese complex induced the controlled/living radical polymerization of VAc even in the fluoroalcohols without any loss of activity. The R? I/Mn₂(CO)₁₀ system was also effective for the copolymerization of MA and VAc, in which MA was consumed faster than VAc, and then the remaining VAc was continuously and quantitatively consumed after the complete consumption of MA. The ¹H and ¹³C NMR analyses revealed that the obtained products are block copolymers consisting of gradient MA/VAc segments, in which the VAc content gradually increases, and homopoly(VAc). The use of fluoroalcohols as solvents increased the copolymerization rate, controllability of the molecular weights, and copolymerizability of VAc. The saponification of the VAc units in poly(MA‐grad‐VAc)‐block‐poly(VAc) resulted in the corresponding poly(MA‐co‐γ‐lactone)‐block‐poly(vinyl alcohol) due to the intramolecular cyclization between the hydroxyl and neighboring carboxyl groups in the gradient segments. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1343–1353, 2009     

Copolymerization of norbornene and 5‐norbornene‐2‐yl acetate using novel bis(β‐ketonaphthylamino)Ni(II)/B(C6F5)3/AlEt3 catalytic system

Vinyl‐type copolymerization of norbornene (NBE) and 5‐NBE‐2‐yl‐acetate (NBE‐OCOMe) in toluene were investigated using a novel homogeneous catalyst system based on bis(β‐ketonaphthylamino)Ni(II)/B(C₆F₅)₃/AlEt₃. The copolymerization behavior as well as the copolymerization conditions, such as the levels of B(C₆F₅)₃ and AlEt₃, temperature, and monomer feed ratios, which influence on the copolymerization were examined. Without combination of AlEt₃, the catalytic bis(β‐ketonaphthylamino)Ni(II)/B(C₆F₅)₃ exhibited very high catalyst activity for polymerization of NBE. Combination of AlEt₃ in catalyst system resulted in low conversion for polymerization of NBE. For copolymerization of NBE and NBE‐OCOMe, involvement of AlEt₃ in catalyst is necessary. Slight addition of NBE‐OCOMe in copolymerization of NBE and NBE‐OCOMe gives rise to significant increase of catalyst activity for catalytic system bis(β‐ketonaphthylamino)Ni(II)/B(C₆F₅)₃/AlEt₃. Nevertheless, excess increase of the NBE‐OCOMe content in the comonomer feed ratios results in decrease of conversion as well as activity of catalyst. The achieved copolymers were confirmed to be vinyl‐addition copolymers through the analysis of FTIR, ¹H NMR, and ¹³C NMR spectra. ¹³C NMR studies further revealed the composition of the copolymer and the incorporation rate was 7.6–54.1 mol % ester units at a content of 30–90 mol % of the NBE‐OCOMe in the monomer feeds ratios. TGA analysis results showed that the copolymer exhibited good thermal stability (T_d > 410 °C) and failed to observe the glass transitions temperature over 300 °C. The copolymers are confirmed to be noncrystalline by WAXD analysis results and show good solubility in common organic solvents. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3990–4000, 2009     

Radical Ring‐Opening Polymerization Behavior of 1,1‐Dicyano‐2‐Vinylcyclopropane and Its Copolymerization with 1‐Cyano‐1‐Ester‐2‐Vinylcyclopropane

Radical ring‐opening polymerization of 1,1‐dicyano‐2‐vinylcyclopropane 1 was performed in benzonitrile to find the corresponding homopolymer 2 soluble in organic solvents was successfully obtained while that in other solvents gave crosslinked and thus insoluble homopolymer. In addition, 1 underwent radical copolymerization with 1‐cyano‐1‐ester‐2‐vinylcyclopropanes 3 and 4 to afford the corresponding copolymers 7 and 8 . By increasing the content of the 1 ‐derived unit in the resulting copolymers, the solubility of the copolymers in organic solvents became lower and the residual weights at 600 °C and their glass transition temperatures became higher. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1723–1729     

New initiator system for the anionic polymerization of (meth)acrylates in toluene. IV. Random copolymerization of (meth)acrylates in toluene initiated by s-BuLi ligated by lithium silanolates

Copolymerization of binary mixtures of alkyl (meth)acrylates has been initiated in toluene by a mixed complex of lithium silanolate  (s-BuMe₂SiOLi) and s-BuLi (molar ratio > 21) formed in situ by reaction of s-BuLi with hexamethylcyclotrisiloxane (D₃). Fully acrylate and methacrylate copolymers, i.e., poly(methyl acrylate-co-n-butyl acrylate), poly(methyl methacrylate-co-ethyl methacrylate), poly(methyl methacrylate-co-n-butyl methacrylate), poly(methyl methacrylate-co-n-butyl methacrylate), poly(isobornyl methacrylate-co-n-butyl methacrylate), poly(isobornyl methacrylate-co-n-butyl methacrylate) of a rather narrow molecular weight distribution have been synthesized. However, copolymerization of alkyl acrylate and methyl methacrylate pairs has completely failed, leading to the selective formation of homopoly(acrylate). As result of the isotactic stereoregulation of the alkyl methacrylate polymerization by the s-BuLi/s-BuMe₂SiOLi initiator, highly isotactic random and block copolymers of (alkyl) methacrylates have been prepared and their thermal behavior analyzed. The structure of isotactic poly(ethyl methacrylate-co-methyl methacrylate) copolymers has been analyzed in more detail by Nuclear Magnetic Resonance (NMR). © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 2525–2535, 1999     

Functionalization of vinylic addition polynorbornenes via efficient copolymerization of norbornene using Ni(II)‐Me complexes

The facile and efficient functionalization of polynorbornene has been achieved through direct copolymerization of norbornene (NB) with 5‐norbornene‐2‐yl acetate (NBA) or 5‐norbornene‐2‐methanol (NBM) using a series of β‐ketiminato Ni(II)‐Me pyridine complexes 1–4 (Scheme 2 ) in the presence of B(C₆F₅)₃. Remarkably, the monomer conversion could reach up to about 96% in 10 min in the NB/NBA copolymerization. The copolymers with wide NBA contents (3.3–38.4 mol %) were obtained by variation of reaction conditions. These copolymers have high molecular weights (MWs) (M_n = 41.8–144 kg/mol) and narrow MW distributions (M_w/M_n = 1.80–2.27). In the absence of alkyl aluminum compounds, a monomer conversion of 81% was observed in the NB/NBM copolymerization, and copolymers with NBM content in the range of 11.2–21.8 mol % were obtained by variation of reaction conditions. In addition, Ni(II)‐Me pyridine complexes 2 was very active at a low B/Ni molar ratio of 6, while bis‐ligand complex 6 bearing the same ligand just showed moderate efficiency at a high B/Ni molar ratio of 20. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Radical ring‐opening copolymerization behavior of vinyloxirane: Synthesis of copolymer from 2‐isopropenyl‐3‐phenyloxirane and styrene and its functionalization

The radical ring‐opening copolymerization of 2‐isopropenyl‐3‐phenyloxirane (1) with styrene (St) was examined to obtain the copolymer [copoly(1‐St)] with a vinyl ether moiety in the main chain. The copolymers were obtained in moderate yields by copolymerization in various feed ratios of 1 and St over 120 °C; the number‐average molecular weights (M_n) were estimated to be 1800–4200 by gel permeation chromatography analysis. The ratio of the vinyl ether and St units of copoly(1‐St) was estimated with the ¹H NMR spectra and varied from 1/7 to 1/14 according to the initial feed ratio of 1 and St. The haloalkoxylation of copoly(1‐St) with ethylene glycol in the presence of N‐chlorosuccinimide produced a new copolymer with alcohol groups and chlorine atoms in the side group in a high yield. The M_n value of the haloalkoxylated polymer was almost the same as that of the starting copoly(1‐St). The incorporated halogen was determined by elemental analysis. The analytical result indicated that over 88% of the vinyl ether groups participated in the haloalkoxylation. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 3729–3735, 2000     

Homo‐ and copolymerization of norbornene and 5‐norbornene‐2‐yl acetate with bis‐(β‐ketonaphthylamino)palladium(II)/B(C6F5)3 catalytic system

The polymerization of norbornene with bis(β‐ketonaphthylamino) palladium(II), Pd{CH₃C(O)CHC[N(naphthyl)]CH₃}₂, in combination with tris(pentafluorophenyl)borane (B(C₆F₅)₃), was investigated by varying the B:Pd(II) molar ratio, monomer concentration, reaction temperature, and time. The catalytic activity was found to reach 2.8 × 10⁴ gPolymer/(molPd^?h) and the obtained polynorbornene (PNBE) was confirmed to be vinyl addition polymer and showed good thermo‐stability (T_dec > 350°C), but exhibited poor solubility in organic solvents due to the relative higher stereo regularity. Pd{CH₃C(O)CHC[N(naphthyl)]CH₃}₂/B(C₆F₅)₃ system is also an active catalyst for copolymerization of norbornene and 5‐norbornene‐2‐yl acetate (NBE‐OCOCH₃) in toluene with moderate yields (in 9.2–36.5% yields) and produces the addition‐type copolymer with relatively high molecular weights (0.96 × 10⁴–2.13 × 10⁴ g/mol). The incorporation of functional group in the copolymer can be controlled up to 0.9–23.5 mol% by varying the NBE‐OCOCH₃ monomer feed ratios from 10 to 90%. The copolymers are proved to be noncrystalline and show good solubility in common organic solvents and excellent thermal stability up to 350°C. Copyright © 2011 John Wiley & Sons, Ltd.