Copolymerization of N-vinylsuccinimide with butyl acrylate in an electron-donor medium of tertiary aminese

The effect of electron-donor solvents on the parameters of the NMR signals of vinyl protons in N-vinylsuccinimide and butyl acrylate was examined. The kinetics of copolymerization of N-vinylsuccinimide with butyl acrylate in triethylamine and tributylamine was studied by monitoring the running concentrations of the monomers in the course of the reaction. The copolymerization constants were calculated. The diad and triad composition of the copolymers formed in the medium of tertiary amines was predicted, and their microstructural nonuniformity was evaluated.     

Synthesis and characterization of poly(phenylacetylenes) featuring activated ester side groups

Four monomers based on 4‐ethynylbenzoic acid have been synthesized, one of those featuring an activated ester. With the metathesis catalytic system WCl₆/Ph₄Sn, these acetylenic monomers could successfully be polymerized yielding conjugated polymers with molecular weights of around 10,000 to 15,000 g/mol and molecular weight distributions M_w/M_n ≤ 2.1. Also the copolymerization of phenylacetylene or methyl 4‐ethynylbenzoate with pentafluorophenyl 4‐ethynylbenzoate as reactive unit was conducted. Polymer analogous reactions of the reactive polymers and copolymers with amines have been investigated and it was found that poly(pentafluorophenyl 4‐ethynylbenzoate) featured a significant reactivity, such that reactions proceeded quantitatively even with aromatic amines. Moreover the UV‐Vis spectra of the activated ester based polymer before and after conversion with aliphatic amines showed a change, indicating an effect on the conjugated backbone of the polymers. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010     

Synthesis and polymerizations of methyl 3,3-difluorocyclobutene-1-carboxylate and methyl 3,3,4,4-tetrafluorocyclobutene-1-carboxylate

Two new monomers, methyl 3,3-difluorocyclobutene-1-carboxylate (MDFC) and methyl 3,3,4,4-tetrafluorocyclobutene-1-carboxylate (MTFC), were synthesized. Under free radical conditions, MDFC gave homopolymer; MTFC did not. Copolymerizations of these monomers showed them to behave as very electron-deficient monomers, MTFC more so than MDFC. MDFC copolymerized with various vinyl ethers and styrenes to give high yields of almost 1:1 copolymers. Acrylonitrile copolymerized in lower yield with less incorporation of MDFC; trimethylethylenetricarboxylate did not copolymerize. Bicyclobutane-1-carbonitrile copolymerized well. MTFC copolymerized with the very electron-rich monomers t-butyl vinyl ether and p-methoxystyrene, leading to alternating and nearly alternating copolymers, respectively, and even styrene tended to give almost 1:1 copolymers. Acrylonitrile gave only polyacrylonitrile, and trimethylethylenetricarboxylate did not react with MTFC under free radical conditions. The reaction of MTFC with the electron-rich monomers t-butyl vinyl ether and p-methoxystyrene occurred spontaneously via charge transfer complexes. Thermally, the copolymers were rather stable, those of MTFC more so than those of MDFC.     

Synthesis and characterization of poly(p-arylene sulfide ketone/Schiff base) copolymers

Poly(p-arylene sulfide ketone/Schiff base) copolymers(PASK/SB) were prepared by solution polycondensation of 4,4’-diflurobenzophenone(DFBP) and N-phenyl(4,4’-diflurodiphenyl) ketimine(DFBI) with sodium sulfide in the presence of sodium hydroxide under normal pressure.Elemental analyses,FT-IR,NMR,DSC,TGA and XRD were used to characterize the resultant copolymers.It was found that the copolymers had good thermal properties with glass transition temperature(T_g) of 155.0-172.0°C,melting temperature(T_m) of 298-344°C,5%weight loss temperatures(T_d) of 471.0-501.5°C.These copolymers were almost amorphous with the content of DFBI beyond 30%.The polymer with 100% DFBI had excellent solubility,and it could dissolve in some solvents such as tetrahydrofuran(THF) and N-methyl-2- pyrrolidone(NMP).The processability of polymers was improved.Meantime the viscosity of PASK made from hydrolysis of PASK/SB(H-PASK/SB) was greatly improved from 0.135 dL/g to 0.605 dL/g.     

Glass-transition temperature of polydialkyl fumarate copolymers

Two dialkyl fumarate monomers were copolymerized with styrene and methyl methacrylate. The reactivity ratios of the monomers were calculated, and the glass transition temperature-composition diagrams for the copolymers were measured. The experimental T_g data of the copolymers were fitted to several empirical equations proposed in the literature. A comparison is made between the copolymers and the blends of the corresponding polymers. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1839–1845, 1999     

Simple and effective one‐pot synthesis of (meth)acrylic block copolymers through atom transfer radical polymerization

The synthesis of di‐ and triblock copolymers using atom transfer radical polymerization (ATRP) of n‐butyl acrylate (BA) and methyl methacrylate (MMA) is reported. In particular, synthetic procedures that allow for an easy and convenient synthesis of such block copolymers were developed by using CuBr and CuCl salts complexed with linear amines. Polymerizations were successfully conducted where the monomers were added to the reactor in a sequential manner. Poor cross‐propagation between poly(n‐butyl acrylate) (PBA) macroinitiators and MMA was minimized, and therefore control of molecular weights and distributions was realized, by using halogen exchange—a technique involving the addition of CuCl to the MMA during the chain extension of the PBA macroinitiator. High molecular weight (M_n ∼ 90,000) and low polydispersity (M_w /M_n < 1.35) ABA triblock copolymers were also prepared and their structure and properties in bulk have been preliminary characterized indicating the potential of ATRP for the production of all‐acrylic thermoplastic elastomers. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2023–2031, 2000     

Polymerization behavior of bistrimethylsilyloxycycloalkenes

The radical copolymerizations of bistrimethylsilyloxycycloalkenes, such as 1,2-bistrimethylsilyloxycyclobutene (I), 1,2-bistrimethylsilyloxycyclopentene (II), and 1,2-bistrimethylsilyloxycyclohexene (III), were carried out with acceptor monomers, such as maleic anhydride, N-phenylmaleimide, and methyl methacrylate. I and II gave alternating copolymers with maleic anhydride and random copolymers with N-phenylmaleimide but no copolymer with methyl methacrylate. III gave no copolymer with the acceptor monomers. These polymerization behaviors of bistrimethylsilyloxycycloalkenes were explained primarily in terms of the electron donor–acceptor interaction between both monomers.     

Mechanistic and Synthetic Aspects of Atom Transfer Radical Polymerization

Abstract

Mechanistic and synthetic aspects of atom transfer radical polymerization (ATRP) are reviewed. This controlled/“living” system polymerizes many monomers including styrenes, (meth)acrylates, acrylonitrile and dienes. The halogen end groups can be converted to other functional groups such as amines and azides. In addition to producing well-defined linear homopolymers, statistical copolymers, block copolymers, and gradient copolymers, ATRP can be used to synthesize graft and hyperbranched copolymers through copolymerization with functionalized monomers. Selection of appropriate conditions for ATRP depends on targeted molecular weight and degree of polymer chain end-functionality and includes considering the monomer(s) to be polymerized, initiator structure/reactivity, amount of catalyst/deactivator used, halogen end-group used, and temperature.     

Synthesis and characterization of styrenic polymers with pendant pyrazole groups. II

The synthesis of styrenic monomers that have pyrazolic or bipyrazolic pendant groups is described. Their homopolymerization and their copolymerization with maleic anhydride (MA) and N-(3-acetoxy propyl) maleimide is reported. The monomers were prepared from the Williamson reaction between 2-pyridine carbinol, hydroxy monopyrazole, hydroxy bipyrazole, and chloromethyl styrene. The homopolymerizations of such styrenic monomers were tried under different conditions, which led to low molecular weight polymers with a high polydispersity. However, alternating copolymers were obtained using maleic anhydride or N-(3-acetoxy propyl) maleimide as comonomers, as shown by ¹H-NMR, elemental analysis, and reactivity ratios r₁ and r₂. Furthermore, the hydrolysis of the acetate function of different copolymers was performed quantitatively. Unlike the acetoxy copolymers, such products do not have any glass transition temperature. Thermogravimetric investigations have shown that these copolymers exhibit good thermostability. © 1994 John Wiley & Sons, Inc.     

Synthesis and Biological Activity of Acrylate Copolymers Containing 3-Oxo-N-allyl-1,2-benzisothiazole-3(2H)-carboxamide Monomer as a Marine Antifouling Coating

A type of grafted acrylate copolymer resins, containing 3-oxo-N-allyl-1,2-benzisothiazole-2(3H)-carboxamide monomer and heterocyclic monomers, was synthesized through the copolymeri- zation of methyl methacrylate (MMA) and butyl acrylate (BA) with functional monomers. The structures of the monomers and copolymers were validated by infrared (IR) and ¹H nuclear magnetic resonance (NMR) spectroscopies. The inhibitory activities of the copolymers on algae, bacteria, and barnacle larvae were measured, and the antifouling potencies against marine macrofouling organisms were investigated. The results showed that the grafted resin had significant inhibitory effects on the growth of three marine algae (Isochrysis galbana, Nannochloropsisoculata, and Chlorella pyrenoidosa), and three bacteria (Vibrio coralliilyticus, Staphylococcus aureus,and Vibrio parahaemolyticus). The target copolymers also showed excellent inhibition of the survival of barnacle larvae. Additionally, the release rate of the antifoulant and the results of the marine field tests indicated that the grafted copolymers had outstanding antifouling potency against the attachment of marine macrofouling organisms.     

Complexed copolymerization of vinyl compounds with alkylaluminum halides

The monomer reactivity in the complexed copolymerization of vinyl compounds with alkylaluminum halides has been extensively surveyed. Equimolar copolymers were obtained in various combinations of monomers which are classified into two monomer groups, A and B. The group B monomers are conjugated vinyl compounds having nitrile or carbonyl groups in the conjugated position and form complexes with alkylaluminum halides. The group A monomers are donor monomers having low values, such as olefins, haloolefins, dienes, and unsaturated esters. These A monomers belong to the same group of monomers which give alternating copolymers in conventional radical copolymerization with maleic anhydride, SO₂, and so on. In addition the complexed copolymerization has the same specific characteristics as the conventional alternating copolymerization, i.e., high reactivities of allyl-resonance monomers and inner olefins and no transfer of halogen atom to the copolymers in CCl₄. These features suggest little or no participation of the A monomer radical. The Q-e scheme is also discussed in terms of the monomer reactivity. More than two monomers selected from groups A and B give multicomponent copolymers in which alternating sequential structures hold with respect to A and B. Anomalous mutual reactivities between two B monomers in the terpolymerization were observed and indicate that the nature of radical in the complexed copolymerization may be different from that expected by the Lewis-Mayo equation. The complexed radical mechanism previously proposed is discussed in connection with the specific behavior mentioned above.     

Effect of monomer functional groups on the composition of some three component random phenolic copolymers

Some three-component random phenolic copolymers were prepared from three typical phenolic monomers; for example, p-chlorophenol, p-aminophenol, and p-cresol. Several samples of the copolymer were prepared by changing the feed composition and the composition of the copolymers was established by estimating ? NH₂ and ? OH groups by electrometric titration techniques in nonaqueous media. Halogen was estimated by Volhard's method. The average degree of polymerization (DP) of the copolymers was calculated from the features of the electrometric titration curves, and the effects of monomer functional groups on the composition of the copolymers were interpreted in terms of the electron-donating and electron-attracting nature of the substituents present in the monomers.     

Quinone copolymerization. I. Reactions of p-chloranil,p-benzoquinone,and 2,5-dimethyl-p-benzoquinone with vinyl monomers under free-radical initiation

The free-radical copolymerization reactions of p-chloranil, p-benzoquinone, and 2,5-di-methyl-p-benzoquinone with vinyl monomers were studied. Reactions of p-chloranil with styrene yielded copolymers of approximately 1:1 composition under a variety of reaction conditions. A copolymer containing a block of 1:1 of styrene:p-chloranil and a block of polystyrene was prepared. Several styrene-like monomers copolymerized with p-chloranil to yield copolymrs possessing considerable amounts of incorporated quinone. p-Benzoquinone copolymerized with 1,3-butadiene and 2-vinyl-pyridine to yield copolymers of significant molecular weights. Reactions of 2,5-dimethyl-p-benzoquinone with vinyl monomers did not yield any isolable polymeric products.     

Radical copolymerization of optically active l-menthyl vinyl ether with maleic anhydride,dimethyl maleate,and dimethyl fumarate

The copolymerizations of l-menthyl vinyl ether (l-MVE) with the monomers, that is, maleic anhydride (MAn), dimethyl maleate (DMM), and dimethyl fumarate (DMFu), were undertaken to obtain optically active copolymers. The optically active l-menthyl group in the side chain of copolymers was removed by the ether cleavage reaction with dry-hydrogen bromide gas. The ethercloven copolymers were still optically active. Hence it was concluded that asymmetric carbon atoms were introduced into the copolymer main chain, the reason given being that l-MVE and comonomers (MAn, DMM, and DMFu) made the stereoselective charge-transfer complex one another and copolymerized stereospecifically. From the results of the measurements of optical rotatory dispersion (ORD) and circular dichroism (CD) for copolymers before and after the ether cleavage reaction, the mode of bond opening for α,β-substituted monomers (MAn, DMM, and DMFu) was discussed and the microstructures of copolymers were prepared.     

Synthesis of linear block copolymers from methacrylic monomers using 4,6-di-tert-butyl-N-2,6-diisopropylphenyl)-o-iminobenzoquinone

Polymers based on methacrylic monomers were synthesized using 4,6-di-tert-butyl-N-(2,6-diisopropylphenyl)-o-iminobenzoquinone. They can be used for the directed synthesis of linear block copolymers with various compositions in the wide range of molecular weights under conditions of the polymerization according to the mechanism of reversible inhibition. It has been demonstrated that a structure of monomer plays the key role in the synthesis of block copolymers with relatively low values of the polydispersity coefficient. The optimal conditions for the synthesis of linear block copolymers based on methacrylic structures monomers have been revealed.

     

Synthesis and Characterization of Novel Methacrylate Monomers Having Pendant Oxime Esters and Their Copolymerization with Styrene

New methacrylate monomers, 2‐{[(diphenylmethylene)amino]oxy}‐2‐oxoethyl methacrylate (DPOMA) and 2‐{[(1‐phenylethylidene)ami no]oxy}‐2‐oxoethyl methacrylate (MMOMA) were prepared by reaction of sodium methacrylate with diphenylmethanone O‐(2‐chloroacetyl) oxime and 1‐phenylethanone O‐(2‐chloroacetyl) oxime, respectively. They were obtained from a reaction of chloroacetyl chloride with benzophenone oxime or acetophenone oxime. The free‐radical‐initiated copolymerization of (DPOMA) and (MMOMA) with styrene (St) were carried out in 1,4‐dioxane solution at 65°C using 2,2‐azobisisobutyronitrile (AIBN) as an initiator with different monomer‐to‐monomer ratios in the feed. The monomers and copolymers were characterized by FTIR, ¹H‐ and ¹³C‐NMR spectral studies. The copolymer compositions were evaluated by nitrogen content in polymers. The reactivity ratios of the monomers were determined by the application of Fineman–Ross and Kelen–Tüdös methods. The molecular weights (M¯_w and M¯_n) and polydispersity index of the polymers were determined by using gel permeation chromatography. Thermogravimetric analysis of the polymers reveals that the thermal stability of the copolymers increases with an increase in the mole fraction of St in the copolymers. The activation energies of the thermal degradation of the polymers were calculated with the MHRK method. Glass transition temperatures of the copolymers were found to decrease with an increase in the mole fraction of DPOMA or MMOMA in the copolymers. The antibacterial and antifungal effects of the monomers and polymers were also investigated on various bacteria and fungi. The photochemical properties of the polymers were investigated by UV and FTIR spectra.     

Janus Effect of Lewis Acid Enables One-Step Block Copolymerization of Ethylene Oxide and N-Sulfonyl Aziridine

One-step sequence-selective block copolymerization requires stringent catalytic control of monomers relative activity and enchainment order. It has been especially rare for A_nB_m-type block copolymers from simple binary monomer mixtures. Here, ethylene oxide (EO) and N-sulfonyl aziridine (Az) compose a valid pair provided with a bicomponent metal-free catalyst. Optimal Lewis acid/base ratio allows the two monomers to strictly block-copolymerize in a reverse order (EO-first) as compared with the conventional anionic route (Az-first). Livingness of the copolymerization facilitates one-pot synthesis of multiblock copolymers by addition of mixed monomers in batches. Calculation results reveal that a Janus effect of Lewis acid on the two monomers is key to enlarge the activity difference and reverse the enchainment order.     

Synthesis and free radical polymerization of 2-methylene-7-oxabicyclo[2.2.1]heptane

A new monomer, 2-methylene-7-oxabicyclo[2.2.1]heptane ( IV ) was synthesized via four steps. Its structure was confirmed by IR, ¹H-NMR, and ¹³C-NMR spectra as well as elementary analysis. Free radical polymerization and copolymerization of IV were investigated. No homopolymer was obtained due to the effect of allyl inhibition. When IV copolymerized with electron-donor monomers, such as vinyl acetate and stvrene, IV acted as inhibitor for the polymerization of vinyl acetate, but could not inhibit the polymerization of styrene. However, the copolymers of IV with electron-accepting monomers, such as methyl methacrylate, acrylonitrile, or maleic anhydride (MA) were obtained. The contents of IV in the copolymers increased as e values of electron-accepting monomers increased. Strictly alternating copolymer was obtained only in the case of MA and IV . The thermal properties of copolymers were investigated. © 1995 John Wiley & Sons, Inc.     

Chemical release control—Schiff bases of perfume aldehydes and aminostyrenes

Schiff bases of p- and m-aminostyrenes with perfume aldehydes such as citral, cinnamaldehyde, piperonal, vanillin, and ethyl vanillin were synthesized in ethanol in more than 50% yield. Water-soluble copolymers of these Schiff bases with N-vinyl-2-pyrrolidone or with N,N-dimethylacrylamide were obtained. The hydrolytic behavior of Schiff base monomers and copolymers to liberate perfume aldehydes was structure dependent, thereby affording chemical release control.     

Phenylquinoxaline–Aryl ester block copolymers

Phenylquinoxaline–aryl ester block copolymers were synthesized using well-defined phenolic hydroxyl terminated oligomers via a monomers/oligomer approach. Phenylquinoxaline oligomers with molecular weights of 5600 and 12,900 g/mol were prepared from the condensation of 1,4-bis(phenylglyoxalyl)benzene and 3,3′-diaminobenzidine in the presence of 4-hydroxylbenzil. The oligomers were copolymerized with isophthaloyl chloride and bisphenol A in tetrachloroethane to afford the desired phenylquinoxaline–aryl ester block copolymers. Copolymers with polyester compositions ranging from 15–50 wt % were prepared by controlling the monomers/oligomer stoichiometry. The majority of the materials displayed single phase morphologies with T_gs intermediate to the T_gs for the poly (phenylquinoxaline) and polyester homopolymers. Plots of the reciprocal of the T_g of the copolymers versus composition agreed well with values predicted by the Fox equation. A multiphase morphology was obtained for the copolymer with the highest polyester block length (? 13,000 g/mol), which displayed a T_g at 190 and 300°C indicative of a glassy–glassy system. Significant improvement in the elongations were observed for the copolymers relative to the poly(phenylquinoxaline) homopolymer. The improved elongations were obtained with minimal sacrifice to the modulus. These materials represent the first example of poly(phenylquinoxaline) block copolymers from well-defined phenylquinoxaline oligomers.