Free Radical Copolymerization of Novel Methacrylates with Acrylonitrile and Determination of Monomer Reactivity Ratios

p-methoxyphenoxy and p-chlorophenoxy group containing methacrylate based monomer 2-(p-methoxyphenoxy)-2-oxo-ethyl methacrylate (pMPOEMA) and 2-(p-chlorophenoxy)-2-oxo-ethyl methacrylate (p-ClPOEMA) were synthesized by reacting p-methoxyphenyl chloroacetate (pMPClAcO) and p-chlorophenyl chloroacetate (pClPClAcO) with sodium methacrylate in acetonitrile respectively. (pMPClAcO) and (pClPClAcO) were prepared by reacting p-methoxyphenol and p-chlorophenol dissolved in benzene with chloroacetylchloride. The free-radical-initiated copolymerization of (pMPOEMA) and (pClPOEMA) with acrylonitrile (AN) 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 analysis of reactivity ratios revealed that pMPOEMA and pClPOEMA are more reactive than AN, and copolymers formed are statistically in nature. The molecular weights ( and ) and polydispersity index of the polymers were determined using gel permation chromagtography. Thermogravimetric analysis of the polymers reveal that the thermal stability of the copolymers increases with an increase in the mole fraction of AN in the copolymers. Glass transition temperatures of the copolymers were found to decrease with an increase in the mole fraction of AN in the copolymers.     

Copolymerization of 2-(4-tert-butylphenoxy)-2-oxo-ethyl Methacrylate with Methyl Methacrylate and Styrene: Synthesis, Characterization, and Monomer Reactivity Ratios

A tertierbutylphenoxy group containing methacrylate based monomer 2-(4-tert-butylphenoxy)-2-oxo-ethyl methacrylate (TBPOEMA) was synthesized by reacting 4-tertierbutylphenyl chloroacetate (TBPClAcO) with sodium methacrylate in acetonitrile. TBPClAcO was prepared by reacting tertierbutylphenol dissolved in benzene with chloroacetylchloride. The free-radical-initiated copolymerization of TBPOEMA, with methyl methacrylate (MMA) and styrene (ST) was carried out in dimethylsulphoxide (DMSO) solution at 65°C using 2,2-azobisisobutyronitrile (AIBN) as an initiator with different monomer-to-monomer ratios in the feed. The monomer TBPOEMA and copolymers were characterized by FTIR, ¹H- and ¹³C-NMR spectral studies. The copolymer composition obtained from the ¹H-NMR spectra led to the determination of reactivity ratios. The reactivity ratios of the monomers were determined by the application of Finemann–Ross and Kelen–Tüdös linear methods and the Behnken nonlinear least-squares method. The analysis of reactivity ratios revealed that MMA and ST are more reactive than TBPOEMA, and copolymers formed are statistical in nature. The molecular weights _w and _n) and polydispersity index of the polymers were determined using gel permation chromagtography. Thermogravimetric analysis of the polymers reveal that the thermal stability of the copolymers increases with an increase in the mole fraction of TBPOEMA in the copolymers. Glass transition temperatures of the copolymers were found to decrease with an increase in the mole fraction of TBPOEMA in the copolymers. The apparent thermal decomposition activation energies (E _d) were calculated by Ozawa method using the SETARAM Labsys TGA thermobalance.     

Copolymerizations of 2-(dimethylamino)ethyl methacrylate with (methyl)acrylates initiated by a neutral Pd(II)-based complex

The copolymerization reactions of 2-(dimethylamino)ethyl methacrylate (DMAEMA) with methyl methacrylate (MMA), butyl methacrylate (n-BMA), methyl acrylate (MA), and butyl acrylate (n-BA), respectively, by an environmentally stable palladium acetylide Pd(PPh₃)₂(CCPh)₂ (PPP) have been investigated. PPP shows relatively high catalytic activity for these copolymerizations. Reactivity ratios of these copolymerizatins have been measured and calculated by the Kelen-Tüdös method for the first time, and their values are as follows: (1) r_DMAEMA=1.13, r_MMA=1.07; (2) r_DMAEMA=0.77, r_n-BMA=0.84; (3) r_DMAEMA=1.54, r_MA=0.09; (4) r_DMAEMA=0.71, r_n-BA=0.14. The mechanism of these copolymerizations was discussed and a radical mechanism was proposed.     

Free Radical Copolymerization of Methyl Methacrylate and Styrene with N-(4-Carboxyphenyl)maleimide

The free radical copolymerization of methyl methacrylate (MMA) or styrene (St) with N-(4-carboxyphenyl)maleimide (CPMI) was carried with AIBN as an initiator in THF solvent at 80°C. A series of copolymers of MMA and St with CPMI were prepared using different feed ratios of comonomers. The values of monomer reactivity ratios (r₁, r₂) determined by Fineman-Ross and Kelen-Tudos methods are 0.26 and 2.51 in the CPMI/MMA system and 0.08 and 0.22 in the CPMI/St system. Alfrey–Price Q-e values for CPMI were calculated as Q = 1.05 and e = 0.41 in the CPMI/MMA system and Q = 1.21 and e = 0.91 in the CPMI/St system. The polymer samples have been characterized by solubility tests, intrinsic viscosity measurements, FT-IR and ¹H-NMR spectral analysis, and thermo-gravimetric analysis. It was found that the initial and final decomposition temperatures increased with increasing the amount of CPMI in the copolymer. The integral procedural decomposition temperature and energy of activation of thermal degradation have also been reported.     

Glass transition temperature of methyl methacrylate–ethyl α‐benzoyloxymethylacrylate copolymers

Poly(ethyl α‐benzoyloxymethylacrylate) (EBMA) and copolymers of methyl methacrylate (MMA) with EBMA have been prepared by free radical polymerization. Monomer precursors of ethyl α‐benzoyloxymethylacrylate have likewise been polymerized. Glass transition temperatures (T_g) of homo and copolymers have been determined by differential scanning calorimetry. The Johnston equation, which considers the influence of monomeric unit distribution on the copolymer glass transition temperature, has been used to explain the T_g behaviour. T_g12 has been calculated by the application of the Johnston equation, which gave a value markedly lower than the average value expected from the additive contribution of the T_g of the corresponding homopolymers. © 2000 Society of Chemical Industry     

Polyesters based on two silarylene or germarylene moieties: Synthesis under phase‐transfer conditions

Polyesters (PEs) containing two heteroatoms (Si and/or Ge) in the main chain, derived from the acid dichlorides bis(4‐chloroformylphenyl) ethylmethylsilane, bis(4‐chloroformylphenyl) diethylsilane, bis(4‐chloroformylphenyl) diethylgermane, and bis(4‐chloroformylphenyl) di‐ⁿbutylgermane and from the diphenols bis(4‐hydroxyphenyl) ethylmethylsilane, bis(4‐hydroxyphenyl) diethylsilane, bis(4‐hydroxyphenyl) diethylgermane, and bis(4‐hydroxyphenyl) di‐ⁿbutylgermane, were synthesized under phase‐transfer conditions with three quaternary ammonium salts as phase‐transfer catalysts and three NaOH concentrations in the aqueous phase. PEs were characterized with IR and NMR spectroscopy, including ²⁹Si‐NMR. In general, the yields and intrinsic viscosities were low, and in some cases, an increase in these parameters was shown as a result of the catalyst effect. An increase in the NaOH concentration caused a decrease in the yields because of a hydrolytic process. PEs with Si were thermally more stable than those with Ge. The glass‐transition temperatures decreased when the side chains bonded to the heteroatoms were longer. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Copolymerizations involving N-vinyl-2-pyrrolidone

Low conversion copolymerizations have been conducted with N-vinyl-pyrrolidone (VP) as monomer-1 and the following reagents were used as monomer-2: acryloxymethylpentamethyldisiloxane (AMS), methacryloxymethylpentamethyl disiloxane (MMS), n-butyl acrylate (BA) and 2-hydroxyethylmethacrylate (HEMA). In the same order the derived monomer reactivity ratios (r₁, r₂) were (0.34, 1.57); (0.04, 4.92); (0.02, 0.80) and (0.05, 3.12). For a range of different feed compositions within each system integral curves were thereby computed for the instantaneous copolymer composition throughout all stages of conversion. These gave predictions on compositional heterogeneity which compared satisfactorily with the clear, translucent or opaque appearance of copolymers prepared to very high conversion via γ-irradiation. However, the VP-HEMA system, for which there is no azeotropic composition, yielded optically clear copolymers at all feed compositions. This finding is explained on the basis of the almost iso-refractive nature of the two homopolymers and/or strong thermodynamic compatibility among copolymers and homopolymers as evidenced by a single T_g observed on cast films.