Monomer apparent reactivity ratios for acrylonitrile/ammonium itaconate radical copolymerization systems

Ammonium itaconate was first used to copolymerize with acrylonitrile. This was achieved by using azobisisobutyronitrile as the initiator and dimethyl sulfoxide as the solvent. Effects of copolymerization systems on monomer apparent reactivity ratios for acrylonitrile/ammonium itaconate copolymers were studied. The values of monomer apparent reactivity ratios were calculated by Kelen‐Tudos method. The apparent reactivity ratios in the aqueous suspension polymerization system are similar to those in the solution polymerization system at polymerization conversions of less than 18% [reactivity ratio of acrylonitrile (r_AN) = 0.47 ± 0.01, reactivity ratio of ammonium itaconate (r_AIA) = 3.08 ± 0.01]. At conversions of more than 50%, the changes of monomer apparent reactivity ratios become less prominent (r_AN = 0.68 ± 0.01, r_AIA = 2.47 ± 0.01). In water‐rich reaction medium [(H₂O/dimethylsulfoxide (DMSO) > 80/20)], the monomer apparent reactivity ratios are approximately equivalent to those in the aqueous suspension polymerization system. In DMSO‐rich reaction medium (DMSO/H₂O > 80/20), the apparent reactivity ratios are similar to those in the solution polymerization system. With an increase in the polarity of the solvent, the values of apparent reaction ratios both decrease. The values of apparent reaction ratios gradually tend to 1 with increasing the copolymerization temperature. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3920–3923, 2007     

Study on monomer reactivity ratios of acrylonitrile/itaconic acid in aqueous deposited copolymerization system initiated by ammonium persulfate

A single water-soluble initiator-ammonium persulfate (APS), not containing alkali metal ions, was first utilized to initiate copolymerization of acrylonitrile (AN)/itaconic acid (IA) in aqueous deposited copolymerization system. Monomer reactivity ratios of this polymerization system were investigated using element analysis method and Q–e schemes. It was found that the monomer reactivity ratios of AN/IA calculated from Q–e schemes are 0.505 (r _AN) and 1.928 (r _IA), while the monomer reactivity ratios of AN/IA in aqueous deposited copolymerization system at 60 °C are 0.64 (r _AN) and 1.37 (r _IA) calculated from Kelen–Tüdõs method, 0.61 (r _AN) and 1.47 (r _IA) from Fineman–Ross method. The three pairs of monomer reactivity ratios are in good agreement. With the increase of the polymerization temperature, the monomer reactivity ratios of AN and IA approach to unity, indicating that the aqueous deposited copolymerization of AN/IA has a tendency to ideal copolymerization. At lower polymerization conversion, the monomer reactivity ratios of AN and IA have hardly any changes. When the polymerization conversion is more than 5%, the monomer reactivity ratio of AN increases, while that of IA decreases.     

Kinetic study of copolymerization of acrylonitrile with ammonium acrylate

Ammonium acrylate was first used to successfully copolymerize with acrylonitrile. Kinetics of copolymerization of acrylonitrile with ammonium acrylate was investigated in a H₂O/dimethylsulfoxide (DMSO) mixture. The rate of copolymerization and particle size were measured. Kinetic equation of the copolymerization was obtained. Effect of copolymerization systems on monomer apparent reactivity ratios for acrylonitrile/ammonium acrylate copolymers was studied in comparison. Values of monomer apparent reactivity ratios were calculated by Kelen‐Tudos method. It has been found that monomer apparent reactivity ratios in water‐rich reaction medium [H₂O/DMSO>80/20] are approximately equivalent to those in aqueous suspension polymerization system. In DMSO‐rich reaction medium (DMSO/H₂O > 80/20), apparent reactivity ratios are similar to those in solution polymerization system. With an increase in polarity of solvent, values of apparent reaction ratios both decrease. The values of apparent reaction ratios gradually tend to 1 with increase in the copolymerization temperature. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4679–4683, 2006     

Degradation of acrylonitrile–ammonium itaconate copolymers

Acrylonitrile–ammonium itaconate copolymers were prepared by H₂O/dimethyl formamide suspension polymerization technique. Differential scanning calorimetry results of the degradation of acrylonitrile–ammonium itaconate copolymers in air are presented. The apparent activation energy of degradation of the copolymer was calculated using the Kissinger method. Effects of copolymerization conditions on the apparent activation energy of copolymer were studied. Increasing the dimethyl formamide concentration in the solvent mixture leads to a rapid increase in the degradation apparent activation energy of acrylonitrile–ammonium itaconate copolymer. The value of the degradation apparent activation energy of the copolymer synthesized in dimethyl formamide solvent increases up to 168.3 kJ mol^?1. The apparent activation energy decreases quickly along with an increase in ammonium itaconate concentration, and this change becomes less prominent as the weight ratio of ammonium itaconate/acrylonitrile goes beyond 6/94, ΔE_a = 89.4 ± 2.0 kJ mol^?1. The apparent activation energy shows a trend of increase with increasing copolymerization temperature. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1708–1711, 2005     

Studies of inverse emulsion copolymerization of (2-methacryloyloxyethyl) trimethyl ammonium chloride and acrylamide

Inverse emulsion copolymerization of (2-methacryloyloxyethyl) trimethyl ammonium chloride with acrylamide initiated with potassium persulfate has been studied dilatometrically. Aqueous monomer solutions were emulsified in kerosene with a blend of two surfactants (Span80 and OP10). The gel effect is evident from the increase of the molecular weight with conversion and also from the percentage of conversion versus time curves. Monomer reactivity ratios have been derived as r_AM = 0.38 and r_DMC = 1.69 at pH 6.8. The effects of initiator concentration, concentration, and composition of the monomer, emulsifier concentration, etc., on the polymerization rate and intrinsic viscosity of polymer have been examined. The rate of polymerization (R_p) can be represented by R_p I^0.52[M]^1.50[E]^0.38. The overall activation energy for the rate of polymerization is 66.0 kJ mol (40–65°C). Based on these experimental results, some aspects of the polymerization mechanism are discussed. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67:1005–1010, 1998     

Acrylonitrile/ammonium itaconate aqueous deposited copolymerization

Acrylonitrile/ammonium itaconate [AN/(NH₄)₂IA] aqueous deposited polymerizations were studied in this work. It shows that the polymerizations were influenced by various factors, especially the water solubility of AN. In the polymerization process, the system was as separated monomer and water phases, and AN transferred from monomer phase to water phase until the monomer phase disappeared. Because of the solubility of AN in water, the reactivity ratios of monomer calculated by Kelen‐Tudos method were different in various monomer contents. Although (NH₄)₂S₂O₈ was a water‐soluble initiator, there was a short amount of polymer formed in monomer phase. To inhibit the polymerization in monomer phase, two additives were used in the polymerization and experiment data indicated that the two inhibitors exert inhibitory role effectively in monomer phase. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 904–908, 2006     

Diffusion coefficient of DMSO in polyacrylonitrile fiber formation

A H₂O/dimethyl sulfoxide(DMSO) mixture was used as the coagulation bath for the wet‐spun process of acrylonitrile/ammonium itaconate copolymers fibers. Diffusion coefficient of DMSO in the protofibers prepared by acrylonitrile/ammonium itaconate copolymers was determined. It has been found that diffusion coefficient of DMSO outflow of the protofibers prepared by acrylonitrile/ammonium itaconate copolymers synthesized by the solution polymerization is highest compared with those of acrylonitrile/ammonium itaconate copolymers synthesized by H₂O/DMSO mixture suspension polymerization and the aqueous suspension polymerization. With an increase of copolymer concentration in the dope, diffusion coefficient of DMSO decreases continuously. Diffusion coefficient of DMSO increases along with the bath temperature, but the changes of diffusion coefficient values are less prominent as temperature goes beyond 60°C. When DMSO concentration in the coagulation bath was 55 wt %, the value of the diffusion coefficient of DMSO was minimal. Diffusion coefficient of H₂O increases with the jet stretch minus ratio increasing. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4447–4451, 2006     

A comparison of composition and sequence distribution of p(AM-MADQUAT) prepared by solution and inverse microemulsion polymerization

Acrylamide (AM)/2-(methacryloyloxy)ethyltrimethylammonium chloride (MADQUAT) copolymers were prepared by solution and inverse microemulsion polymerization using ammonium persulfate ((NH₄)₂S₂O₈)/sodium hydrosulfite (NaHSO₃) as redox initiator at 30 °C. The comonomer reactivity ratios, determined using the Kelen–Tudos (KT) method, were r _A = 0.30, r _M = 1.31 in solution and r _A = 0.63, r _M = 1.13 in the inverse microemulsion, respectively. The copolymer microstructure was deduced from the run number and the heterogeneity, based on reactivity ratios. It was found that copolymerization in the inverse microemulsion resulted in close to ideal copolymerization, giving almost random copolymers; copolymerization in solution resulted in some alternating copolymers. The copolymer compositions indicated that high-conversion samples obtained from the inverse microemulsion are much more homogeneous in composition compared with those obtained in solution. It was found that the composition distribution of the copolymer prepared by inverse microemulsion polymerization remained at approximately the feed ratio. The sequence distribution of the copolymer was predicted by first-order Markov statistical and Bernoulli statistical models, respectively. The results showed that the sequence distribution of the copolymer prepared by inverse microemulsion polymerization was almost random, which led to a wider cationic charge distribution and a microstructure that was coincident with the feed ratio.     

Effect of medium pH on the reactivity ratios in acrylamide acrylic acid copolymerization

The copolymerization reactivity ratios of acrylic acid and acrylamide are found at pH 5 and pH 2. Automatic continuous online monitoring of polymerization reactions (ACOMP) has been used for the first time to monitor the synthesis of polyelectrolytic copolymers. The composition drift during the reactions revealed that at pH 5, the acrylamide participates more in the copolymer, and at pH 2, the acrylic acid incorporates in the system at a higher ratio. The copolymerization data were analyzed by a recent error in variables (EVM) type calculation method developed for obtaining the reactivity ratios by on‐line monitoring and gave at pH 5 reactivity ratios r_Aam = 1.88 ± 0.17, r_Aac = 0.80 ± 0.07 and at pH 2 r_Aam = 0.16 ± 0.04, r_Aac = 0.88 ± 0.08. The results show that the reactivity ratios depend strongly on the pH of the medium. The effect of polyelectrolytic interactions on the reactivity ratios is discussed in detail. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 968–974, 2007     

Dispersion copolymerization of acrylonitrile‐vinyl acetate in supercritical carbon dioxide

Dispersion copolymerization of acrylonitrile‐vinyl acetate (AN‐VAc) had been successfully performed in supercritical carbon dioxide (ScCO₂) with 2,2‐azobisisobutyronitrile (AIBN) as a initiator and a series of lipophilic/CO₂‐philic diblock copolymers, such as poly(styrene‐r‐acrylonitrile)‐b‐poly(1,1,2,2‐tetrahydroperfluorooctyl methacrylate) (PSAN‐b‐PFOMA), as steric stabilizers. In dispersion copolymerization, poly(acrylonitrile‐r‐vinyl acetate) (PAVAc) was emulsified in ScCO₂ effectively using PSAN‐b‐PFOMA as a stabilizer. Compared with the precipitation polymerization (absence of stabilizer), the products prepared by dispersion polymerization possessed of higher yield and higher molecular weight. In addition, the particle morphology of precipitation polymerization was irregular, but the particle morphology of dispersion polymerization was uniform spherical particles. In this study, the effects of the initial concentrations of monomer and the stabilizer and the initiator, and the reaction pressure on the yield and the molecular weight and the resulting size and particle morphology of the colloidal particles were investigated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5640–5648, 2006     

Graft copolymerization of acrylamide–methylacrylate comonomers onto cellulose using ceric ammonium nitrate

The graft copolymerization of acrylamide–methylacrylate comonomers was carried out using ceric ammonium nitrate as initiator in the presence of nitric acid at 25 ± 1°C. The effects of feed molarity, feed composition, reaction time, and temperature on graft yield (%G) and other grafting parameters were investigated. The determination of rate of ceric (IV) ions disappearance as a function of feed molarity and reaction time was useful in the determination of the rate of ceric (IV) ions consumption during graft copolymerization. The graft yield (%G) in the presence of acrylamide increases because of the synergistic effect of acrylamide comonomer. The composition of the grafted chains (F_AAm) varies on varying the feed composition and reaction temperature but is almost constant during feed molarity variation. The Mayo and Lewis method was used to determine the reactivity ratios of acrylamide (r₁) and methylacrylate (r₂), which are 0.65 and 1.07, respectively. The product of reactivity ratio (r₁ r₂) is less then unity; hence, an alternate arrangement of comonomer blocks in the grafted copolymer chain is proposed. The rate of graft copolymerization of comonomers onto cellulose is second power to the concentration of comonomers and square root to the concentration of ceric ammonium nitrate. Suitable reaction steps for graft copolymerization of comonomers onto cellulose are proposed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2631–2642, 2002     

Aqueous deposited copolymerization of acrylonitrile with ammonium itaconate under magnetic field

Copolymerization of acrylonitrile(AN) with ammonium itaconate (AIA) initiated by ammonium persulfate (APS) was investigated in deionized water at 60°C under magnetic field(MF). The values of monomer apparent reactivity ratios were calculated by Kelen-Tüdõs method and the conversion was also measured. It has been found that the polymer radical group with an AIA unit at the chain end is considerably more active in the presence of MF, the conversion of solution polymerization of AN in the presence of MF is higher at the same ratio of AN/AIA. The molecular weight distribution (MWD) is narrower than that prepared without MF because of the orientation of their spin moments under MF. moreover, the fluctuation of the lifetime of propagating AN macroradicals is smaller. It is clear that the crystallization degree of powder polyacrylonitrile (PAN) prepared with MF is higher than that PAN obtained without MF. For the attained fibers coming from the dope treated under MF, the thermal properties become more stable, which also affects on the mechanical properties of the resultant fibers.     

Free‐radical copolymerization kinetics of acrylonitrile and methyl acrylate in [BMIM]BF4

The copolymerization of acrylonitrile (AN) and methyl acrylate (MA) was carried out in ionic liquid [BMIM]BF₄ in the presence of azobisisobutyronitrile (AIBN) as an initiator to investigate the polymerization kinetic, including the copolymerization rate, reactivity ratios, and activation energy. The copolymerization rate equation was established according to the effect of initiator and monomer concentrations on the conversion. The copolymerization rate R_p can be noted as , when the copolymerization was in the steady state. The apparent activation energy is 87.94 kJ/mol, while the value of that in the conventional organic solvent (DMF) is ∼ 81 kJ/mol. The reactivity ratios of the investigate system are r_AN = 0.36 and r_MA = 0.68. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4254–4257, 2006     

Copolymerization kinetics of acrylonitrile with amino ethyl‐2‐methyl propenoate in H2O/DMSO mixture

Amino ethyl‐2‐methyl propenoate (AEMP) was used successfully to copolymerize with acrylonitrile (AN). This was achieved by using azobisisobutyronitrile as the initiator. Kinetics of copolymerization of AN with AEMP was investigated in H₂O/dimethylsulfoxide (DMSO) mixture between 50 and 70 °C under N₂ atmosphere. The rate of copolymerization was measured. The kinetic equation of copolymerization system was obtained and the overall activation energy for the copolymerization system was determined. Values of monomer apparent reactivity ratios were calculated using Kelen–Tudos method. It has been found that the apparent reactivity ratios in aqueous suspension polymerization system are similar to those in solution polymerization system at polymerization conversion less than 25%. At conversion beyond 45%, the changes of monomer apparent reactivity ratios become less prominent. In water‐rich reaction medium (H₂O/DMSO > 70/30), monomer apparent reactivity ratios are approximately equivalent to those in aqueous suspension polymerization system. In DMSO‐rich reaction medium (DMSO/H₂O > 70/30), apparent reactivity ratios are similar to those in solution polymerization system. With an increase of polarity of solvent, values of apparent reaction ratios both decrease. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2095–2100, 2006     

Synthesis and polymerization of the acrylamide derivatives of fatty compounds

The Ritter reaction of plant oil triglycerides (such as soybean and sunflower oil) with acrylonitrile was used to introduce acrylamide functionality on the triglyceride. Acrylonitrile and triglycerides were reacted in the presence of H₂SO₄, and acrylamide derivatives were obtained in yields of 45 and 50% for sunflower oil and soybean oil, respectively. Radical initiated copolymerization of the acrylamide derivatives of the triglycerides with styrene produced semirigid polymers. Characterization of new monomers and polymers was done by ¹H‐NMR, ¹³C‐NMR, IR, and MS. The swelling behavior of the crosslinked network polymers was determined in different solvents. Glass transiton temperature (T_g) of the cured resin was also determined by differential scanning calorimeter to be 40°C for soybean based polymer and 30°C for sunflower‐based polymer. Homo‐ and copolymerization behavior of acrylamide derivatives of methyl oleate (MOA) and methyl 10‐undecenoate (MUA) were also investigated. The reactivity ratios of these monomers with respect to styrene were determined by the Fineman–Ross method using ¹H‐NMR spectroscopic data. The reactivity ratios were r_sty = 1.776; r_moa = 0512 for MOA, and r_sty = 1.142; r_mua = 0.507 for MUA, respectively. Photopolymerization behaviors of MOA and MUA were also investigated using the photoDSC technique and the rate of polymerization of MUA is higher than that of MOA under the same conditions. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 2264–2272, 2005     

Monomer apparent reactivity ratios for acrylonitrile/methyl vinyl ketone copolymerization system

Methyl vinyl ketone was firstly used to successfully copolymerize with acrylonitrile. This was achieved by using azobisisobutyronitrile as the initiator, and dimethyl sulfoxide as the solvent. Effect of copolymerization systems on monomer apparent reactivity ratios for copolymer of acrylonitrile with methyl vinyl ketone was studied for contrast. Values of monomer apparent reactivity ratios were calculated by Kelen–Tudos method. It has been found that the apparent reactivity ratios in aqueous suspension polymerization system were similar to those in solution polymerization system at polymerization conversion less than 20%. Beyond 50% of conversion, the changes of monomer apparent reactivity ratios become less prominent. In water‐rich reaction medium [(H₂O/dimethylsulfoxide (DMSO)>80/20), monomer apparent reactivity ratios were approximately equivalent to those in aqueous suspension polymerization system. In DMSO‐rich reaction medium (DMSO/H₂O > 80/20), apparent reactivity ratios were similar to those in solution polymerization system. Values of apparent reaction ratios both decreased when AN/MVK copolymer was synthesized in DMF and DMAc. The values of apparent reaction ratios gradually tend to 1 with increasing the copolymerization temperature. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4045–4048, 2006     

Organotin polymers: 10. Copolymerization parameters for di-(tri-n-butyltin) itaconate with methyl acrylate,ethyl acrylate,N-vinyl pyrrolidone and acrylonitrile

The monomer reactivity ratios for the copolymerization of di-(tri-n-butyltin) itaconate (M₁) with methyl acrylate (M₂), ethyl acrylate (M₂), N-vinyl pyrrolidone (M₂) and acrylonitrile (M₂) were found to be r₁ = 0.387, r₂ = 0.671; r₁ = 0.555, r₂ = 0.958; r₁ = 0.033, r₂ = 0.185 and r₁ = 0.441, r₂ = 0.425, respectively. Copolymerization reactions were carried out in solution at 60°C using 1 mol% AIBN, with copolymer compositions being determined by tin analysis. The Q and e values for di-(tri-n-butyltin) itaconate were calculated from the monomer reactivity ratios determined in the present and previous studies. The sequence distribution of the triad fractions for the systems studied were calculated at azeotropic compositions.     

4‐Acetamidophenyl acrylate copolymers with acrylonitrile and N‐vinyl‐2‐pyrrolidone: Synthesis,characterization, and reactivity ratios

4‐Acetamidophenyl acrylate (APA) was synthesized and characterized by IR, ¹H and ¹³C NMR spectroscopies. Homo‐ and copolymers of APA with acrylonitrile (AN) and N‐vinyl‐2‐pyrrolidone (NVP) were prepared by a free radical polymerization. All the copolymer compositions have been determined by ¹H NMR technique, and the reactivity ratios of the monomer pairs have been evaluated using the linearization methods Fineman–Ross, Kelen–Tudos, and extended Kelen–Tudos. Nonlinear error‐in‐variable model (EVM) method was used to compare the reactivity ratios. The reactivity ratios for copoly(APA–AN) system were APA(r₁) = 0.70 and AN(r₂) = 0.333, and for copoly(APA–NVP) system the values were APA(r₁) = 4.99 and NVP(r₂) = 0.019. Thermal stability and molecular weights of the copolymers are reported. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1919–1927, 2006     

Relative reactivities and graft distributions of polystyrene Macromers® in vinyl chloride copolymerization

Polystyrene macromonomers terminated with methacrylate, vinyl ether, or maleic half ester functionalities were evaluated in free radical initiated copolymerizations with vinyl chloride in aqueous suspension polymerization. Macromers® (M₁) terminated with methacrylate disappeared very rapidly in copolymerization with vinyl chloride (M₂). The relative reactivity ratio, r₂, was determined to be 0.05 in good agreement with literature values of about 0.04. Vinyl ether-terminated Macromers® had unexpectedly uniform reactivity with vinyl chloride in early conversion samples, but macromonomer conversion was incomplete. Macromers® having maleic half ester functionality were incorporated rapidly in vinyl chloride copolymerization at pH 2.5 (r₂ = 0.13). However, at pH 10 these Macromers® had reduced reactivity (r₂ = 0.34), which improved graft polymer uniformity. These Macromer® copolymerization relative reactivities are shown to be useful in predicting and controlling graft densities and graft polymer heterogeneity which influence morphology, processing, and mechanical properties.     

Reactivity ratios and copolymer properties of 2‐(diisopropylamino)ethyl methacrylate with methyl methacrylate and styrene

Free radical copolymerization kinetics of 2‐(diisopropylamino)ethyl methacrylate (DPA) with styrene (ST) or methyl methacrylate (MMA) was investigated and the corresponding copolymers obtained were characterized. Polymerization was performed using tert‐butylperoxy‐2‐ethylhexanoate (0.01 mol dm^?3) as initiator, isothermally (70 °C) to low conversions (<10 wt%) in a wide range of copolymer compositions (10 mol% steps). The reactivity ratios of the monomers were calculated using linear Kelen–Tüd?s (KT) and nonlinear Tidwell–Mortimer (TM) methods. The reactivity ratios for MMA/DPA were found to be r₁ = 0.99 and r₂ = 1.00 (KT), r₁ = 0.99 and r₂ = 1.03 (TM); for the ST/DPA system r₁ = 2.74, r₂ = 0.54 (KT) and r₁ = 2.48, r₂ = 0.49 (TM). It can be concluded that copolymerization of MMA with DPA is ideal while copolymerization of ST with DPA has a small but noticeable tendency for block copolymer building. The probabilities for formations of dyad and triad monomer sequences dependent on monomer compositions were calculated from the obtained reactivity ratios. The molar mass distribution, thermal stability and glass transition temperatures of synthesized copolymers were determined. Hydrophobicity of copolymers depending on the composition was determined using contact angle measurements, decreasing from hydrophobic polystyrene and poly(methyl methacrylate) to hydrophilic DPA. Copolymerization reactivity ratios are crucial for the control of copolymer structural properties and conversion heterogeneity that greatly influence the applications of copolymers as rheology modifiers of lubricating oils or in drug delivery systems. © 2015 Society of Chemical Industry