Binary copolymerizations of 8-methacryloxy-quinoline with methyl methacrylate, methyl acrylate, styrene and acrylonitrile

8-methacryloxy-quinoline monomer (MAQ) was prepared by the reaction of 8-hydroxyquinoline with either methacryloyl chloride or methacrylic acid in the presence of triethylamine and N, N′-dicyclohexylcarbodiimide, respectively. Its structure was confirmed by IR and 1 H-NMR spectroscopy. Binary copolymerization of this new monomer with methyl acrylate (MA), acrylonitrile (AN) methyl methacrylate (MMA), styrene(ST), were performed in Dimethylformamide, using 1 mol% azobisisobutyronitrile as initiator at 65 °C. The copolymer compositions were determined from nitrogen analysis except MAQ-AN with 1 H-NMR. Copolymerization Parameters for each system were calculated by both the Finemen-Ross and Kelen-Tüdös methods. The monomer reactivity ratios for the systems MAQ-MA, MAQ-AN, MAQ-MMA and MAQ-ST were found to be r1?=?0.695?±?0.036, r2?=?0.62?±?0.235; r1?=?0.273?±?0.087, r2?=?0.259?±?0.67; r1?=?0.356?±?0.015, r2?=?1.615?±?0.052 and r1?=?0.097?±?0.003, r2?=?0.339?±?0.027 respectively. The Q and e values for MAQ monomer were found to be 1.62 and 1.40.     

Graft copolymerization of acrylonitrile and methyl methacrylate monomer mixtures on crumb natural rubber

Graft copolymerization of mixtures of acrylonitrile and methyl methacylate on crumb natural rubber was carried out in toluene at 60°C. The nitrogen content of the grafted copolymer was determined by elemental analysis and used to estimate the composition of the copolymer samples. It was found that the amount of acrylonitrile monomeric units incorporated into the polymer was disproportionately lower than the acylonitrile content of the feed and explanations in terms of the e‐value of the monomers and the inherent heterogenous nature of the polymerization mixture were offered. The miscibility of the natural rubber‐g‐polyacrylonitrile‐co‐poly(methyl methacrylate) with poly(vinyl chloride) was studied by viscometry, differential scanning calorimetry, and phase contrast microscopy. It was found that the natural rubber‐g‐polyacrylonitrile‐co‐poly(methyl methacrylate) formed semimiscible blends with poly(vinyl chloride). © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1872–1877, 2002; DOI 10.1002/app.10474     

Graft copolymerization of vinyl monomers on modified cottons,XXI. Cu++/hydrazine hydrate redox system induced grafting of methyl methacrylate on periodate oxidized cellulose

Periodate oxidized cellulose was grafted with methyl methacrylate using hydrazine hydrate in presence and absence of Cu⁺⁺. The grafting reaction was favoured in presence of Cu⁺⁺ and it was advantageous to treat first the cellulose material with copper sulphate solution rather than to incorporate it in the polymerization system. The graft yields depended upon the concentrations of copper sulphate and hydrazine hydrate, pH, temperature, and time of polymerization as well as degree of oxidation of cellulose. There were optimal concentrations of copper sulphate (6–8 mmol/l) and hydrazine hydrate (2 mmol/l). A polymerization medium of pH 6 and a temperature of 60°C constituted to optimal pH and temperature for grafting. Oxidized cellulose proved to be more amenable to grafting as compared with unoxidized cellulose and the magnitude of grafting relied on the degree of oxidation. A tentative mechanism was also suggested for grafting of cellulose substrates with a vinyl monomer using a Cu⁺⁺-hydrazine hydrate redox system.     

Graft copolymerization of vinyl monomers with modified cotton. II. Grafting of acrylonitrile and methyl methacrylate on acetylated cotton

Ce(IV)-induced polymerization of acrylonitrile and methyl methacrylate with acetylated cotton having different acetyl contents was investigated. The extent of interaction between the cotton and monomer is dependent upon the acetyl content of the former as well as on the reaction conditions. Increasing the acetyl content caused a significant decrease in the graft yield. Increasing the acrylonitrile concentration was accompanied by a substantial increase in the graft yields. The same effect was found with the initiator up to a certain concentration, but beyond it there was a reversal. The rate of grafting increased by rising the temperature and follow the order 60° > 40° > 30°C. The Ce(IV) consumption during grafting is greater than that consumed during oxidation. The consumption of Ce(IV) by the cellulosic materials was favorably influenced by the concentrations of monomer and initiator, time, and temperature. Rates of grafting and Ce(IV) consumption during oxidation of acetylated cottons having different acetyl contents strongly support the postulated mechanism of grafting using the Ce(IV)–cellulose redox system. Ce(IV) oxidation had practically no effect on the acetyl groups (expressed as per cent combined acetic acid) of the modified cotton.     

Pentavalent vanadium ion-induced grafting of methyl methacrylate onto cotton cellulose

Graft polymerization of methyl methacrylate (MMA) onto cotton cellulose using vanadium pentanitrate as initiator was studied under a variety of conditions. The graft yield increased with increasing initiator concentration up to 8 mmole/l. and then decreased upon further increase in initiator concentration. Increasing MMA concentration from 1 to 5% was accompanied by a significant increase in the degree of grafting. The latter was also affected by the kind and concentration of the acid incorporated in the polymerization medium. Based on graft yields, the efficiency of the acids follows the order H₂SO₄ > HNO₃ > HClO₄. Replacement of the acid with isopropyl alcohol was also examined. An isopropyl alcohol concentration of 10% constitutes the optimal concentration for grafting. Maximum graft yield depends upon the polymerization temperature; it follows the order 50°C ≥ 60°C > 40°C > 30°C > 70°C. Reaction mechanisms for grafting in the presence of acid as well as in the presence of isopropyl alcohol are proposed.     

Grafting of acrylonitrile and methyl methacrylate from their binary mixtures on cellulose using ceric ions

Ceric ion‐initiated grafting on cellulose from a binary mixture of acrylonitrile and methyl methacrylate was carried out in heterogeneous and acidic conditions at 30 ± 0.1°C in a nitrogen atmosphere. To avoid the complexation of water molecules with Ce(IV) ions, the concentration of the nitric acid was taken to be more than the concentration of ceric ions. The effect of the feed concentration, reaction time, and ceric ions concentration on grafting were investigated at a fixed composition. To investigate the effect of monomer–monomer interactions on grafting, the graft copolymerization was also studied, using different feed compositions (f_AN) ranging from 0.25 to 0.80. In this range of feed composition, the synergistic effect of methyl methacrylate molecules has shown an important effect on acrylonitrile monomer and facilitate the incorporation of the acrylonitrile monomer into the grafted chains. The reactivity ratios of acrylonitrile and methyl methacrylate were calculated using the Mayo and Lewis method and were found to be 0.74 and 1.03, respectively. The average sequence lengths of the monomers (m̄M) were found to be dependent on the feed compositions and found to be arranged in alternate fashion in the grafted chains. The probability of the addition of a monomer (P_1,1) to the growing radicals on cellulose ended with its own type of monomer was found to be dependent on the feed composition. The composition of the grafted copolymers, homocopolymers, was determined by IR and elemental analysis for nitrogen. None of the grafted chain on cellulose was found to be made of a single type of monomer. The ceric ion consumption during grafting was found to be independent of the molarity of the feed but shown an appreciable change in the initial few hours of grafting. The variation in the values of the grafting parameters as a function of the reaction conditions is suitably explained. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 767–778, 2001     

Grafting vinyl monomers onto cellulose. IV. Graft copolymerization of methyl methacrylate onto modified cellulose using peroxydiphosphate as the initiator

The graft copolymerization of methyl methacrylate onto modified cellulose was studied at 60° causing peroxydiphosphate as the initiator. The rate of grafting in case of different modified cellulose was determined by varying peroxydiphosphate, monomer, nature of substrate, and temperature. The molecular weight of the isolated polymer has been determined, and the mechanism of grafting is discussed.     

Graft copolymerization of methyl methacrylate on holocellulose

Graft copolymerization of methyl methacrylate initiated by ceric ion in aqueous medium on bleached holocellulose was studied at 29°C. It was found that an increase in the concentration of ceric ion and oxidation of the holocellulose with aqueous potassium dichromate solution resulted in increased levels of incorporation of poly(methyl methacrylate) graft copolymer, but were associated with reductions in the efficiency of grafting. Thiol groups were introduced on the holocellulose by treatment with dilute thioglycollic acid solutions at 29°C. The influence on the level of grafting and on the molecular weight of the grafted polymer by the incorporated thiol groups on the substrate was examined.     

Graft copolymerization of vinyl monomers on modified cottons. III. Grafting of acrylonitrile and methyl methacrylate on cyanoethylated cotton by the ceric ion method

The interaction of acrylonitrile and methyl methacrylate with cyanoethylated cotton in the presence of ceric ion has been studied under a variety of conditions. Increasing the reaction time, the monomer concentration, and the temperature favorably influences the degree of grafting. The same holds true for initiator concentration up to a certain limit, after which a decrease in the graft yield was obtained. On the other hand, ceric consumption during grafting and oxidation increases by increasing the magnitudes of all these factors. However, the consumption during grafting is always higher than that during oxidation. The graft yields obtained with cyanoethylated cotton are greater than those of the control, being increased by increasing the degree of substitution (D.S.) of the cyanoethylated cotton, suggesting that the cyanoethyl groups afford additional sites of grafting. On the other hand, the ceric consumption during oxidation of cyano-ethylated cotton was much lower than that of the control, being increased also by increasing the D.S., indicating perhaps that ceric ion attacks the cyanoethylated cotton exclusively at the cyanoethyl groups. Based on these findings, a scheme for the mechanism of reaction of a vinyl monomer with cyanoethylated cotton was proposed.     

Terpolymerization reactions of N-acryloyloxyphthalimide or N-methacryloyloxyphthalimide with methyl acrylate,methyl methacrylate and acrylonitrile

Ternary copolymerization reactions of N-acryloyloxyphthalimide (NAP) or N-methacryloyloxyphthalimide (NMP) and acrylonitrile with methyl acrylate or methyl methacrylate were carried out in solution at 60°C in the presence of a free radical initiator. Experimental terpolymerization data agree well with calculations based on the Alfrey-Goldfinger equation. The determination of unitary, binary, and ternary azeotropies of the various systems studied was easily handled by a computer program. The results show that there is no ternary azeotropic composition for any terpolymer system studied. Selective unitary and binary azeotropic compositions were polymerized and the results show good agreement between the theoretical and experimental terpolymer composition in each case. The estimation of terpolymer compositions was carried out by ¹H NMR spectroscopy.     

Graft polymerization of acrylonitrile and methyl acrylate onto hemicellulose

Graft polymerizations of acrylonitrile onto both a commercial larchwood hemicellulose and a purified (low lignin) wheat straw hemicellulose could be initiated by ceric ammonium nitrate. The resulting hemicellulose-g-polyacrylonitrile (PAN) copolymers were fractionated by extraction at room temperature with dimethylformamide and dimethylsulfoxide. Fractions were characterized by determining both the wt % PAN in each polymer fraction and the molecular weight of grafted PAN. Saponification of the PAN component of hemicellulose-g-PAN gave a water-dispersible graft copolymer with good thickening properties for water systems. An absorbent polymer, similar to the starch-based absorbents (Super Slurpers), was produced when saponified hemicellulose-g-PAN was isolated by methanol precipitation and then dried. Larchwood hemicellulose was also graft-polymerized with methyl acrylate using ceric ammonium nitrate initiation, and the hemicellulose-g-poly(methyl acrylate) was extrusion-processed into a tough, leathery plastic. Although ceric ammonium nitrate could be used as an initiator for graft polymerizations onto low-lignin hemicelluloses, it was inert with crude wheat straw hemicellulose containing 11% lignin. The ferrous sulfate–hydrogen peroxide redox system was used to initiate graft polymerizations onto this high-lignin material, and properties of the resulting hemicellulose-g-poly(methyl acrylate) and saponified hemicellulose-g-PAN graft copolymers were evaluated.     

Organotin polymers. IV. Binary and ternary copolymerizations of tributyltin acrylate and methacrylate with styrene,allyl methacrylate,butyl methacrylate,butyl acrylate,and acrylonitrile

The monomer reactivity ratios for the copolymerization of tributyltin acrylate with styrene and allyl methacrylate have been found to be r₁ = 0.213, r₂ = 1.910 and r₁ = 0.195, r₂ = 2.257, respectively. Also, the copolymerization parameters of tributyltin methacrylate with styrene and allyl methacrylate were as follows: r₁ = 0.256, r₂ = 1.104 and r₁ = 2.306, r₂ = 1.013. Copolymerization reactions were carried out in solution at 70°C using 1 mole % AIBN, and the copolymer compositions were determined by tin analysis. Ternary copolymerization of the three systems butyl methacrylate–tributyltin methacrylate–acrylonitrile, butyl acrylate–tributyltin methacrylate–acrylonitrile, and styrene–tributyltin acrylate–acrylonitrile have been studied, and the terpolymer composition of each system was determined through tin and nitrogen analyses. The variation of instantaneous and average terpolymer composition with conversion fit satisfactorily the experimental results over a wide range of conversion.     

Graft copolymerization of methyl methacrylate and natural rubber

Graft copolymerization of natural rubber and MMA was carried out in the presence of Bz₂O₂ or AIBN as thermal initiator and hydrogen peroxide or benzophenone as photosensitizer. From the overall copolymerization product, the rubber–PMMA graft copolymer fraction was isolated from unreacted rubber and free PMMA fractions and composition characterization of the separated fractions was done by determination of rubber unsaturation. The efficiency of grafting under different conditions has been calculated and compared.     

Graft polymerization of methyl methacrylate onto gelatin

In order to extend the application of grafting for the modification of natural polymers, the graft polymerization of methyl methacrylate onto gelatin by radical initiators was studied in aqueous solution at temperatures between 60°C and 80°C. Among the initiators used (peroxy-sulfates, α,α′-azobisisobutylonitrile, and benzoyl peroxide), potassium peroxysulfate was found to be the most efficient initiator in this particular graft polymerization. From the kinetic data with this initiator, it was shown that (1) efficiency of grafting is higher at lower temperature; (2) a sharp increase in the efficiency of grafting occurs at the later period of the polymerization at high temperature, which is attributable to the combination between homopolymer and backbone gelatin; and (3) generally, the number of branches was small and the molecular weight of the branch polymer was high in this polymerization.     

Grafting vinyl monomers onto cellulose. I. Graft copolymerization of methyl methacrylate onto cellulose using quinquevalent vanadium ion

Graft copolymerization of methyl methacrylate on cellulosic materials with the use of quinquevalent vanadium as an initiator was studied. Increase of V⁵⁺ion concentration up to 0.0025 mole/liter increases graft yield, and with further increase of the initiator the graft yield decreases. The graft yield increases with increase of monomer concentration. The increase of acid concentration is accompanied by decrease of graft yield. A measurable increase in graft yield was observed with increase in temperature from 65 to 75°C. The graft yield is medium and substrate dependent. A suitable kinetic scheme has been pictured and a rate equation has been derived.