Water-soluble copolymers: 21. Copolymers of acrylamide with 2-acrylamido-2-methylpropanedimethylammonium chloride: Synthesis and characterization

The copolymerization of acrylamide (AM) with 2-acrylamido-2-methylpropanedimethylammonium chloride (AMPDAC) has been studied in the range from 40 to 90% AM in the feed. The value of r₁r₂ has been determined to be 0.19 for the AM-AMPDAC pair. The copolymer compositions have been determined from elemental analysis and ¹³C n.m.r. The molecular weights of the copolymers were measured by low-angle laser light scattering, and ranged from 1.7–3.6 × 10⁶. Furthermore, the molecular weights were found to be relatively unaffected by monomer feed ratios. The copolymer microstructures, including run numbers and sequence distributions, were calculated from the reactivity ratios. These model structures are utilized for assessment of structure/dilute solution property relationships reported in a subsequent paper in this series.     

Synthesis and characterization of functional copolymer of Linalool and vinyl acetate: A kinetic study

Linalool (LIN) and vinyl acetate (VA) were copolymerized by benzoyl peroxide (BPO) in p‐xylene at 60°C for 90 min. The system follows nonideal kinetics: R_pα[I]^0.6[LIN]^1.2[VA]^1.1. It results in the formation of alternating copolymer as evidenced from reactivity ratios as r₁ (VA) = 0.01, r₂ (LIN) = 0.0015, which have been calculated by Kelen–Tudos method. The overall activation energy is 82 kJ/mol. The FTIR spectrum of the copolymer shows the presence of the band at 3425 cm^?1 due to alcoholic group of LIN and at 1641 cm^?1 due to >C?O group of VA. The ¹H‐NMR spectrum shows peaks at 7.0–7.7 δ due to hydroxy proton of LIN and at 1.0–1.4 δ due to acetoxy protons of VA. ¹³C‐NMR spectrum of copolymer shows peaks at 167 ppm due to acetoxy group and at 75–77 ppm due to C? OH group. The Alfrey–Price Q–e parameters for LIN has been calculated as Q₂ = 1.24 and e₂ = 3.11. The copolymer is highly thermally stable and has a glass transition temperature (T_g) of 85°C, evaluated from DSC studies. The mechanism of copolymerization has been elucidated. This article also reports measurement of Mark–Houwink constants in THF at 25°C by means of GPC as α = 0.8 and K = 3.0 × 10^?4 dl/g. The thermal decompositions of copolymer are established with the help of TGA technique. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1134–1143, 2004     

Determination of Mark–Houwink parameters of ethylene–norbornene copolymers and molecular characteristics estimation

Ethylene–norbornene copolymers (ENC) with ～ 50%, ～ 25% and ～ 15% norbornene (NB) fraction in a wide range of molecular weight were produced by metallocene catalysts. By coupling the gel permeation chromatography (GPC) with the intrinsic viscosity data in 1,2,4‐trichlorobenzene (TCB)at 150°C, the Mark–Houwink parameters of ENC were determined and compared with previous classical analysis using polyethylene's relative parameters. The results indicated that parameter K was considerably increased with decreasing NB fraction in ENC but parameter α was only increased slightly. Furthermore, the structure characteristics and correlative rheological parameters of resultant ENC were also calculated and discussed by the Stockmayer–Fixman analysis. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Synthesis and characterization of functional copolymers of citronellol with butylmethacrylate initiated by benzoyl peroxide

Benzoyl peroxide (BPO)‐initiated free radical copolymerization of citronellol with butylmethacrylate (BMA) in xylene at 80°C ± 0.1°C under the inert atmosphere of nitrogen has been studied. The kinetics expression is R_p α [I]^0.5±0.27 [citronellol]^1.0±0.13 [BMA]^1.0±0.18. The overall activation energy has been calculated as 65 kJ/mol. Bands at 3436 and 1732 cm^?1 in the FTIR spectrum of the copolymer(s) have indicated the presence of hydroxy, ester group of citronellol and butylmethacrylate, respectively. The ¹H‐NMR spectrum shows peaks at 7.0–7.7 δ due to ? OH proton of citronellol and at 3.2–4.0 δ due to ? OCH₂ proton of butylmethacrylate. The molecular weight M_v and η_int of the copolymers have been measured with the help of gel permeation chromatography in tetrahydrofuran at 25°C to calculate Mark‐Houwink constants as K = 2.68 × 10^?4 and α = 0.34 ± 0.40. The alternating nature of the copolymer is confirmed by reactivity ratios r₁ (BMA) = 0.023 ± 0.004 and r₂ (Citronellol) = 0.0025 ± 0.22. The Alfrey‐Price Q‐e parameters for citronellol have been calculated as Q₂ = 0.13 and e₂ = –1.28. Thermal decompositions of copolymer are evaluated with the help of thermal gravimetric analysis technique. The mechanism of copolymerization has been elucidated. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

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     

Water‐soluble copolymers from functionalized monomers (sodium o‐ and p‐methacryloylaminophenylarsonate): Synthesis and characterization

Copolymers of sodium o‐methacryloylaminophenylarsonate (o‐MAPHA‐Na) 1 and p‐methacrylolylaminophenylarsonate (p‐MAPHA‐Na) 2 with sodium acrylate (AA‐Na) 3 , sodium methacrylate (AM‐Na) 4 and acrylamide (AAD) 5 were prepared by free radical polymerization in aqueous media at 70°C using potassium persulfate (K₂S₂O₈) as the initiator. The total monomer concentration was carried out at 0.5M and the feed ratio ( M₁ : M₂ ) was varied from 10 : 90 to 90 : 10 mol%. The kinetic study was carried out by dilatometric method. The copolymer compositions were calculated by arsenic content in the copolymers. The As content (ppm) was determined by atomic absorption spectrometry (AAS). The reactivity ratios (r₁, r₂) were estimated by the Kelen‐Tüdös linearization method as well as error‐in‐variables method using the computer program RREVM®. In all cases, r₁ < 1 and r₂ > 1, indicating a tendency to form random copolymers. The values suggest that the copolymers contain a larger proportion of comonomer (i.e., AA‐Na, AM‐Na, or AAD). Weight‐average molar masses (M _w) of copolymers were determined by multi‐angle light scattering. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Preparation,characterization, and properties of cellulose–polyacrylamide graft copolymers

Graft copolymers of acrylamide on cellulose materials (α‐cellulose 55.8%, DP 287.3) obtained from Terminalia superba wood meal and its carboxymethylated derivative (DS 0.438) were prepared using a ceric ion initiator and batch polymerization and modified batch polymerization processes. The extent of graft polymer formation was measured in graft level, grafting efficiency, molecular weight of grafted polymer chains, frequency of grafting as a function of the polymerization medium, and initiator and monomer concentrations. It was found that the modified batch polymerization process yielded greater graft polymer formation and that graft copolymerization in aqueous alcohol medium resulted in enhanced levels of grafting and formation of many short grafted polymer chains. Viscosity measurements in aqueous solutions of carboxymethyl cellulose‐g‐polyacrylamide copolymer samples showed that interpositioning of polyacrylamide chains markedly increased the specific viscosity and resistance to biodegradation of the graft copolymers. The flocculation characteristics of the graft copolymers were determined with kaolin suspension. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 913–923, 2003     

Urea‐induced conformational changes of chitosan molecules and the shift of break point of Mark–Houwink equation by increasing urea concentration

Chitosan solutions of the same 83% degree of deacetylation (DD) but different weight average molecular weights (M_ws) (78–914 kDa) in 0.01M HCl containing different concentrations of urea (0–6M) were prepared. Intrinsic viscosity ([η]) and weight average molecular weight (M_w) of chitosan were measured with a capillary viscometer and light scattering, respectively. Mark–Houwink exponent a was used as the parameter of conformational index. The Mark–Houwink exponent a increased with increasing concentrations of urea. When solutions contained 0, 2, 3, 4, and 6M urea, the value of a increased from 0.715 to 0.839, 0.894, 1.000, and 1.060, respectively. This indicates the occurrence of urea‐induced conformational transitions of chitosans. The break point shifted from 223 kDa in solutions containing no urea to 280 kDa in 2M urea solutions, to 362 kDa in 4M urea solutions and further to 481 kDa in 6M urea solutions. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 452–457, 2000     

Microstructure analysis of methyl acrylate/methyl methacrylate copolymers by two‐dimensional NMR spectroscopy

Methyl acrylate (A)/methyl methacrylate (B) copolymers of different compositions were synthesized in bulk at 50°C and the compositions were determined from ¹H NMR spectra. Reactivity ratios were optimized using the least square methodology. Compositional and configurational assignments were done using two‐dimensional (2D) Heteronuclear Single Quantum Correlation (HSQC) and Total Correlation Spectroscopy (TOCSY) experiments. Methylene proton and carbon resonances were assigned for compositional and configurational sensitivity at tetrad level. Carbon resonances of methine group of methyl acrylate were assigned for compositional sensitivity up to triad level with the help of 2D HSQC spectra. α‐Methyl group of methyl methacrylate was assigned up to triad level of compositional and configurational placements for carbon and proton resonances by 2D HSQC spectroscopy. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1437–1445, 2006     

丙烯酰胺与2-甲基丙烯酰氧乙基三甲基氯化铵共聚合竞聚率及Q-e值的研究

采用双官能度过氧化物-NaHSO3氧化还原引发剂,进行丙烯酰胺(AM:M2)与2-甲基丙烯酰氧乙基三甲基氯化铵(DMC:M1)的水溶液共聚合,制得了阳离子型聚丙烯酰胺P(AM-DMC),通过红外光谱对共聚物结构进行了表征;对聚合物进行元素分析得到氮的总含量并利用莫尔法对阳离子度进行了测定,运用不同的方法计算了单体的竞聚率,并对其值进行了比较,得到单体竞聚率的平均值r1=1.8641,r2=0.2637;运用Alfrey-Price方程计算得到了DMC的Q-e值.     

Synthesis and characterization of N‐acryloylcarbazole/methyl methacrylate copolymers

Copolymers of N‐acryloylcarbazole (A) and methyl methacrylate (M) were synthesized in different in‐feed ratios. The composition of the copolymer was determined by the help of ¹H NMR spectrum. The comonomer reactivity ratios determined by Kelen‐Tudos (KT) and nonlinear error‐in‐variables methods were r_A = 1.12 ± 0.16, r_M = 0.94 ± 0.14, and r_A = 1.05, r_M = 0.90, respectively. Complete spectral assignments of the ¹H and ¹³C ¹H NMR spectra of the copolymers were done by the help of distortionless enhancement by polarization transfer (DEPT) and two‐dimensional NMR techniques, such as heteronuclear single quantum coherence (HSQC), total correlation spectroscopy (TOCSY), and heteronuclear multiple bond correlation (HMBC). The methine, α‐methyl, and carbonyl carbon resonances were found to be sequence sensitive. The signals obtained were broad because of the restricted rotation of bulky carbazole group and the quadrupolar effect of nitrogen present in carbazole moiety. Glass transition temperatures (T_g) were determined by differential scanning calorimetry and were found to be characteristic of copolymer composition. As the N‐acryloylcarbazole content increases, the T_g increases from 378.3 K for poly(methyl methacrylate) to 430.4 K for poly(N‐acryloylcarbazole). Variation in T_g with the copolymer composition were found to be in good agreement with theoretical values obtained from Johnston and Barton equations. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2667–2676, 2006     

Phenyl methacrylate-glycidyl methacrylate copolymers: synthesis, characterization and reactivity ratios by spectroscopic methods

The free-radical polymerization of phenyl methacrylate and glycidyl methacrylate was carried out at 70°C in the presence of benzoyl peroxide using 2-butanone as the solvent. The copolymer compositions of seven copolymer samples with different feed compositions as well as the tacticities were determined by ¹H nuclear magnetic resonance spectroscopy. The results were used to calculate the reactivity ratios by the Kelen-Tudos method, which were found to be r₁ = 1.57 ± 0.56 and r₂ = 0.84 ± 0.51. The homo- and copolymers were also characterized by Fourier-transform infra-red and ¹³C nuclear magnetic resonance spectroscopic methods. , and polydispersity indices of the copolymers were determined using gel permeation chromatography.     

Synthesis,characterizations and thermal behavior of methyl methacrylate and N‐(p‐carboxyphenyl) methacrylamide/acrylamide copolymers

The synthesis, characterization, and thermal properties of copolymers of methyl methacrylate (MMA) and N‐(p‐carboxyphenyl) methacrylamide/acrylamide (CPMA/CPA) are described. The copolymerization was carried out in solution by taking different mole fractions (0.1–0.5) of CPMA/CPA in the initial feed using azobisisobutyronitrile as an initiator and dimethylformamide as a solvent at 60°C. The copolymer composition was determined from ¹H‐NMR spectra by taking the ratio of the proton resonance signal due to the  OCH₃ of MMA (δ = 3.59 ppm) and the aromatic protons (δ = 7.6–7.8 ppm) of CPMA/CPA. The monomer reactivity ratios of MMA:CPMA and MMA:CPA were determined using the Fineman Ross and Kelen Tudos methods and were found to be 1.32 ± 0.01 [MMA], 1.11 ± 0.02 [CPMA], 2.60 ± 0.01 [MMA], and 0.20 ± 0.01 [CPA]. Incorporation of these comonomers in the MMA backbone resulted in an improvement in the glass‐transition temperature and thermal stability. The percent char also increased with the increase of CPMA/CPA content in the copolymers. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 259–267, 2000     

Synthesis, characterization polymerization and antibacterial properties of novel thiophene substituted acrylamide

Ethyl 2-acrylamido-4,5,6,7-tetrahydrobenzo [b] thiophene-3-carboxylate (ETTCA) has been synthesized and its structure has been elucidated by elemental analysis and spectral tools. Free radical polymerization of (ETTCA) has been conducted in several solvents using azobisisobutyronitrile (AIBN) as an initiator. The kinetic parameters of polymerization of the ETTCA were investigated, and it was found that the polymerization reaction follows the conventional free radical scheme. The overall activation energy of polymerization ΔE was determined (ΔE = 45.11 kJ mol⁻¹). The copolymerization of ETTCA with three conventional monomers was carried out in dioxane at 65 °C. The monomer reactivity ratios for the copolymerization of ETTCA with methyl methacrylate (MMA), vinyl acetate (VA) and vinyl ether (VE) were calculated. Thermal stability of the ETTCA polymer and its copolymers were investigated by thermogravimetric analysis. It has been found that the prepared polymer (PETTCA) and its copolymers with VA have moderate biological activity and highly dependent on the copolymer composition.