Polymerization Of Methacrylamide Research Articles

Experimental Design in Polymer Chemistry—A Guide towards True Optimization of a RAFT Polymerization Using Design of Experiments (DoE)

Despite the great potential of design of experiments (DoE) for efficiency and plannability in academic research, it remains a method predominantly used in industrial processes. From our perspective though, DoE additionally provides greater information gain than conventional experimentation approaches, even for more complex systems such as chemical reactions. Hence, this work presents a comprehensive DoE investigation on thermally initiated reversible addition–fragmentation chain transfer (RAFT) polymerization of methacrylamide (MAAm). To facilitate the adaptation of DoE for virtually every other polymerization, this work provides a step-by-step application guide emphasizing the biggest challenges along the way. Optimization of the RAFT system was achieved via response surface methodology utilizing a face-centered central composite design (FC-CCD). Highly accurate prediction models for the responses of monomer conversion, theoretical and apparent number averaged molecular weights, and dispersity are presented. The obtained equations not only facilitate thorough understanding of the observed system but also allow selection of synthetic targets for each individual response by prediction of the respective optimal factor settings. This work successfully demonstrates the great capability of DoE in academic research and aims to encourage fellow scientists to incorporate the technique into their repertoire of experimental strategies.

Effect of photoinitiator system on polymerization of methacrylamides

Effect of photoinitiator system on polymerization of methacrylamides

Synthesis and characterization of Polymethacrylamide-Clay nanocomposites

Polymethacrylamide intercalated hectorite clay nanocomposites were synthesized by the in situ free-radical polymerization method. The interlayer cation of hectorite clay was modified with cetyl pyridinium chloride and cetrimide, and their effects on the rate of polymerization of methacrylamide and the structure–property relationships of the resulting polymer nanocomposites were investigated. Fourier transform infrared spectroscopy showed a peak around 550 cm−1 that was due to the metal oxide stretching of hectorite clay in the polymer nanocomposites. High-resolution transmission electron microscopy determined the size of polymethacrylamide as 300 nm. X-ray diffraction was used for the determination of the intercalated products. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Poly(methacrylamide‐co‐acrylic acid) hydrogels for gastrointestinal delivery of theophylline. I. Swelling characterization

AbstractpH sensitive copolymeric hydrogels have been synthesized by free‐radical polymerization of methacrylamide and acrylic acid in aqueous medium. The gels were characterized by FTIR spectroscopy, thermogravimetric analysis, and swelling measurements. To determine the suitability of theses hydrogels for gastrointestinal oral delivery of model drug theophylline, their swelling behavior was investigated as a function of pH and various structural parameters such as the average molecular weight between crosslinks, crosslink density, and mesh size were calculated. Likewise initial, average and late time diffusion coefficients were also evaluated in simulating intestinal fluid of pH 6.8 at 37°C. The gel underwent sharp volume phase transition in the vicinity of pH 5.8. The mesh sizes of the hydrogel were between 8.4 and 9.2 Å in the collapsed state (pH range 1–2; SGF) and between 514 and 524 Å in the swollen state (pH range 7–8; SIF). The experimental data was found to fit well to Beren‐Hopfenberg equation thus suggesting that later part of swelling was chain relaxation controlled. The activation energy, as determined from Arrhenius equation was found to be 13.71 kJ mol−1. Likewise, enthalpy of mixing was also evaluated using Gibbs‐Helmholtz equation. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2995–3008, 2006

Flow through diffusion cell method: A novel approach to studyin vitro enzymatic degradation of a starch-based ternary semi-interpenetrating network for gastrointestinal drug delivery

A ter-polymeric semi-IPN has been synthesized by aqueous polymerization of methacrylamide in the presence of polyethylene glycol (PEG) and natural polysaccharides starch, and its enzymatic degradation has been studied in the phosphate buffer medium of pH 6.8 at the physiological temperature 37°C. With the increase in content of enzyme in the external solution and starch in the hydrogel, the degradation is enhanced while the extent of degradation is lowered with the increase in the amount of PEG in the hydrogel. The initial water content also affects the degradability of the polymer matrix. The degradation follows Michaelis–Menten kinetics and KM was found to be 3.92 × 10−5 mol dm−3. The hydrogel exhibits different degradation behavior when studied by “traditional degradation method” (TDM) and “flow through diffusion cell” (FTDC) method. The degradability is suppressed in FTDC method because of the absorption of amylase molecules onto filler particles. Finally the nature and size of the filler particles also affects the degradation behavior of hydrogels. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2975–2984, 2006

Poliwinyloamina zrodlem nowych mozliwosci rozwoju polimerow hydrofilowych

A review of a many-year-long research on the method of preparation of polyvinylamine (PVAm) precursor suitable for implementation into industry has been presented. Just a few years ago BASF introduced the production of poly(N-vinylformamide) (PNVF) from easily polymerizing N-vinylformamide (NVF). PNVF hydrolysis in mild conditions leads to PVAm [equation (4)], which is now available on the market as well as NVF, and PNVF. The results of own research concerning NVF structure investigation were discussed. 1 3 C NMR investigations let explain the higher reactivity of this monomer than of isomeric acrylamide. It was also found that PNVF hydrolysis in both acidic or basic environment was accompanied with ammonia evolution, not described up to now in the literature, what resulted in formation of some amount of γ-lactam units in PVAm [equation (5)]. The presence of NH 2 groups in PVAm, bonded with backbone, creates various possibilities of their functionalization (Scheme A). Low solubility of PVAm in organic solvents is really a disadvantage but carrying out the polyreactions and then modification reactions in microemulsions let overcome it. Polymerization of methacrylamide in microemulsion with subsequent crosslinking with glutaric aldehyde [reaction (6), Fig. 5 and 6] is given as an example of this manner. NVF polymerization in microemulsion is a subject of another paper of the authors.

Controlled/living polymerization of methacrylamide in aqueous media via the RAFT process

AbstractThe polymerization of methacrylamide (MAM) was performed in aqueous media via reversible addition fragmentation chain transfer (RAFT) polymerization with the dithiobenzoate chain‐transfer agent (CTA) 4‐cyanopentanoic acid dithiobenzoate (CTP) and 4,4′‐azobis(4‐cyanopentanoic acid) (V‐501) as initiator. The polymerization in unbuffered water at 70 °C with a CTP/V‐501 ratio of 1.5 was controlled for the first 3 h, after which the molecular weight distribution broadened and a substantial deviation of the experimental from the theoretical molecular weight occurred, presumably because of a loss of CTA functionality at longer polymerization times. Conducting the polymerization in an acidic buffer afforded a well‐defined homopolymer (Mn = 23,800 g/mol, Mw/Mn = 1.08). To demonstrate the controlled/living nature of the system, a block copolymer of MAM and acrylamide was successfully prepared (Mn = 33,800 g/mol, Mw/Mn = 1.25) from a polymethacrylamide macro‐CTA. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3141–3152, 2005

Stereocontrol during the free‐radical polymerization of methacrylamides in the presence of Lewis acids

AbstractThe effects of Lewis acids, that is, rare earth metal trifluoromethanesulfonates, on the free‐radical polymerization of N‐methylmethacrylamide (MMAM), N‐isopropylmethacrylamide (IPMAM), N‐tert‐butylmethacrylamide (tBMAM), N‐phenylmethacrylamide (PMAM), and methacrylamide were examined under various conditions. A catalytic amount of Yb(OSO2CF3)3 significantly affected the stereochemistry during the radical polymerization. Polymerization solvents strongly influenced the effect of the Lewis acids. Methanol was the best solvent for increasing the isotactic specificity during the polymerization of MMAM and IPMAM, whereas tetrahydrofuran was more effective for the tBMAM and PMAM polymerizations. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1027–1033, 2003

Polymerization of methacrylamide in the presence of ultrasound and peroxomonosulphate

Polymerization of methacrylamide has been carried out in the presence of ultrasound and peroxomonosulphate for the first time. The rate of polymerization and the rate of disappearance of peroxomonosulphate were followed simultaneously. A first order dependence on monomer and half order dependence with respect to peroxomonosulphate were found towards rate of polymerization. However, a first-order dependence on peroxomonosulphate was noted with rate of peroxomonosulphate disappearance. A suitable reaction scheme is suggested to fit with the experimental results. The composite rate constants for the polymerization were evaluated and compared for acrylamide and methacrylamide polymerization in the presence of ultrasound. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 524–529, 2000

Polymerization of methacrylamide in the presence of ultrasound and peroxomonosulphate

Polymerization of methacrylamide has been carried out in the presence of ultrasound and peroxomonosulphate for the first time. The rate of polymerization and the rate of disappearance of peroxomonosulphate were followed simultaneously. A first order dependence on monomer and half order dependence with respect to peroxomonosulphate were found towards rate of polymerization. However, a first-order dependence on peroxomonosulphate was noted with rate of peroxomonosulphate disappearance. A suitable reaction scheme is suggested to fit with the experimental results. The composite rate constants for the polymerization were evaluated and compared for acrylamide and methacrylamide polymerization in the presence of ultrasound.

Graft polymerization of methacrylamide onto wild silk fibers treated with an alkaline solution

Graft polymerization of methacrylamide was made on wild silk fibers (Chinese tussah silk fibers) and Indian muga silk fibers, and the level of polymer add-on was investigated. The polymer add-ons for these wild silk fibers were not as large as those obtained with commercial mulberry silk fibers. However, the level of polymer add-on for these wild silk fibers was increased by swelling treatment with a sodium hydroxide aqueous solution prior to the graft treatment.

Mechanical properties of tussah silk fibers treated with methacrylamide

Tussah silk fibers were treated with methacrylamide (MAA). The polymerization of MAA onto tussah silk fibers and the mechanical properties of the MAA-treated tussah silk fibers were investigated. The tanning agent contained in tussah silk fibers acted as an inhibitor to the radical polymerization of MAA. The alkali treatment enhanced the swelling of noncrystalline regions of the tussah silk fibers and promoted the polymerization of MAA onto the tussah silk fibers. The cross-sectional area of the MAA-treated tussah silk fiber was given by the sum of the cross-sectional area of the original silk fiber and that of the MAA polymer. Breaking load of the fibers was almost unchanged by the MAA treatment, while rigidity was markedly increased. Young's modulus of the MAA-treated tussah silk fibers decreased with decreasing volume fractions of the fiber in the MAA-treated tussah silk fibers. Young's modulus of the MAA polymer in the MAA-treated tussah silk fibers was estimated by extrapolating the relation between Young's moduli and the volume fractions of the fiber to zero volume fraction. Young's modulus of the MAA polymer in the MAA-treated tussah silk fibers was significantly larger than the modulus of a MAA polymer plate. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 2051–2057, 1997

Mechanical properties of tussah silk fibers treated with methacrylamide

Tussah silk fibers were treated with methacrylamide (MAA). The polymerization of MAA onto tussah silk fibers and the mechanical properties of the MAA-treated tussah silk fibers were investigated. The tanning agent contained in tussah silk fibers acted as an inhibitor to the radical polymerization of MAA. The alkali treatment enhanced the swelling of noncrystalline regions of the tussah silk fibers and promoted the polymerization of MAA onto the tussah silk fibers. The cross-sectional area of the MAA-treated tussah silk fiber was given by the sum of the cross-sectional area of the original silk fiber and that of the MAA polymer. Breaking load of the fibers was almost unchanged by the MAA treatment, while rigidity was markedly increased. Young's modulus of the MAA-treated tussah silk fibers decreased with decreasing volume fractions of the fiber in the MAA-treated tussah silk fibers. Young's modulus of the MAA polymer in the MAA-treated tussah silk fibers was estimated by extrapolating the relation between Young's moduli and the volume fractions of the fiber to zero volume fraction. Young's modulus of the MAA polymer in the MAA-treated tussah silk fibers was significantly larger than the modulus of a MAA polymer plate. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 2051–2057, 1997

Changes in fiber structure of Japanese oak silk fibers by the treatment with methacrylamide

Changes in the fiber structure and properties of Japanese oak silk fibers treated with methacrylamide (MAA) were investigated. The cross-sectional area of the Japanese oak silk fiber impregnated with the MAA polymer was given by the sum of the cross-sectional area of the original silk fiber and that of the MAA polymer. Tensile strength and Young's modulus of the Japanese oak silk fibers impregnated with the MAA polymer decreased with increasing polymer add-on. Scanning electron microscopic observations of fracture surfaces of Japanese oak silk fibers impregnated with the MAA polymer revealed that the silk fibers were split into fibrils by the polymerization of MAA infused in the fibers. Wide-angle x-ray diffraction measurements suggested that the destruction of crystallites in the fibers occurred homogeneously, independent of the sizes of the crystallites, by the MAA treatment.

Influence of Pigments on Graft Polymerization of Methacrylamide onto Wild Silk Fibers

Abstract Graft polymerization of methacrylamide (MAA) onto wild silk fibers was performed and the influence of pigments on graft polymerization was investigated. The pigments of Chinese oak silk and Japanese oak silk inhibited the polymerization of MAA. The inhibitory power of the pigments of Chinese oak silk was serious as compared with the pigments of Japanese oak silk. Therefore, MAA polymer add-on of Chinese oak silk fibers became smaller than that of Japanese oak silk fibers.

Mechanical properties of silk fibers treated with methacrylamide

Tussah silk fibers were treated with methacrylamide (MAA). The polymerization of MAA onto tussah silk fibers and the mechanical properties of the MAA-treated tussah silk fibers were investigated. The tanning agent contained in tussah silk fibers acted as an inhibitor to the radical polymerization of MAA. The alkali treatment enhanced the swelling of noncrystalline regions of the tussah silk fibers and promoted the polymerization of MAA onto the tussah silk fibers. The cross-sectional area of the MAA-treated tussah silk fiber was given by the sum of the cross-sectional area of the original silk fiber and that of the MAA polymer. Breaking load of the fibers was almost unchanged by the MAA treatment, while rigidity was markedly increased. Young's modulus of the MAA-treated tussah silk fibers decreased with decreasing volume fractions of the fiber in the MAA-treated tussah silk fibers. Young's modulus of the MAA polymer in the MAA-treated tussah silk fibers was estimated by extrapolating the relation between Young's moduli and the volume fractions of the fiber to zero volume fraction. Young's modulus of the MAA polymer in the MAA-treated tussah silk fibers was significantly larger than the modulus of a MAA polymer plate.

Aqueous Polymerization of Methacrylamide Initiated by Glycolic Acid-Ceric Ammonium Sulfate Redox System

Abstract The aqueous polymerization of methacrylamide (MA) initiated by the glycolic acid (GA)-Ce(IV) redox system was studied in sulfuric acid medium at 35 ± 0.2°C under a nitrogen atmosphere. The rate of monomer disappearance was found to be proportional to [MA]1 [Ce(IV)]1/2 [GA]1/2, and the rate of ceric ion disappearance was proportional to [GA] and [Ce(IV)] but independent of [MA]. The rate of polymerization increased with increasing temperature in the 30 to 50°C range. The activation energy was found to be 43 kJ/mol. The effect of increasing [H2SO4] on the polymerization was also studied. A kinetic scheme involving initiation by free radicals generated from the redox reaction between GA and Ce(IV) and termination by bimolecular reaction of macroradicals has been suggested.

Polymerization of Methacrylamide Initiated by Ceric Ion-Citric Acid Redox System

Abstract Homogeneous polymerization of methacrylamide initiated by the ceric ammonium sulfate-citric acid (CA) redox pair has been investigated and reported at 35 ± 0.2°C under nitrogen atmosphere. The initiation was caused by the free radical generated by the decomposition of the complex formed between ceric ion and citric acid. The rate of monomer disappearance was found to be proportional to [CA]0.4, [Ce0.4+]0.65, and [Monomer]1 The rate of ceric ion disappearance was directly proportional to the ceric ion concentration but independent of the monomer concentration. The initial rate was independent of [H2SO4]. The activation energy of the system was found to be 21.4 kJ/mol.

Aqueous polymerization of methacrylamide initiated by potassiumpersulfate-L-cystein hydrochloride redox system

The aqueous polymerization of methacrylamide initiated by potassiumpersulfate-L-cystein hydrochloride redox system has been studied at 35±0.01 ‡C under nitrogen atmosphere. The initial rate of polymerization has been found to be directly proportional to the monomer and activator concentration, in the range of 1.0 × 10−1 to 4.0 × 10−1 mol dm−3 and 1.25 × 10−3 to 5.0 × 10−3 mol dm−3 respectively. The order with respect to initiator has been found to be 0.5, indicating thereby that the termination takes place by bimolecular process. The overall energy of activation has been found to be 53±1 KJ/mol.

Polymerization of Methacrylamide Initiated by the Persulfate/Thiolactic Acid Redox System

Abstract The aqueous polymerization of methacrylamide initiated by the ammonium persulfate/thiolactic acid redox system has been studied at 35 ± 0.2°C. The rate of polymerization is governed by the expression, Rp + Kp [MAA] 1.33 [TLA]0.22 [ammonium persulfate]0.6. The deviations from normal kinetics are discussed. A tentative mechanism of initiation is given. The temperature dependence of the rate of polymerization has been studied over the range 30–55°C. The overall activation energy of polymerization is 10.4 kcal/mole.