Different Degrees Of Quaternization Research Articles

Poly(vinyl pyridine) and Its Quaternized Derivatives: Understanding Their Solvation and Solid State Properties

A series of N-methyl quaternized derivatives of poly(4-vinylpyridine) (PVP) were synthesized in high yields with different degrees of quaternization, obtained by varying the methyl iodide molar ratio and affording products with unexplored optical and solvation properties. The impact of quaternization on the physicochemical properties of the copolymers, and notably the solvation properties, was further studied. The structure of the synthesized polymers and the quaternization degrees were determined by infrared and nuclear magnetic spectroscopies, while their thermal characteristics were studied by differential scanning calorimetry and their thermal stability and degradation by thermogravimetric analysis (TG-DTA). Attention was given to their optical properties, where UV-Vis and diffuse reflectance spectroscopy (DRS) measurements were carried out. The optical band gap of the polymers was calculated and correlated with the degree of quaternization. The study was further orientated towards the solvation properties of the polymers in binary solvent mixtures that strongly depend on the degree of quaternization, enabling a better understanding of the key polymer (solute)-solvent interactions. The assessment of the underlying solvation phenomena was performed in a system of different ratios of DMSO/H2O and the solvatochromic indicator used was Reichardt’s dye. Solvent polarity parameters have a significant effect on the visible spectra of the nitrogen quaternization of PVP studied in this work and a detailed path towards this assessment is presented.

Effect of Trimethyl Chitosan with Different Degrees of Quaternization on the Properties of Tablets Prepared using Charged Model Drugs

Trimethyl chitosan (TMC) has demonstrated effectiveness as an absorption enhancer for hydrophilic and high molecular weight (MW) drugs across the intestinal epithelium. However, the effects of degrees of quaternization (DQ) of TMC on the absorption of negatively and positively charged drugs have not been investigated. This investigation aimed to determine the properties of the tablets formulated using TMC with different DQ. In this study, TMC with DQ of 20 % (TMC-20), 40 % (TMC-40) and 60 % (TMC-60) were synthesized and subsequently characterized. Cetirizine dihydrochloride (CHC) and hyoscine butylbromide (HBB) were used as negatively and positively charged model drugs. Eight tablet formulations were prepared using the wet granulation method. The formulated tablets were evaluated regarding their properties in terms of thickness and hardness, weight variation, disintegration time, and dissolution profile. These tablets were evaluated according to the standards set by the United States Pharmacopeia (USP41) guidelines. The results showed that TMC with all DQ have the MW and an intrinsic viscosity less than starting chitosan. The MW and an intrinsic viscosity of the synthesized TMC decreased with increasing DQ. In order to evaluate the effect of TMC with various DQ on the properties of the formulated tablets, all tablet formulations prepared had good characteristics and were found to be within the acceptable range based on the requirements of USP. In conclusion, TMC had a minor retarding effect on the dissolution profiles of CHC from the formulated tablets. Still, TMC was able to significantly delay the release of HBB from the formulated tablets (p > 0.05). When TMC with various DQ were compared, TMC-60 showed higher drug release than TMC-20 and TMC-40. In our study, we observed a possible interaction between the model drugs and TMC. This warrants the need for further studies. HIGHLIGHTS Degree of quaternization represents the charge density of trimethyl chitosan (TMC) Degradation of the polymer backbone occurred in the synthesis reaction step TMC affects dissolution profiles of a negative charged drug Ionic interaction and viscous gel layer of TMC affects the model drug release

Antifungal properties of poly[2-(dimethylamino)ethyl methacrylate] (PDMAEMA) and quaternized derivatives

A series of poly[2-(dimethylamino)ethyl methacrylate]s (PDMAEMAs) of different molar mass were synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization. The polymers were subsequently treated with two different alkyl halides (1-iodobutane (BuI) and iodomethane (MeI)) to obtain a library of 21 PDMAEMAs with different degree of quaternization (DQ). This is the first report where the antifungal activity of these polymers is assessed for different fungi relevant in biomineralization and aesthetic biodeterioration of stone surfaces. The antifungal activity was assessed with the minimum inhibitory concentration (MIC), the minimum fungicidal concentration (MFC) and the mycelia growth inhibition in plate for the most promising materials. The obtained results demonstrated that all evaluated polymers possess certain level of antifungal activity against the evaluated fungi (even unquaternized PDMAEMAs). However, polymers of low molar mass (series III) revealed predominantly fungicidal activity at low values of MFC (from 2500 to 9.7 μg mL−1). Unexpectedly, the performed mycelia growth inhibition tests showed that the DQ has a less significant effect on the antifungal properties of the polymers than the polymer molar mass. Hence, the antifungal activity of these polymers may depend to a great extent on the physiological and morphological characteristics of the fungi, wherein the best antifungal activity was observed in III-M2, III-B1 and III-B2. It is worth mentioning that this detailed screening contributes to a better understanding of PDMAEMA-based composites that can be utilized in the development and optimization of low-cost and accessible antimicrobial protective coatings for petrous surfaces in cultural heritage monuments or modern buildings.

Enhancement of alkaline conductivity and chemical stability of quaternized poly(2,6-dimethyl-1,4-phenylene oxide) alkaline electrolyte membrane by mild temperature benzyl bromination.

A series of quaternized polyphenylene oxide (QPPO) based alkaline electrolyte membranes with different degrees of quaternization were synthesized via a benzyl bromination method at mild temperature (75 °C). Quite a high hydroxide conductivity under the reduced water uptake and swelling was exhibited by this method. When the degree of bromination measured from 1H NMR analysis was 30%, the corresponding hydroxide ion conductivity was 0.021 S cm−1. The chemical stability of the QPPO membranes was excellent, showing only 3% weight loss in 3 M NaOH solution during 1 month. The fuel cell performance test under H2/O2 exhibited the power density of 77 mW cm−2 and the current density of 190 mA cm−2 at 70 °C. Such excellent properties of QPPO membranes resulted from the achievement of the quaternization at the benzyl position, specifically.

Spontaneous Degrafting of Weak and Strong Polycationic Brushes in Aqueous Buffer Solutions

Polymers grafted to substrates have traditionally been considered stable because of the covalent bonds that hold the polymers attached to the substrate. However, several recent reports have indicated that grafted polymers may detach from substrates under specific conditions. In this work, we report on a systematic study of polymer degrafting involving polycationic brushes with different degrees of quaternization (DQ, mol %), which have been incubated in three different buffer solutions (pH 4, 7.4, and 9) with the same ionic strength of 0.05 M. We have varied the molecular weight (MW) and grafting density (σ) of the polymer brushes using a combinatorial setup to examine the effect of MW, σ, and DQ on polymer degrafting. Furthermore, we explored the effect of the bonding environment at the base of the initiator (mono- vs. tri-functional) of the grafted polymer layer at the substrate on the overall stability of polymer brushes on the substrate. The two major findings in this paper are (1) degrafting of polyc...

Stability of cationic and amphoteric derivatives of mannan from the yeast Candida albicans

Infection with Candida albicans can prove lethal in immuno-compromised patients. It is imperative to develop a vaccine against this common organism. The amphoteric derivatives of the mannan component of the Candida cell wall may present a prospective target for the development of such a vaccine; however, the radical processing by antigen-presenting cells of the immune system is not fully understood. In this work a set of tailor-made cationic and amphoteric derivatives of three different degrees of quaternization (DSQ 0.14–0.38) has been prepared by chemical modification of ultrasonically-treated mannan and three carboxymethylated mannan derivatives (DSCM 0.13–0.32). These were exposed to free-radical attack by OH, generated in situ by the Fenton reaction. Potential changes in composition, DSQ, and molar mass distribution due to free-radical degradation were monitored by elemental analysis, NMR and FTIR spectroscopies, and size exclusion chromatography. A protective effect of quaternization against OH degradation was found. Non-isothermal thermogravimetric analysis found that the thermal stability of this mannan was also improved by chemical modification.

Biomaterials based on N,N,N-trimethyl chitosan fibers in wound dressing applications

In the present work, N,N,N-trimethyl chitosan (TMC) fibers were synthesized successfully and the resulting quaternized materials were characterized by FTIR. The designed TMC fibers with different degree of quaternization achieved high water absorption capability. In antibacterial activity study, TMC fibers showed high antibacterial activity than chitosan fibers against the gram-negative bacteria Escherichia coli (>63%) and gram-positive bacteria Staphylococcus aureus (>99%). TMC fibers exhibited no obvious cytotoxicity to mouse embryo fibroblast cells with low extraction concentrations (<0.05g/mL). In animal wound healing test, TMC2 fibers could significantly enhance wound re-epithelialization and contraction compared with the control (chitosan fibers). In conclusion, TMC fibers have a potential to be used as wound dressing materials.

Quaternary ammonium functionalized poly(aryl ether sulfone)s as separators for supercapacitors based on activated carbon electrodes

A series of poly(aryl ether sulfone) copolymers containing quaternary ammonium moieties were obtained by polymerization of methylated copolymers, followed by bromination and derivatization with quaternary-ammonium groups. The copolymer membranes exhibited excellent thermal stability and mechanical properties. Symmetric supercapacitor single cells based on activated carbon and quaternary ammonium functionalized poly(aryl ether sulfone) membranes were fabricated into a three-layer structure: activated carbon electrode//quaternary ammonium functionalized poly(aryl ether sulfone) separator//activated carbon electrode and characterized by cyclic voltammetry, galvanostatic charge–discharge and electrochemical impedance spectroscopy in 6M KOH aqueous solution. The coulombic efficiency of the supercapacitor was as high as 95% over 5000cycles. The effect of different degree of quaternization of PAES copolymer separators on thermal and mechanical properties of separators and performance of the symmetric supercapacitor single cells were investigated.

Effect of quaternization degree on physiochemical and biological activities of chitosan from squid pens

Chitosan was prepared by alkaline N-deacetylation of β-chitin from squid pens, and N-(2-hydroxy) propyl-3-trimethyl ammonium chitosan chloride (HTCC) derivatives, with different degrees of quaternization (DQ) ranging from 0.77 to 1.06, were synthesized. It was identified by FT-IR, 1H NMR and XRD analysis. All of the HTCC showed good water solubility in a wide pH range. The moisture absorption and retention abilities of all the HTCC were much better than that of the chitosan. The moisture absorption and retention values of all the HTCC at 43% RH for 24h were above 49% and 92%, respectively. The scavenging ability of HTCC against hydroxyl and ABTS radicals improved with increasing concentration. The effectiveness of HTCC against hydroxyl radicals was lower than that of chitosan. These results indicated that HTCC, which has a much better moisture absorption and retention capacity, may act as a potential moisturizer in vitro.

In vitro and in vivo studies on ocular vitamin A palmitate cationic liposomal in situ gels

N-trimethyl chitosan (TMC) with different degree of quaternization (DQ) as the coating materials, vitamin A palmitate (VAP)-loaded cationic liposomes dispersed in thermo-sensitive in situ gels (ISG) with poloxamer 407 (P407) as the base were prepared in this study. VAP-loaded liposomes (VAPL) were prepared using a film dispersion method followed by TMC-coating with DQ of 20%, 40% and 60% (TMC20, TMC40 and TMC60), respectively, then dispersed in P407 solution to obtain TMC-coated VAPL ISG. The in vitro properties of the system including morphology, size, zeta potential, entrapment efficiency, drug release and ocular retention were investigated. The ocular retention in vivo, eye irritation and pharmacokinetics in aqueous humor of the system were also studied in rabbits. VAPL revealed a spherical surface with mean size below 100 nm and negative zeta potential. After TMC-coating, the morphology and entrapment efficiency showed no significant changes, while the mean size was increased, zeta potential was changed into positive, and drug release was further sustained, and above all was influenced by DQ of TMC. TMC-coated VAPL exhibited little effect on the gelation temperature of P407 solution, and at the P407 concentration of 25% (w/v), TMC-coated VAPL ISG had the gelation temperature closest to the eye surface (34 °C) after diluted by the artificial tears. Compared with uncoated VAPL ISG and the marketed Oculotect gels, TMC-coated VAPL ISG displayed more retarded drug release and gel corrosion with a good linear relationship between them, and the higher DQ was, the slower drug release and gel corrosion. The ocular retention time in vitro and in vivo of TMC-coated VAPL ISG were both notable prolonged with a positive correlation with DQ of TMC. Compared with the marketed gels, TMC60-coated VAPL ISG showed delayed Tmax, improved Cmax and AUC(0–24) in rabbit aqueous humor, suggesting the sustained drug release and better corneal penetration and absorption. The local irritation of TMC-coated VAPL ISG was proved to be negligible. TMC-coated VAPL ISG with the properties of sustained drug release, prolonged ocular retention, improved corneal penetration and promising bio-safety is valuable to be studied further.

Thermoset Magnetic Materials Based on Poly(ionic liquid)s Block Copolymers

A new methodology for the preparation of nanostructured magnetic thermoset materials without any kind of metal oxide or metal magnetic nanoparticles has been proposed. The present study focuses on the nanostructuration of thermoset materials based on poly(ionic liquid)s block copolymer and the subsequent production of magnetic nanostructured thermoset. Judicious selection of block copolymer, such as P2VP-b-PMMA, soluble in epoxy and its subsequent quaternization leads to a phase modification of the system, from totally soluble to a nanostructured system. Different degree of quaternization of the pyridine groups showed the range of quaternization values which allowed the nanostructuration of the thermoset. Magnetic material was obtained by anion exchange of the quaternized poly(ionic liquid) block copolymer without using any kind of metal oxide or metal magnetic nanoparticles. The different materials obtained by quaternization of the block copolymers, the anion exchange of the polymeric ionic liquid and th...

Nasal and rectal delivery of insulin with chitosan and N-trimethyl chitosan chloride

The aim of this study was to evaluate the ability of TMC, with different degrees of quaternization, to increase insulin absorption in vivo following nasal and rectal administration in rats. Two batches of TMC with different degrees of quaternization (TMC-L, 12.3% quaternized and TMC-H, 61.2% quaternized) and chitosan hydrochloride were administered intranasally (0.25 and 0.5% w/v) and rectally (0.5% w/v) with insulin (4 IU/kg body weight), at a pH of 4.40 and 7.40, in rats. Blood samples were taken over a period of 2 h for measurement of blood glucose levels and plasma insulin levels. Local toxicity evaluation was done by histological examination of the nasal and rectal epithelia. At pH 4.40 all these polymers were able to increase nasal and rectal insulin absorption, compared to the control groups. However, at a pH of 7.40, only TMC-H was able to increase the nasal and rectal absorption of insulin. These results relate to the insolubility of chitosan hydrochloride at neutral pH values, while the charge density of TMC-L is still too low for any significant interaction at pH 7.40. Histological evaluation of the nasal and rectal eptihelia shows no changes in the morphology of the cells after exposure to these polymers. Only slight congestion of the nasal submucosa was observed and all these polymers led to a mild increase in mucus secretion at pH 4.40. Highly quaternized TMC proves to be a potent absorption enhancer in vivo, especially at neutral pH values where chitosan salts are ineffective.

Preparation and evaluation of anti-neuroexcitation peptide (ANEP) loaded N-trimethyl chitosan chloride nanoparticles for brain-targeting

Anti-neuroexcitation peptide (ANEP) is a promising candidate for the treatment of neuroexcitation-associated diseases. N-Trimethyl chitosan (TMC) with different degrees of quaternization was synthesized, characterized and evaluated as a brain-targeting delivery vehicle for ANEP. ANEP-loaded TMC nanoparticles were prepared by ionic crosslinking of TMC with tripolyphosphate (TPP). The optimized formulation of nanoparticles consisted of TMC with a degree of quaternization (DQ) of 36.1% and TPP solution with a concentration of 0.6 mg/mL. The mean encapsulation efficiency and loading capacity of the optimum formulation was 80.63% and 185.4 μg/mL, respectively, while the mean particle size, zeta potential, and pH value were 255 nm, 32.0 mV and 6.61, respectively. ANEP was labeled with FITC for in vivo tissue distribution experiments. The results showed that the targetability of ANEP to brain was significantly increased by TMC nanoparticles. Absorptive-mediated transcytosis was believed to be the main pathway for the brain-targeting of FITC–ANEP–TMC/NPs. These findings demonstrate that TMC nanoparticles are potentially useful brain-targeting delivery systems for ANEP.

Equilibrium and Surface Rheology of Monolayers of Insoluble Polycations with Side Chains

We have studied monolayers of poly(n-tetradecyl 4-vinylpyridinium-co-4-vinylpyridine) bromide with different degrees of quaternization at the air-water interface. The isotherms (surface pressure vs area) present several phase transitions: at low monolayer coverage, there is a phase transition over a characteristic area that increases on increasing the quaternization degree. This behavior can be rationalized in terms of a mean-field theory of 2D semiflexible polymeric chains and could be an indication of a disorder-order transition from a 2D isotropic liquid (IL) at low surface concentration to a 2D nematic phase (N) at higher concentrations. Low-frequency oscillatory strain experiments show that at low surface coverage the monolayers exhibit highly nonlinear behavior, even for low strain amplitude, whereas at higher surface coverage the response is linear for strains higher than 20%. In addition, stress relaxation experiments show a minimum in the characteristic times that coincide with the transition area. These unexpected results at low surface coverage might be characteristic of the system or related to the fact that the oscillatory experiments do not strictly correspond to constant surface-coverage conditions. However, they are in agreement with high-frequency viscoelasticity, obtained by surface quasielastic light scattering, that shows that the dilational viscosity is higher at low surface concentration than for concentrations beyond the surface phase transition. At higher coverage, there is a second phase transition, after which the isotherms present hysteresis, which is not observed below. Ellipsometry indicates that, after this transition, the monolayer thicken, which may be related to 3D growth into a multilayer.

Study on the mechanisms of chitosan and its derivatives used as transdermal penetration enhancers

The efficacy of chitosan (CS) and its derivatives used as transdermal penetration enhancers has been confirmed in our previous research. This study investigated the mechanisms of penetration enhancement by CS and its derivatives, i.e., N-trimethyl chitosan (TMC) with different degree of quaternization (DQ) and mono-N-carboxylmethyl chitosan (MCC). After treatment with CS, TMCs or MCC, the secondary structure changes of keratin in stratum corneum (SC) from mice were examined by an Attenuated Total Reflection-Fourier Transform Infrared (ATR-FTIR) combined with the application of the second-order derivative, deconvolution and curve-fitting. The water content in the SC was also studied by ATR-FTIR. HaCaT cell lines were employed as the cell models in the study. HaCaT cells were first treated with blank D-Hanks solution, CS or its derivatives, and were then fluorescent labeled with DiBAC 4 (3). The change of membrane potential was measured by a flow cytometer (FCM). Alternatively, the treated HaCaT cells were labeled with NBD-C 6-HPC and the change of membrane fluidity was examined under a Confocal Laser Scanning Microscope (CLSM). It was found that CS, TMCs and MCC could significantly affect the secondary structure of keratin in SC in different ways. Although the amide II absorption peak of keratin moved to a lower wave number following treatment with CS, TMCs, or MCC, the β-turning structure of keratin was converted to β-sheeting and random coiling after treatment with TMCs and was converted to β-sheeting and α-helix following treatment with MCC and CS. At the same time, CS and its derivatives all could increase the water content of SC, decrease HaCaT cells membrane potentials and enhance HaCaT cells membrane fluidity significantly. The effect of TMCs appeared to be independent of their DQ. The results suggest that the mechanisms of transdermal enhancement of CS, TMCs and MCC are closely related to their effects on the secondary structure of keratin and water content in SC, cell membrane potential and fluidity.

Oral Delivery of Peptide Drugs Using Nanoparticles Self-Assembled by Poly(γ-glutamic acid) and a Chitosan Derivative Functionalized by Trimethylation

In the study, chitosan (CS) was conjugated with trimethyl groups for the synthesis of N-trimethyl chitosan (TMC) polymers with different degrees of quaternization. Nanoparticles (NPs) self-assembled by the synthesized TMC and poly(gamma-glutamic acid) (gamma-PGA, TMC/gamma-PGA NPs) were prepared for oral delivery of insulin. The loading efficiency and loading content of insulin in TMC/gamma-PGA NPs were 73.8 +/- 2.9% and 23.5 +/- 2.1%, respectively. TMC/gamma-PGA NPs had superior stability in a broader pH range to CS/gamma-PGA NPs; the in vitro release profiles of insulin from both test NPs were significantly affected by their stability at distinct pH environments. At pH 7.0, CS/gamma-PGA NPs became disintegrated, resulting in a rapid release of insulin, which failed to provide an adequate retention of loaded insulin, while the cumulative amount of insulin released from TMC/gamma-PGA NPs was significantly reduced. At pH 7.4, TMC/gamma-PGA NPs were significantly swelled and a sustained release profile of insulin was observed. Confocal microscopy confirmed that TMC40/gamma-PGA NPs opened the tight junctions of Caco-2 cells to allow the transport of insulin along the paracellular pathway. Transepithelial-electrical-resistance measurements and transport studies implied that CS/gamma-PGA NPs can be effective as an insulin carrier only in a limited area of the intestinal lumen where the pH values are close to the p K a of CS. In contrast, TMC40/gamma-PGA NPs may be a suitable carrier for transmucosal delivery of insulin within the entire intestinal tract.

Transdermal permeation enhancement of N-trimethyl chitosan for testosterone

The aim of this study was to evaluate the transdermal permeation enhancement of N-trimethyl chitosan (TMC) with different degrees of quaternization (DQ). TMCs with DQ of 40 and 60% (TMC40 and TMC60) were synthesized and characterized by 1H NMR. Testosterone (TS) used as an effective drug, four different gels were prepared without enhancer, with 5% TMC40, 5% TMC60 or 2% Azone, respectively as enhancer. The effect of TMC60 on the stratum corneum was studied by Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy (ATR-FTIR) combined with the technique of deconvolution. The results showed that TMC60 could significantly affect the secondary structure of keratin in stratum corneum. In vitro permeation studies were carried out using Franz-diffusion cells and in vivo studies were performed in rabbits. Both in vitro and in vivo permeation studies suggested the transdermal permeation enhancement of TMCs. Compared to the TS gel without enhancer, TS gels with enhancers all showed significant enhancing effect on transdermal permeation of TS ( P < 0.05). Meanwhile, compared to 2% Azone, 5% TMC60 had a stronger enhancement ( P < 0.05) while 5% TMC40 had a similar effect ( P > 0.05). The results suggested that the enhancement of TMCs increased with the increase of DQ.

N,N,N‐Trimethylchitosan Chloride as a Gene Vector: Synthesis and Application

N,N,N-Trimethylchitosan chloride with different degrees of quaternization has been synthesized and characterized by (1)H NMR spectroscopy. The particle size ranges from 150 to 600 nm, which is dependent on the N/P ratio and is less influenced by the degree of quaternization. The majority of the particles have a spherical morphology. The zeta potential of the particles increases with the N/P ratio and the quaternization degree of TMC. Short-term contact experiments show good biocompatibility of TMC, but long-term contact experiments reveal its high toxicity. This study suggests that TMC is a promising gene carrier, but further modification is still required to improve its cytocompatibility.

Evaluation and modification of N-trimethyl chitosan chloride nanoparticles as protein carriers

N-Trimethyl chitosan chloride (TMC) nanoparticles were prepared by ionic crosslinking of TMC with tripolyphosphate (TPP). Two model proteins with different p I value s, bovine serum albumin (BSA, p I = 4.8) and bovine hemoglobin (BHb, p I = 6.8), were used to investigate the loading and release features of the TMC nanoparticles. TMC samples with different degrees of quaternization were synthesized to evaluate its influence on the physicochemical properties and release profiles of the nanoparticles. Sodium alginate was used to modify the TMC nanoparticles to reduce burst release. The results indicated that the TMC nanoparticles had a high loading efficiency (95%) for BSA but a low one (30%) for BHb. The particle size and zeta potential were significantly affected by the BSA concentration but not by the BHb concentration. Nanoparticles of TMC with a lower degree of quaternization showed an increase in particle size, a decrease in zeta potential and a slower drug-release profile. As for the alginate-modified nanoparticles, a smaller size and lower zeta potential were observed and the burst release of BSA was reduced. These studies demonstrated that TMC nanoparticles are potential protein carriers, and that their physicochemical properties and release profile could be optimized by means of various modifications.

Synthesis of N, N-dimethyl N-ethyl Chitosan as a Carrier for Oral Delivery of Peptide Drugs

N, N-dimethyl N-ethyl chitosan (DMEC), a quanternized derivative of chitosan was synthesized based on a modified two-step method via a 22 factorial design to optimize the preparative conditions. The degree of deacetylation of the starting chitosan was determined by FTIR and NMR methods and was 95%. In the first step of the synthesis, mono-ethyl chitosan was prepared by introducing an ethyl group onto the amine group of chitosan via a Schiff base and in the next step methyl iodide was added to produce DMEC which was water soluble in a pH range of 4-8. The DMEC polymers with different degrees of quaternization were obtained and fully characterized using FTIR and 1H-NMR spectroscopic methods. Based on 1H-NMR calculations, the degree of quaternization was 52% by optimizing the two-step process.