Preparation of electrorheological active ionomers from poly(2‐hydroxyethyl methacrylate)‐co‐poly(4‐vinyl pyridine)

In this study, synthesis, characterization, partial hydrolysis, and salt formation of poly(2‐hydroxyethyl methacrylate)‐co‐poly(4‐vinyl pyridine), (poly(HEMA)‐co‐poly‐(4‐VP)) copolymers were investigated. The copolymers were synthesized by free radical polymerization using K₂S₂O₈ as an initiator. By varying the monomer/initiator ratio, chain lengths of the copolymers were changed. The copolymers were characterized by gel permeation chromatography (GPC), viscosity measurements, ¹H and ¹³C NMR and FTIR spectroscopies, elemental analysis, and end group analysis methods. The copolymers were partially hydrolyzed by p‐toluene sulfonic acid monohydrate (PTSA·H₂O) and washed with LiOH_(aq) solution to prepare electrorheological (ER) active ionomers, poly(Li‐HEMA)‐co‐poly(4‐VP). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 99: 3540–3548, 2006     

Preparation and characterizations of superparamagnetic iron oxide‐embedded poly(2‐hydroxyethyl methacrylate) nanocarriers

The present study aims at formulating a novel multifunctional biocompatible superparamagnetic nanoparticles carrier system with homogeneously dispersed magnetic material in solid polymer matrix of poly(2‐hydroxyethyl methacrylate) (PHEMA). The nanocomposites were designed by modified suspension polymerization of 2‐hydroxyethyl methacrylate followed by in situ coprecipitation of iron oxide inside the nanoparticle matrix yielding magnetic PHEMA (mPHEMA) nanocomposites. The so prepared nanocomposites were characterized by Fourier transform Infrared spectroscopy, X‐ray diffraction technique, Raman spectroscopy, electron diffraction, and energy‐dispersive X‐ray spectroscopy confirming the presence of Fe₃O₄ inside the PHEMA nanoparticles. The magnetization studies of nanocomposites conducted at room temperature using vibrating sample magnetometer suggested for their superparamagnetic nature having saturation magnetization (Ms) of 20 emu/g at applied magnetic field of 5 kOe. Transmission electron microscopy, field‐emission scanning electron microscopy, and dynamic light scattering/zeta potential measurements were also performed which revealed that size of mPHEMA nanocomposites was lying in the range of 60–300 nm having zeta potential of ?93 mV. The nanocomposites showed no toxicity as revealed by cytotoxicity test performed on L‐929 fibroblast by extract method. The results indicated that the prepared superparamagnetic mPHEMA nanocomposites have enormous potential to provide a possible option for magnetically assisted targeted delivery of anticancer drugs. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40791.     

Dynamics of blood proteins adsorption onto poly (2‐hydroxyethyl methacrylate)‐silica nanocomposites: Correlation with biocompatibility

A nanocomposite hybrid of poly(2‐hydroxyethyl methacrylate) (PHEMA) and silica (PHEMA‐Si) was prepared by sol–gel process and characterized by FTIR, environmental scanning electron microscopy (ESEM), and XRD techniques. The prepared hybrid was evaluated for its water sorption capacity and the adsorption of blood proteins such as bovine serum albumin (BSA) and fibrinogen (Fgn) was carried out on the hybrid surfaces. The dynamic nature of the adsorption process was investigated and related kinetic parameters were evaluated. The effect of factors like concentrations of protein solutions, pH, and ionic strength of the adsorption medium and chemical architecture of the hybrid were investigated on the adsorption process. The prepared hybrids were also examined for in vitro blood compatibility. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Preparation and characterization of cyhalothrin‐loaded poly(2‐hydroxyethyl methacrylate)‐co‐polylactide (PHEMA‐co‐PLA) ultrafine particles

Poly(2‐hydroxyethyl methacrylate)‐co‐polylactide (PHEMA‐co‐PLA) and its corresponding cyhalothrin‐loaded ultrafine particles were successfully synthesized and prepared, respectively. The chemical structures of the copolymers have been confirmed by Fourier transform infrared spectroscopy (FTIR), ¹H‐nuclear magnetic resonance (¹H‐NMR), ¹³C‐nuclear magnetic resonance (¹³C‐NMR), and thermogravimetric analysis (TGA). Furthermore, the particle size, the cyhalothrin loading content (LC), and the cyhalothrin release behavior were investigated. PHEMA‐co‐PLA proved to be a good material for the preparation of ultrafine particles for lipophilic pesticide delivery. The developed cyhalothrin‐loaded PHEMA‐co‐PLA ultrafine particles showed good dispersity in water and sustained release behavior. In addition, it is easy to be prepared by both nanoprecipitation method and emulsion/solvent evaporation method. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Synthesis and characterization of poly(dimethylamino ethyl methacrylate)–poly(ethylene oxide)–poly(dimethylamino ethyl methacrylate) triblock copolymers

Novel, monodispersed, and well‐defined ABA triblock copolymers [poly(dimethylamino ethyl methacrylate)–poly(ethylene oxide)–poly(dimethylamino ethyl methacrylate)] were synthesized by oxyanionic polymerization with potassium tert‐butanoxide as the initiator. Gel permeation chromatography and ¹H‐NMR analysis showed that the obtained products were the desired copolymers with molecular weights close to calculated values. Because the poly(dimethylamino ethyl methacrylate) block was pH‐ and temperature‐sensitive, the aqueous solution behavior of the polymers was investigated with ¹H‐NMR and dynamic light scattering techniques at different pH values and at different temperatures. The micelle morphology was determined with transmission electron microscopy. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis and characterization of poly(2‐hydroxyethyl methacrylate)‐functionalized Fe‐Au/core‐shell nanoparticles

Disulfide‐bearing poly(2‐hydroxyethyl methacrylate) (DT‐PHEMA) was synthesized by atom transfer radical polymerization technique, which was subsequently immobilized onto core‐shell structured Fe‐Au nanoparticles (Fe‐AuNPs) by applying a “grafting to” protocol to afford new PHEMA‐grafted Fe‐AuNPs (PHEMA‐g‐Fe‐AuNPs). The Fe‐AuNPs having the iron core of 20–22 nm and the gold layer of 1–2 nm were initially prepared by inverse micelle technique and characterized by XRD and high‐resolution transmission electron microscopy (HR‐TEM). The grafting of DT‐PHEMA on the Fe‐AuNPs was confirmed by Fourier transformed infrared spectrophotometer, thermogravimetric (TGA), X‐ray photoelectron spectroscopy, and energy dispersive X‐ray analyses. The average diameter of polymer coated Fe‐AuNPs was determined to be 28 nm by HR‐TEM analysis. The amount of the polymer on the surface of Fe‐AuNPs was calculated to be about 50% by TGA analysis. The studies of magnetic property by the superconducting quantum interference devices indicate the superparamagnetic property of Fe‐AuNPs and PHEMA‐g‐Fe‐AuNPs. The optical property of the PHEMA‐g‐Fe‐AuNPs was recorded by UV–visible absorption spectroscopy, and a redshift in the absorption was observed, which further suggests the PHEMA attachment on the surface of Fe‐AuNPs. The magnetic nanocomposites demonstrate good dispersibility in common polar solvents. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Rheological properties of homogeneous and heterogeneous poly(2‐hydroxyethyl methacrylate) hydrogels

The swelling and rheological behaviour of hydrogels of morphology varying from non‐porous to highly porous was investigated. The hydrogels were prepared by redox free radical copolymerization of 2‐hydroxyethyl methacrylate with 0.1 to 5 mol% of di(ethylene glycol) dimethacrylate in the presence of water varying from 40 to 80 wt%. Various compositions led to clear, turbid or macroporous gels. The morphology of the gels was characterized using optical microscopy and cryoscan electron microscopy. The oscillatory shear and creep of swollen gels revealed that there was a pronounced difference between homogeneous or microheterogeneous and macroporous gels with communicating pores. The achievement of optimum conditions for the correct determination of shear modulus was also analysed. Copyright © 2011 Society of Chemical Industry     

Preparation and characterization of poly(methyl methacrylate)‐intercalated graphite oxide/poly(methyl methacrylate) nanocomposite

A poly(methyl methacrylate)‐intercalated graphite oxide/poly(methyl methacrylate) nanocomposite was prepared by emulsion polymerization of methyl methacrylate in the presence of graphite oxide (GO). GO was synthesized by the oxidization of natural graphite powder with KMnO₄ in concentrated sulfuric acid. The functional groups and microstructure of the oxidized graphite and the composite were carefully characterized by use of X‐ray diffraction, infrared, transmission electron microscopy, and elemental analysis. The electrical conductivity and mechanical properties were also measured. Polym. Eng. Sci. 44:2335–2339, 2004. © 2004 Society of Plastics Engineers.     

Poly(hexylacrylate)Core‐poly(ethyleneglycol methacrylate)Shell nanogels as fillers for poly(2‐hydroxyethyl methacrylate) nanocomposite hydrogels

The preparation of poly(hexylacrylate)_core‐poly(ethyleneglycol methacrylate)_shell (PHA‐co‐PEGMA) nanogels, to be used as fillers in nanocomposite hydrogels, is reported. Stable nanogels with particle sizes between 90–300 nm were obtained varying the conditions of synthesis. The synthesis recipe of the nanogels could be easily scaled up. Purified and dispersed nanogels in aqueous solution were used as soft fillers for poly(2‐hydroxyethyl methacrylate) (PHEMA) hydrogels, crosslinked with ethylene glycol dimethacrylate (EGDMA). The obtained nanocomposite hydrogels exhibit a larger swelling capacity and a higher thermal stability in comparison with the non‐filled PHEMA hydrogels. Young, storage, and lost moduli, increase largely, in the better case up to 72.5% in the swollen state; while in the dry state the storage modulus increase up to 4.7 fold with a very low load on nanogels (0.64 wt%); resulting in biomaterials with improved properties with potential applications in medical devices. POLYM. ENG. SCI., 59:170–181, 2019. © 2018 Society of Plastics Engineers     

Synthesis and characterization of poly[4‐(2‐thiazolylazo)phenyl methacrylate]‐co‐poly(methyl methacrylate)

A new methacrylic monomer, 4‐(2‐thiazolylazo)phenylmethacrylate (TPMA) was synthesized. Copolymerization of the monomer with methyl methacrylate (MMA) was carried out by free radical polymerization in THF solution at 70 ± 0.5°C, using azobisisobutyronitrile (AIBN) as an initiator. The monomer TPMA and the copolymer poly(TPMA‐co‐MMA) were characterized by Fourier transform infrared (FTIR), ¹H nuclear magnetic resonance (NMR), and elemental analysis methods. The polydispersity index of the copolymer was determined using gel permeation chromatography (GPC). Thermogravimetric analysis (TGA) of the copolymer performed in nitrogen revealed that the copolymer was stable to 270°C. The glass transition temperature (T_g) of the copolymer was higher than that of PMMA. The copolymer with a pendent aromatic heterocyclic group can be dissolved in common organic solvents and shows a good film‐forming ability. Both the monomer TPMA and the copolymer poly (TPMA‐co‐MMA) have bright colors: orange and yellow, respectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2152–2157, 2007     

Preparation of poly(butylene succinate)‐poly[2‐(dimethylamino)ethyl methacrylate] copolymers and their applications as carriers for drug delivery

Copolymers of poly[2‐(dimethylamino)ethyl methacrylate]–poly(butylene succinate)–poly[2‐(dimethylamino)ethyl methacrylate] (PDMAEMA–PBS–PDMAEMA, PDBD) were synthesized through a chain‐extension reaction. The thermal properties characterized using differential scanning calorimetry showed that the introduction of PDMAEMA chains slightly decreased the melting temperature of PBS. The water contact angle of PDBD copolymer films with media of various pH decreased with a decrease of pH. This should be ascribed to the conformational transition of PDMAEMA blocks from a compact coil to an expanding shape in accordance with the variation of the pH of the surroundings. The results of dynamic light scattering and scanning electron microscopy revealed that PDBD copolymers could form spherical micelles with small particle size and narrow particle size distribution. Furthermore, drug loading (loading content, ca 10%; encapsulation efficiency, ca 60%) and release experiments were conducted using doxorubicin as a hydrophobic model drug. The results of release experiments of copolymer nanomicelles showed that these micelles had pH‐responsive properties. © 2018 Society of Chemical Industry     

Poly(2‐hydroxyethyl methacrylate) nanocomposites: From a nonionic gel to pH sensitivity

2‐Hydroxyethyl methacrylate (HEMA)‐clay nanocomposites were prepared via in situ free radical polymerization using montmorillonite (MMT) as a crosslinker. The structure and surface morphology of the nanocomposites were characterized by Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction, and scanning electron microscopy. It was found that exfoliated or highly expanded intercalated nanocomposite structure was obtained. The swelling degree was determined in distilled water and various pH buffered solutions. The highest swelling capacity in distilled water was observed for the nanocomposite sample prepared with the MMT amount of 10 % (w). It was seen that the diffusion mechanism was Fickian type in distilled water and also in various pH‐buffered solutions. It is interesting that the swelling degree of nanocomposites in alkaline pH values increased by the increasing of MMT in the polymer structure. This result supports the possibility of future applications of the novel nanocomposite in systems for the controlled released of drugs. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers     

Structure and properties of hybrid poly(2‐hydroxyethyl methacrylate)/SiO2 monoliths

Hybrid poly(2‐hydroxyethyl methacrylate) (PHEMA)/SiO₂ monoliths were synthesized via a sol–gel process of the precursor tetraethyl orthosilicate (TEOS) and the in situ free‐radical polymerization of 2‐hydroxyethyl methacrylate (HEMA). The weight ratio of the starting chemicals, TEOS to HEMA, was varied between 100/0 and 0/100. Structural analysis was performed by IR and NMR. The NMR results indicated that the introduction of PHEMA in the silica networks gave rise to a lower degree of condensation of TEOS. The resulting monoliths showed more than 75% transmittance in the visible region, that is, good transparency. Mechanical properties were studied with an Instron tester, and the monoliths exhibited better compressive strength and modulus than did bulk PHEMA. Surprisingly, thermogravimetric analysis (TGA) data showed greater than 50 wt % solid residue up to 700°C, possibly related to some degree of chemical crosslinking between the polymer and the silica moiety, which would greatly improve the thermal stability of such hybrid monoliths compared with a pure PHEMA. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 3168–3175, 2003     

Preparation and characterization of poly(hydroxybutyrate‐co‐hydroxyvalerate)–organoclay nanocomposites

This study describes the microstructure and thermal and mechanical properties of poly(hydroxybutyrate‐co‐hydroxyvalerate) (PHB/HV)–organoclay nanocomposites prepared by melt intercalation using Cloisite 30B, a monotallow bis‐hydroxyethyl ammonium‐modified montmorillonite clay. X‐ray diffractometry and transmission electron microscopy analyses clearly confirm that an intercalated microstructure is formed and finely distributed in the PHB/HV copolymer matrix because PHB/HV has a strong hydrogen bond interaction with the hydroxyl group in the organic modifier of Cloisite 30B. The nanodispersed organoclay also acts a nucleating agent, increasing the temperature and rate of crystallization of PHB/HV; therefore, the thermal stability and tensile properties of the organoclay‐based nanocomposites are enhanced. These results confirm that the organoclay nanocomposite greatly improves the material properties of PHB/HV. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 525–529, 2003     

Preparation and characterization of 2‐hydroxyethyl methacrylate–chitosan functionalized multiwall carbon nanotubes nanocomposites

Surface of chitosan (CS) functionalized multiwall carbon nanotubes (MWCNTs) was modified by using 2‐hydroxyethyl methacrylate (HEMA) monomers and the composites were synthesized under microwave irradiation. In this approach, multiwalled carbon nanotubes were functionalized with HEMA and CS in two steps. Firstly, CS was grafted onto the surface and side wall of carbon nanotubes by using microwave irradiation. At the second step, HEMA monomers were grafted onto the polymeric matrix surface. The modified surface of CS functionalized multi‐walled carbon nanotube composites are confirmed by Fourier transform infrared spectroscopy. Moreover, Transmission electron microscopic and scanning electron microscopic images show the morphological changes of the carbon nanotubes. Thermal gravimetric analysis shows content of HEMA–CS functionalized MWCNTs in the composites. Dispersibility of pristine MWCNTs was compared with dispersibility of resultant composites in aqueous phase as well. Results show that composites have higher dispersibility in aqueous phase. Considering the biomedical importance of HEMA monomers and CS polymer, in future, these materials are expected to be useful in the pharmaceutical industry as novel biomaterials composites with potential applications in drug delivery. POLYM. COMPOS., 35:495–500, 2014. © 2013 Society of Plastics Engineers     

Preparation of collagen‐immobilized poly(ethylene glycol)/poly(2‐hydroxyethyl methacrylate) interpenetrating network hydrogels for potential application of artificial cornea

To enhance the mechanical strength of poly(ethylene glycol)(PEG) gels and to provide functional groups for surface modification, we prepared interpenetrating (IPN) hydrogels by incorporating poly(2‐hydroxyethyl methacrylate)(PHEMA) inside PEG hydrogels. Formation of IPN hydrogels was confirmed by measuring the weight percent gain of the hydrogels after incorporation of PHEMA, as well as by ATR/FTIR analysis. Synthesis of IPN hydrogels with a high PHEMA content resulted in optically transparent and extensively crosslinked hydrogels with a lower water content and a 6 ～ 8‐fold improvement in mechanical properties than PEG hydrogels. Incorporation of less than 90 wt % PHEMA resulted in opaque hydrogels due to phase separation between water and PHEMA. To overcome the poor cell adhesion properties of the IPN hydrogels, collagen was covalently grafted to the surface of IPN hydrogels via carbamate linkages to hydroxyl groups in PHEMA. Resultant IPN hydrogels were proven to be noncytotoxic and cell adhesion study revealed that collagen immobilization resulted in a significant improvement of cell adhesion and spreading on the IPN hydrogel surfaces. The resultant IPN hydrogels were noncytotoxic, and a cell adhesion study revealed that collagen immobilization improved cell adhesion and spreading on the IPN hydrogel surfaces significantly. These results indicate that PEG/PHEMA IPN hydrogels are highly promising biomaterials that can be used in artificial corneas and a variety of other load‐bearing tissue engineering applications. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

A methodology to analyse and simulate mechanical characteristics of poly(2‐hydroxyethyl methacrylate) hydrogel

In the present work, the mechanical properties of poly(2‐hydroxyethyl methacrylate) (PHEMA) such as ultimate strength, ultimate strain and shear modulus under compression were measured. Mathematical models for hyperelastic materials, which are often used to study rubbers or tyres and include the Mooney–Rivlin and neo‐Hookean models, were also used to theoretically analyse mechanical nonlinear behaviour of the hydrogel. The simulations based on these models were then implemented and validated by analysis with experimental data for comparison. The accuracy of simulations using the two models was subsequently assessed and discussed in order to determine which model is a feasible representation and reflection of the true behaviour of the hydrogel. This study on the mechanical behaviour of PHEMA under compression stress will ultimately serve for optimization of the design and manufacture of multilayer microfluidic devices in terms of the distribution of pressure induced in the packaging process, since the implementation of thin PHEMA hydrogel free‐standing films is required to be incorporated with harder polymeric material components, such as thermoplastics or thermoset microfabricated platforms. © 2012 Society of Chemical Industry     

Mechanical characteristics of poly(2‐hydroxyethyl methacrylate) hydrogels crosslinked with various difunctional compounds

Poly(2‐hydroxyethyl methacrylate) hydrogels were prepared in the presence of 30 wt% water using two series of crosslinking agents including divinylic (ethyleneglycol dimethacrylate, 1,4‐butanediol dimethacrylate, 2,3‐dihydroxybutanediol 1,4‐dimethacrylate) and diallylic (1,5‐hexadiene‐3,4‐diol and 1,5‐hexadiene) compounds, over a concentration range between 0.1 and 5 mol%. The resulting polymers were swollen in water to yield homogeneous transparent hydrogels. These hydrogels were characterised in terms of equilibrium swelling in water, tensile properties and compression stress–strain measurements. The influences of the nature and the concentration of crosslinking agent on the swelling behaviour and the mechanical properties of these hydrogels were investigated. The crosslinking efficiency of two representative agents (ethyleneglycol dimethacrylate and 1,5‐hexadiene‐3,4‐diol) was quantified by compression experiments. A much lower crosslinking efficiency (0.013) was observed for 1,5‐hexadiene‐3,4‐diol than for ethyleneglycol dimethacrylate (0.336). It is suggested that the low crosslinking efficiency of diallylic agents is responsible for a trend in properties different from that displayed by the gels crosslinked with dimethacrylates. A comparison was made to the similar effect observed previously in heterogeneous PHEMA hydrogels. © 2001 Society of Chemical Industry     

DNA adsorption on a poly‐L‐lysine‐immobilized poly(2‐hydroxyethyl methacrylate) membrane

The DNA adsorption properties of poly‐L ‐lysine‐immobilized poly(2‐hydroxyethyl methacrylate) (pHEMA) membrane were investigated. The pHEMA membrane was prepared by UV‐initiated photopolymerization and activated with epichlorohydrin. Poly‐L ‐lysine was then immobilized on the activated pHEMA membrane by covalent bonding, via a direct chemical reaction between the amino group of poly‐L ‐lysine and the epoxy group of pHEMA. The poly‐L ‐lysine content of the membrane was determined as 1537 mg m^?2. The poly‐L ‐lysine‐immobilized membrane was utilized as an adsorbent in DNA adsorption experiments. The maximum adsorption of DNA on the poly‐L ‐lysine‐immobilized pHEMA membrane was observed at 4 °C from phosphate‐buffered salt solution (pH 7.4, 0.1 M; NaCl 0.5 M) containing different amounts of DNA. The non‐specific adsorption of DNA on the plain pHEMA membrane was low (about 263 mg m^?2). Higher DNA adsorption values (up to 5849 mg m^?2) were obtained in which the poly‐L ‐lysine‐immobilized pHEMA membrane was used. Copyright © 2003 Society of Chemical Industry     

Highly photoemissive polymer–transition metal complexes based on poly(2‐hydroxyethyl) methacrylate

The paper presents several new polymer complexes based on poly(2‐hydroxyethyl) methacrylate (P‐HEMA) and transition metals including Y³⁺, Eu³⁺, Tb³⁺ and Dy³⁺. Red‐, green‐, blue‐ and yellow‐emitting polymer complexes with remarkable photoluminescent (PL) properties, high degree of transparency and excellent processability both in bulk and in thin film were prepared and investigated. In the case of the prepared P‐HEMA–Eu³⁺ and P‐HEMA–Tb³⁺ polymer complexes, divinylbenzene was used as a crosslinker resulting a markedly enhanced PL emission, most probably due to the presence of the benzene rings which improve the efficiency of the energy transfer to the cation emissive centres. The prepared polymer complexes were structurally investigated through Fourier transform infrared and X‐ray photoelectron spectroscopies while atomic force microscopy was used to study the morphology of the prepared thin films. Steady‐state fluorescence spectroscopy and absolute PL quantum yield were used for the investigation of the luminescent properties. The impressive PL emission and the convenience of preparation in bulk or thin films could be important arguments for a wide area of applications ranging from photonic conversion materials in optoelectronic devices (light‐emitting diodes, flat‐panel displays) to full‐colour watermarks on special‐purpose papers or PL inks and coatings. © 2019 Society of Chemical Industry