Search

Alterations of the Hippo-YAP pathway are potential targets for oral squamous cell carcinoma (OSCC) therapy, but heterogeneity in this pathway could be responsible for therapeutic resistance. We analysed the Hippo-YAP signatures in a cohort of characterised keratinocyte cell lines derived from the mouth floor and buccal mucosa from different stages of OSCC tumour progression and focused on the specific role of YAP on invasive and metastatic potential. We confirmed heterogeneity in the Hippo-YAP pathway in OSCC lines, including overexpression of YAP1, WWTR1 (often referred to as TAZ) and the major Hippo signalling components, as well as the variations in the genes encoding the intercellular anchoring junctional proteins, which could potentially regulate the Hippo pathway. Specifically, desmoglein-3 (DSG3) exhibited a unique and mutually exclusive regulation of YAP via YAP phosphorylation during the collective migration of OSCC cells. Mechanistically, such regulation was associated with inhibition of phosphorylation of epidermal growth factor receptor (EGFR) (S695/Y1086) and its downstream effectors heat shock protein beta-1 (Hsp27) (S78/S82) and transcription factor AP-1 (c-Jun) (S63), leading to YAP phosphorylation coupled with its cytoplasmic translocation and inactivation. Additionally, OSCC lines displayed distinct phenotypes of YAP dependency or a mixed YAP and TAZ dependency for cell migration and present distinct patterns in YAP abundance and activity, with the latter being associated with YAP nuclear localisation. In conclusion, this study provides evidence for a newly identified paradigm in the Hippo-YAP pathway and suggests a new regulation mechanism involved in the control of collective migration in OSCC cells.

Inherently conducting polymers (ICP) have attracted the attention of researchers because of their low cost and environmental stability. However, for commercial applications the poor processibility and solubility of ICPs have inhibited their widespread use. To avoid these disadvantages adducts, blends, and composites of conducting polymers have been developed. With a view to enhance the processibility of polyaniline (PANI), this work reports the synthesis of nano PANI polydihydroxydimethylsiloxane (PDMS) adduct and the formulation of its nanocomposite via the dispersion of this nano adduct in butylated melamine formaldehyde (BMF) cured soy alkyd (SA) in different weight loadings (0.25 wt %, 0.5 wt %, 1 wt %). The formation of PANI-PDMS adduct and its dispersion in butylated melamine formaldehyde (BMF) cured soy alkyd (SA) was confirmed by FTIR, UV-visible, 1H-NMR whereas the morphological characterization was done using TEM and X-ray diffraction analyses. The presence of PANI-PDMS in SA-BMF resin was found to significantly enhance the physicochemical, physicomechanical, and thermal properties which could be utilized in the development of corrosion protective paints and coatings. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Ricinus communis (RC) oil-based materials are currently receiving increasing attention because of economic and environmental concerns. In the present work, RC oil—a natural triol has been utilized for the development of an advanced polymeric material—poly(urethane-ricinoleamide) (PUR) through very simple synthesis and curing strategy, omitting derivatization steps or side reactions, chain extenders and crosslinkers. The synthesis of PUR was carried out in two steps. The first step is the introduction of an amide group in the RC oil (89.5% ricinoleic acid) via base catalyzed amidation, which results in N, N-bis (2-hydroxyethyl) ricinoleamide (HERA). The second step is urethanation of HERA by the reaction of toluene-2,4-diisocyanate (TDI) in minimal possible organic solvent by one-shot technique, which results in the formation of polyurethane along with amide linkages. The physico-chemical and spectral studies (FT-IR, 1H-NMR and 13C-NMR techniques) confirm these two reactions and the structure of PUR. The resin was cured at ambient temperature without any cross linker. Solubility of the resin was investigated in different polar and non-polar solvents. Thermo-gravimetric analysis (TGA)/differential thermal analysis (DTA) and Differential Scanning Calorimetry (DSC) were used to determine the thermal stability and curing behavior of PUR. An ambient cured ricinoleamide modified polyurethane resin exhibited thermal resistance up to 200–220 °C.

In recent years, the development of ecofriendly biodegradable packaging materials from natural polymers particularly agricultural products has received increasing attention in an attempt to substitute the existing nonbiodegradable petro-based polymers. The need for new polymeric materials with tailored properties has driven the interest of industry and academia toward polymer blends. Vegetable oils are known to possess varying amounts of triglycerides having different unsaturation in their chains. Blending of commercial polymers with vegetable oil derived polymers is, therefore, expected to show synergetic behavior in terms of compatibility, physical, and mechanical characteristics with the latter. In an attempt to develop a biodegradable packaging material, blends of poly(vinyl alcohol) (PVA) and castor oil epoxy (COE) were synthesized in the weight ratios of 70/30, 60/40, 50/50, 40/60, and 30/70 by a microwave method. The effect of COE component as well as microwave irradiation on the compatibility and microstructural properties of the blends was investigated using spectral, viscometric, thermal, and morphological techniques. We observed tremendous improvement in mechanical properties after microwave irradiation for 120 s in COE/PVA 70/30 blend due to optimum cross-linking through hydrogen bond formation among the blend components. These results were supported by the SEM as well the TEM data. © 2011 Wiley Periodicals, Inc. Adv Polym Techn 30: 96–109, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.20207

Conventional epoxy resin (DGEBA), in varying proportion, was used to modify epoxidized soybean oil (ESO) based systems, crosslinked by phthalic anhydride. The properties of DGEBA modified ESO systems were investigated by dynamic mechanical analysis, impact testing, tensile and flexural testing, scanning electron microscopy, and thermogravimetric analysis. Single loss factor tan δ peak was obtained for all of the modified systems. The results show the improvement in mechanical properties from their high crosslinking densities through the introduction of DGEBA with increase in initial degradation temperature, as obtained from thermogravimetric analysis. Results approaches to an ideal composition which gives the optimum property. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers

The present study reports a novel approach for the rapid intercalation of linseed oil-derived fatty amide (LFA) in organo-montmorillonite (OMMT)-Cloisite® 93A. The intercalation of LFA (0.25, 0.5, and 1 wt %) in Cloisite® 93A was carried by varying the microwave irradiation time from 30 to 90 s. X-ray diffraction studies confirmed that microwave irradiation resulted in higher intercalation in a shorter reaction time. The basal spacings were shifted from 12.34 to 16.45 A on microwave irradiation for 30 s while exfoliation occurred at and beyond 60 s exposure. Controlled morphology of the nanohybrids was confirmed by transmission electron microscopy analysis on microwave irradiation for 30 s. This biomodified Cloisite® 93A could be used for the preparation of polyesters, polyesteramides, and polyurethanes of controlled morphology for various applications in biomedicine. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

A nanostructured iron oxide (NanoFe(3)O(4), particle size ca. 25 nm and roughness ca. 2:1 nm) film deposited onto a hydrolyzed indium-tin-oxide (ITO) coated glass plate has been used to immobilize cholesterol oxidase (ChOx) to fabricate an impedimetric cholesterol sensor. Electrochemical studies reveal that surface charged Fe(3)O(4) nanoparticles provide better conformation for ChOx loading resulting in enhanced electron transfer between ChOx and the electrode. Impedimetric response studies of the ChOx/NanoFe(3)O(4)/ITO bioelectrode exhibit improved linearity (2.5-400 mg/dL), low detection limit (0.25 mg/dL), fast response time (25 s), high sensitivity (86 Omega/mg dL(-1)/cm(-2)) and a low value of the Michaelis-Menten constant (K(m) 0.8 mg/dL) with a regression coefficient of 0.997.

Summary: An attempt has been made to synthesize boron containing poly (urethane-fattyamide) [B-PUPGFA] through the incorporation of boron in the backbone of non drying oil such as Pongamia glabra oil derived poly (urethane-fattyamide). The synthesis route involves 50% reduction in the use of harmful volatile organic contents [VOCs] and was carried out in situ by condensation reaction between N, N′-bis (2-hydroxyethyl) Pongamia glabra fattyamide and boric acid without solvent followed by the addition polymerization with toluene diisocyanate in minimum solvent. Spectral (FTIR, 1H-NMR and 13C-NMR), physico-chemical, physico-mechanical and chemical resistance of B-PUPGFA was carried out by standard laboratory methods. The antibacterial performance of B-PUPGFA was done by agar diffusion method against E. coli and S. aureus. The aforementioned performance of B-PUPGFA was compared with Pongamia glabra oil based virgin poly (urethane-fattyamide) [PUPGFA]. It is observed that the incorporation of boron has a significant influence on the overall performance of B-PUPGFA film, which shows antibacterial activity against E. coli and S. aureus. Therefore, B-PUPGFA serves as novel and promising biomaterial candidate for use as anticorrosive and antibacterial coating material.

Polyol/nanosilica organic-inorganic hybrids (Si/Lpol) were prepared through facile sol-gel chemistry. Tetraethoxyorthosilane (TEOS) and linseed polyol (Lpol) obtained by hydroxylation of linseed oil were used as inorganic and organic precursors, respectively. Si/Lpol was further treated with toluene-2,4-diisocyanate (TDI) to obtain silica embedded polyurethane (Si/LPU). The structure of the organic-inorganic hybrid was confirmed by FTIR, 1 H NMR, and 13 C NMR spectral analysis. The polyol/nanosilica network shows strong interaction with the remnant polyol backbone through hydrogen bonding, which also has bearing on Tg of polymers. Morphological studies of Si/LPU show the formation of uniform, spherical silica nanoparticles of 2-30 nm size embedded in the polymer matrix. Si/LPU was further reinforced with 2 and 5 wt.-% fumed silica (FS-Si/LPUs); their morphology revealed a carpet layer formation on top of Si/LPU. Thermogravimetric analysis showed improved thermal stability of Si/LPU and FS-Si/LPUs. The polymers exhibit mild to moderate antibacterial behavior against E. coli and S. aureus, respectively, and will pave way in plethora of biological and chemical applications as coating materials.

Ethylene diamine polyesteramide (Ed-PEA) was synthesized from N, N-bis (2-hydroxy ethyl) linseed oil fattyamide and ethylene diamine tetra acetic acid through condensation polymerization. It was further treated with toluylene 2,4-diisocyanate (TDI) in different weight percentage to obtain urethane-modified polyesteramide (Ed-UPEA). The structural elucidation of Ed-PEA and Ed-UPEA were carried out by FTIR, 1H-NMR, and 13C-NMR spectroscopic techniques. Thermal studies of these resins were carried by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The coatings of urethane-modified polyesteramide were prepared on mild steel strips and their anticorrosive behavior of in acid, alkali, water, and xylene were investigated. Thermal stability performance suggests that the system could be safely used upto 200°C. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Processibility is one of the important requirements for the commercial utilization of conducting polymers. Studies on composites and blends based on nano polyaniline (PANI) dispersions have become the subject of scientific curiosity with regard to their morphology, stability, and electron transport properties. In general, polymer nanocomposites are made by dispersing inorganic or organic nanoparticles into either a conventional thermoplastic or thermoset polymer. The present study reports the synthesis of nanostructured MO-PANI and castor oil polyurethane (COPU)–based composites. The effect of loading of nanostructured MO-PANI in COPU on the spectral, physicochemical and morphological properties has been analyzed. © 2009 Wiley Periodicals, Inc. Adv Polym Techn 28:26–31, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20143

The aim of this work was to investigate the structures and properties of boron incorporated linseed oil polyols (BPEPs) and their polyurethanes (BPEPUs). Hydroxylation was performed in situ using H2O2 and acetic acid; the syntheses of BPEPs and BPEPUs involves polyesterification and polyaddition reactions following “single-pot, multi-step” reactions strategy. Spectral (IR, 1H-NMR, and 13C-NMR), physicochemical, thermal (TGA, DSC), physico-mechanical analyses and corrosion/chemical resistance performance of aforementioned resins confirmed the incorporation of boron in polyol and polyurethane backbone. BPEPUs followed a clear cut “three step-ambient temperature” curing strategy. They showed very good resistance to 5 wt % HCl, 3.5 wt % NaCl (unaffected for 16 and 14 days, respectively), moderate alkali resistance and moderate to good antibacterial activity against E. coli and S. aureus. Our investigations reveal that (i) the incorporation of boron has significant influence on the structural, physicochemical aspects, physico-mechanical, chemical resistance behavior, and thermal stability of polyurethanes, (ii) boron linkages play dual role, both as cross linker and modifier, and (iii) BPEPUs may serve as efficient corrosion protective material, which may be safely employed upto 230°C. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

Nanotechnology has emerged as a subject of immense academic interest and excitement in the past few decades. The immediate goal of this science aims at the production of high performance nanomaterials. The present study reports comparative investigations on the in situ polymerization of polyaniline (PANI), and its derivatives poly(1-naphthylamine) (PNA) and poly(o-toluidine) (POT) within the camphor sulphonic acid (CSA) modified montmorillonite (MMT) layers. The polymerization as well as intercalation of the conducting polymers was confirmed by FT-IR, UV-visible spectroscopies, and XRD studies, whereas the morphology of the nanocomposites was analyzed by TEM studies. It was found that the PANI derivatives (PNA and POT) revealed higher intercalation as compared with PANI. The morphology of nanocomposites was found to be governed by the type of conducting polymer intercalated. A large variation in the morphology as well as particle size was observed between the nanocomposites of PANI and its derivatives. The conductivity was found to be in the range of 10−3–10−2 S·cm−1. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers

The present study reports the synthesis and characterization of waterborne interpenetrating network (IPN) of epoxy-acrylic-oleic acid (EpAcO) with butylated melamine formaldehyde (BMF). The effect of BMF on the formation of IPN was investigated in terms of physicochemical, spectral, morphological, and thermal analyses. The coating properties of the IPN were investigated for their physicomechanical, corrosion resistance, and antimicrobial activity. The formation of the IPN was confirmed by FTIR and 1H NMR analyses as well as physicochemical properties. The EpAcO-BMF IPN coatings were found to exhibit far superior corrosion resistance performance and good thermal stability when compared with the reported waterborne epoxy acrylic-melamine formaldehyde systems [EpAc-MF]. The preliminary antimicrobial investigations of the IPNs were carried out by agar diffusion method against some bacteria and fungi. The results revealed that antimicrobial activities were enhanced upon the formation of IPN. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Investigations on the synthesis of nanoconducting polymers have gained much popularity during the past few decades. The processibility of the nanostructured conducting polymers is poor, which hinders their commercial application. Considering the drawbacks of nanostructured conducting polymers, this article reports for the first time the synthesis of processible composites of nanostructured poly(1-naphthylamine) (PNA), a polyaniline derivative with poly(vinyl chloride) (PVC). The composites were prepared by loading different weight ratios of PNA (2–10 wt%) in PVC. The composites were characterized by spectral, thermal, morphological, and conductivity studies. The particle size of PNA/PVC composites was confirmed by transmission electron microscopy and was found to be in the range of 5–20 nm. The highest conductivity of 2.5 × 10−2 S/cm was obtained in the composite with 4 wt% loading of PNA. The high conductivity of the composites was correlated to the agglomerate-free uniform dispersion of self-assembled nanofibrillar network of PNA particles in the PVC matrix. The PNA/PVC composites exhibited good mechanical properties, which holds potential for use in semiconductor nanodevices. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers

A novel attempt has been made to develop ambient cured polyamine amide (PAA) resins by the condensation polymerization reaction of oil fatty amide diol (N,N-bis 2-hydroxy ethyl linseed oil fatty amide) (HELA) and o-phenylene diamine, which was further modified by poly(styrene-co-maleic anhydride) (SMA) at different phr (parts per hundred part of resin) to get a series of PAA–SMA resins. The structural elucidation of HELA, PAA and PAA–SMA were carried out by FT-IR, 1H-NMR and 13C-NMR spectroscopic techniques. The physico-chemical and physico-mechanical analyses were carried out by standard laboratory methods. Thermal analyses of these resins were accomplished by thermogravimetric analyses (TGA) and differential scanning calorimetry (DSC) techniques. Coatings of PAA–SMA were prepared on mild steel strips to evaluate their physico-mechanical and chemical/corrosion resistance performance under various corrosive environments. It was found that among the PAA–SMA systems, PAA-35 showed the best physico-mechanical and corrosion resistance performance. Thermal studies reveal that the coatings can be safely used up to 305 °C.

The efficient utilization of inherently conducting polymers in nanotechnological applications faces challenges in processing them into highly ordered structures that yield novel properties. This paper reports a comparative study on the nanocomposites of poly(1-naphthylamine) (PNA), having a fused aromatic ring, and its conductive nanocomposites with polyvinyl alcohol (PVA) and polyvinyl chloride (PVC). The composites were prepared by two different methods: (a) dispersion of PNA in PVA and (b) in situ polymerization of PNA in PVC. These nanocomposites were characterized by UV–visible spectroscopy, TEM, stress, strain, and conductivity measurements. The variation in the nanostructured morphology of PNA particles in PVA as well as PVC matrix in the two cases resulted from the pronounced interaction of PNA with PVA through hydrogen bond, forming a homogeneous matrix that facilitates the formation of a self-assembled network of PNA nanoparticles. In case of PNA/PVC composite, a discrete, agglomerate-free distribution of PNA particles was obtained. The results revealed that an appropriate choice of synthesis conditions offers a possibility to improve not only the processability but also the pattern of distribution as well as the stability of PNA particles. © 2008 Wiley Periodicals, Inc. Adv Polym Techn 27:40–46, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20117

Nanostructured materials have been establishing themselves as modem generation of high performance materials in many areas ranging from automotive engineering to bioengineering owing to a vast array of their unique properties. Improvements in environmental impact can also be achieved utilizing nanostructure particulates in coating and eliminating the requirement of toxic inhibitors such as chromates. The paper reports a comparative study on the corrosion resistance performance of soya oil alkyd containing nanostructured polyaniline (PANI) and poly(1-naphthylamine) (PNA) composite coatings. The corrosion protective performance was evaluated by physico-mechanical properties, corrosion rate, open circuit potential measurements, and SEM studies. The PNA/ alkyd composite coatings were found to show far superior corrosion resistance performance as compared to PANI/alkyd system.

It was for the first time we attempted to develop zinc and cadmium incorporated linseed oil based poly(esteramide-urethane) [Zn/Cd-LPEAUr], and investigated their structure, mechanism, and properties. The resin was synthesized in situ by the reaction of linseed oil derived fatty amide diol [HELA], divalent zinc/cadmium acetate and toluylene-2, 4 (6), diisocyanate [TDI; 2–12 wt %] with minimal solvent. The structural elucidation of Zn/Cd-LPEAUr was carried out by FTIR, 1H-NMR, and 13C-NMR spectral techniques. TGA and DSC techniques were used to measure the thermal stability and curing behavior of these resins, respectively. The physicomechanical and chemical/corrosion resistance properties were investigated by standard laboratory methods. The performance of Zn/Cd-LPEAUr coating was compared with reported oil based polyesteramide. Antibacterial test of the resins were performed by agar diffusion method against E. coli and S. aureus, and compared with those of petroleum-based metal containing polyurethanes. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Studies on composites and blends based on nanostructured polyaniline (PANI) have become the subject of scientific curiosity with regard to their morphology, stability, and electronic properties. Nanocomposites of conducting polymers display improved mechanical, electrical, optical, and catalytic properties owing to their remarkable nanostructure. The present study reports the synthesis of nanostructured PANI and its composites based on soy oil alkyd. The effect of loading of nanostructured PANI on the physiochemical, physicomechanical, morphological, and thermal properties of the composite has been analyzed. POLYM. COMPOS., 2010. © 2008 Society of Plastics Engineers

Modern engineering science and nanotechnology have hastened the development of high performance corrosion-resistant coatings having a broad spectrum of effectivity under a wider range of hostile environments. The formulation of such coating systems is expected to cause a major revolution in the corrosion world. Conducting polymers have recently proved to be an effective alternative to phosphate–chromate pretreatment that is hazardous due to toxic hexavalent chromium. Moreover, improvements in environmental impact can be achieved by utilizing nanostructured particulates in coating and eliminating the requirement of toxic solvents. The paper reports some preliminary investigations on the corrosion resistance performance of nanostructured methyl orange (MO)-doped polyaniline (PANI)/castor oil polyurethane (COPU) composite coatings on mild steel (MS). The nanostructure of the MO-PANI was confirmed by transmission electron microscopy (TEM). The corrosion protective performance was evaluated by physico-mechanical properties, corrosion rate, and open circuit potential measurements. These coatings were found to act as “corrosion sensors” by exhibiting different colors when placed in acid as well as alkaline media. The protective behavior of coatings was attributed to the formation of a passive iron oxide/dopant layer at the metal-coating interface that impedes the penetration of the corrosive ions. Copyright © 2008 John Wiley & Sons, Ltd.

The commercial use of polyaniline has been impeded by its intractable nature and insolubility. The use of substituted polyaniline has been attempted mainly to increase the processibility of polyaniline, but this approach usually results in the lowering of the conductivity. This study reports the synthesis of poly(1-naphthylamine), a fused ring derivative of polyaniline, and its copolymers with aniline and o-toluidine via a chemical polymerization method. Spectral, thermal, morphological, and conductivity studies were carried out to elucidate the influence of the incorporation of aniline and o-toluidine units into poly(1-naphthylamine). © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Some preliminary studies on epoxidation, hydroxylation, acrylation and urethanation of Linum usitatissimum seed oil (LO) and its derivatives have been carried out. Epoxidation and hydroxylation were performed in situ using H 2 O 2 and acetic acid to develop epoxidized oil (LOE) and epoxy polyol (EP). EP was modified with synthetic monomers, viz. acrylonitrile (AN) and methylmethacrylate (MMA), in the presence of benzoyl peroxide in an inert environment to develop acrylic grafted epoxy polyols (AEPs). EP and AEPs were further treated with an isocyanate, resulting in the formation of plain and acrylic grafted epoxy polyurethanes (EPU and AEPUs). The mechanism of the reaction as well as the structural aspects of LO, LOE, EP, AEPs, EPU and AEPUs were investigated by 1 H-NMR and 13 C-NMR spectroscopic techniques, which also confirmed the incorporation of the acrylic monomers - AN and MMA - on the EP backbone Spectral analyses further demonstrated that, depending on its structure (substituent), each acrylic monomer follows a different grafting mechanism. Physico-chemical characterization of AEPs and AEPUs was carried out by standard laboratory methods, and thermal analyses were accomplished by TGA and DSC. Physico-mechanical characterization of AEPUs coatings further showed considerable improvement compared to the pristine (EPU) resin, due to the introduction of stiff acrylic moieties. The aforementioned studies as well as the coating characteristics of AEPU confirmed that AN and MMA have been incorporated in the EP backbone. These systems can be safely employed at up to 210-220 °C.

Novel conducting polymer composites of linseed-oil-based poly(urethane amide) (LPUA) were synthesized using nanostructured poly(1-naphthylamine) (PNA). The combination of the electrically conducting PNA with LPUA was accomplished through different weight percent loadings (0.5–2.5 wt%) of the conducting polymer. The particle size of the nanocomposite was determined using transmission electron microscopy and was found to be in the range 17–27 nm. Intermolecular hydrogen bonding between the two polymers and formation of urea linkages were confirmed by Fourier transform infrared spectroscopy. The electrical conductivity of the nanostructured conducting composites at 2.5 wt% loading was found to be comparable to that reported for polyaniline (PANI)/polyurethane at 30 wt% loading of PANI. This shows the superior properties of PNA and its potential for application in anti-static as well as corrosion-protective coatings. The present method of formulation of composites using an oil-based polymer matrix is useful and economically feasible in the sense that a great variety of oil-based polymer matrices can be used to form composites that are ecologically safe and exhibit properties similar to commercial polymers. Copyright © 2007 Society of Chemical Industry

Linseed oil based polyesteramide was synthesized at lower temperature in the absence of organic solvent through condensation polymerization reaction [Sf-LPEA]. In this reaction N,N-bis(2-hydroxyethyl) linseed oil fatty amide and phthalic anhydride were heated at temperature lower than their onset of melting points and the by-product, such as water was removed by application of vacuum technique. This approach was employed to overcome the use of volatile organic solvents used during processing and application of resin, which are ecologically harmful. The solubility of Sf-LPEA was checked in different polar and nonpolar solvents. The FTIR, 1H NMR, and 13C NMR spectral techniques were used to confirm the structure of Sf-LPEA. The physicochemical, physicomechanical, and chemical resistance properties of the resin were investigated by standard methods. DSC and TGA were used to determine, respectively, the curing behavior and thermal stability of the resin. The comparative study of these properties of Sf-LPEA with reported polyesteramide [LPEA], which are normally synthesized at higher temperature in organic solvent, was done. It was found that Sf-LPEA exhibited improved physicomechanical, chemical resistance properties, and higher thermal stability compared with LPEA, and hence can find application as corrosion protective coating. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1143–1148, 2007

Hybrid materials, which combine properties of organic–inorganic materials, are of profound interest owing to their unexpected synergistically derived properties and are considered as innovative advanced materials promising new applications in many fields such as optics, electronics, ionics and mechanics. Inorganic fillers are added to polymers in order to increase some of the properties of the compounds. These hybrid polymeric materials are replacing the pristine polymers due to their higher strength and stiffness. In the present work, studies concerning the preparation of poly (methylmethacrylate) [PMMA] and the nanocomposites PMMA/SiO2, PMMA/TiO2 are reported. These nanocomposite polymers were synthesized by means of free radical polymerization of methylmethacrylate, further “sol–gel” transformation-based hydrolysis and condensation of corresponding alkoxide was used to prepare the inorganic phase during the polymerization process of MMA. Electrolytes were synthesized based on these nanocomposite polymers and have shown superior properties as compared to conventional polymer electrolytes. The nanocomposites and the nanocomposite polymer electrolytes (NPEs) with different lithium salts were investigated through an array of techniques including FTIR and calorimetry along with the electrochemical and rheological techniques. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Organic protective coatings are widely used in corrosion control. However, environmental stand- ards establish that the volatile organic compounds either must be removed or controlled at the lowest possible lev- els. The carcinogenic environmental impact of volatile or- ganic compounds has led to the substitution of solvent- borne coatings by water-borne coating systems. Among recently developed water-borne coatings, epoxy- and acrylic-based coatings have a special significance over other reported water-borne systems. Keeping in mind, the importance of water-borne coatings in the present work, we report the synthesis of water-borne epoxy-acrylate (EpAc) and melamine-formaldehyde (MF) as well as for- mulation of their anticorrosive coatings. The structural elucidation of MF-cured EpAc was carried out by FTIR, 1 HN MR, and 13 C NMR spectroscopic techniques. The coatings of EpAc-MF were applied on mild steel strips and were evaluated for physicochemical, physicomechan- ical characterization, and the anticorrosive performance under different environmental conditions. The present coating system EpAc coatings exhibited superior perform- ance as compared to the reported water-borne epoxy- acrylate coatings. The presence of melamine-formalde- hyde in the resin increases the scratch hardness, impact resistance, alkali resistance, and thermal stability of these coatings. EpAc-MF-1 was found to cure at ambient tem- perature and exhibit good physicomechanical proper- ties. 2007 Wiley Periodicals, Inc. J Appl Polym Sci 107: 215- 222, 2008

Oil epoxies can be used as plasticizers in the processing of hard polymers. For this purpose dehydrated castor oil epoxy (DCOE), a product from sustainable resource, has been chosen for blending with poly(methyl methacrylate) (PMMA) to investigate the compatibility of this blend pair. Blends of DCOE/PMMA were prepared in the weight ratios 80/20, 60/40, 40/60, and 20/80 through solution method by mixing in dimethylsulphoxide. Free-standing films of the blend were cast and the miscibility of the two components was investigated by viscosity and ultrasonic measurements, which provided valuable information on the degree of compatibility of the pairs of blends in solution. The compatibility was also examined by differential scanning calorimetry and scanning electron microscopy. All the studies revealed that DCOE was immiscible with PMMA. However, the appearance and texture of the films were not found to show any visible change over several months, which indicates stability of this blend system. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3094–3100, 2006

A series of novel metal-chelated epoxy resins have been synthesized by the condensation of epichlorohydrin (1-chloro-2, 3 epoxy propane) with bisphenolic metal chelates in alkaline medium. The bisphenolic chelates were initially prepared by the reaction of 3-formyl-4, 4′-dihydroxy diphenyl methane and diamine (ethylenediamine/o-phenylenediamine) in 1:2 molar ratio and then with Cu(II), Ni(II), and Co(II) acetate. The metal-chelated epoxy resins were characterized by various instrumental techniques, such as elemental analysis, DSC and TGA, electronic, FTIR, 1H-NMR, and 13C-NMR spectra. The physicochemical properties, viz., epoxide equivalent weight (eq/100 g), hydroxyl value (eq/100 g), refractive index, specific gravity, and specific viscosity were measured by standard procedures. The antimicrobial activities of these chelated resins were screened against Escherichia coli, Staphylococcus aureus, Bacillius subtilis (bacteria), and Candida albicans, Mucor species (yeast) by using agar well diffusion method. All the polymeric chelates show promising antimicrobial activities. Among these polymeric chelates (ERPD)-Cu(II) shows better antimicrobial activities, which can be attributed to higher stability constant of Cu(II) chelate than others. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1347–1355, 2006

We studied the reaction between urea and formaldehyde with the purpose of preparing new polychelates of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), and Zn(II) metal ions. These compounds were characterized by elemental analysis, IR spectroscopy, 1H-NMR, electronic spectroscopy, thermogravimetric analysis (TGA), and molar conductance measurements. The percentage of metal in all of the polychelates was found to be consistent with 1:1.5 (metal/ligand) stoichiometry. The thermal behaviors of these coordination polymers were studied by TGA in a nitrogen atmosphere up to 750°C. The TGA results reveal that the complexes had higher thermal-resistance properties compared to the common urea–formaldehyde resin. The molar conductivity and magnetic susceptibility measurements of the synthesized polychelates confirmed the geometry of the complexes. The antibacterial activity of the polychelates was also investigated with agar diffusion methods. The antibacterial activity of these polychelates was found to be reasonably good compared with standard drugs, namely, ciprofloxacin, ampicillin, and kanamycin. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 928–936, 2006

Diglycidyl ether of bisphenol A epoxy (E) was modified with hydroxyl-terminated polydimethylsilox- ane through a ring-opening addition polymerization reac- tion. The structural elucidation of the siloxane-modified ep- oxy resin (ES) was carried out with Fourier transform infra- red, 1 H-NMR, and 13 C-NMR spectroscopy techniques. The physicochemical characterization of the synthesized resin (ES) was performed with standard methods. E and ES were subjected to paint formulation with the help of a rutile (TiO2) pigment. The formulated paint systems were cured at room temperature with 1,6-diaminohexane (AH) and 1,3- diaminopropane (AP), which were used as curatives. The E-AH, E-AP, ES-AH, and ES-AP paint systems were ap- plied to mild steel strips. The physicomechanical and anti- corrosive performance of the coated panels was evaluated with standard methods. The thermal analysis of these E-am- ine and ES-amine systems was carried out via thermogravi- metric analysis. The effects of siloxane incorporation and amine curatives on the coating properties of the paint sys- tems were also investigated. The ES-AP system exhibited good thermal and corrosion stability performance among all the E and ES paint systems. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4981- 4991, 2006

Blending of two polymers in solution is a simple and cost-effective technique to improve upon the physical and mechanical properties of the component polymers through synergism. To obtain maximum synergy in their properties, the component polymers should be miscible with each other on molecular scale. Polymer blends of complex physicomechanical properties are being actively investigated. Poly(methacrylic acid) (PMAA), a commercial polymer, yields transparent, hard, brittle, and water-sensitive films. It has been blended with natural polymers like dextran, collagen, and gelatin to obtain films with improved physical and mechanical characteristics. Polyesteramides, which are easily synthesized from vegetable seeds oil, a sustainable resource, have found application in surface coatings. These oligomeric products do not make free standing films in the ambient condition. The polyesteramides from vegetable seeds oil can be used to obtain blend with PMMA of improved mechanical and water absorption properties. In this study, linseed oil polyesteramide (LOPEA) and dehydrated castor oil polyesteramide (DCPEA), the source oils with different unsaturation in their fatty acid chains, were blended with PMAA through mixing in solution in the ratio DCPEA/LOPEA: PMAA as 80/20, 70/30, 60/40, 50/50, 40/60, 30/70, and 20/80. In the first instance, the miscibility of the two components was investigated in solution by viscosity and ultrasonic measurements and in solid phase through differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). Moisture absorption by the blend was also studied. DCPEA and LOPEA show immiscibility with PMAA in solution phase while LOPEA with more unsaturation in the fatty acid chain of the oil was found more immiscible than DCPEA. DCPEA shows a narrow miscibility window in the solid phase while LOPEA was found immiscible with PMAA in the solid phase too. Uptake of moisture was found to be markedly reduced in the blends of DCPEA/LOPEA with PMAA. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1367–1374, 2007

Advancements in the area of conducting polymers have been towards their application as effective corrosion protective coatings to replace the use of heavy metals as additives in the coatings industries, which are now considered to be an environmental as well as health hazard. With the aim to utilize a sustainable resource based polymer for the development of an anti-corrosive conducting coating material, coconut oil based conducting blend coatings of polyaniline and poly(esteramide urethane) were prepared by loading different ratios (2, 4 and 8 wt%) of polyaniline in poly(esteramide urethane). Then their physico-chemical, thermal, morphological, conductivity and anti-corrosive coating characteristics were investigated. The effect of a 2 year environmental aging process on the coated samples was analyzed by thermal methods as well as by corrosion studies. Results showed that the corrosion protective performance of the blend coatings was far superior than that of plane poly(esteramide urethane). These coatings showed enhanced corrosion protection in acid as well as alkaline environments upto 360 and 192 hr respectively. Conductivity of the blends was found to be in the range 2.5 × 10−5–5.7 × 10−4 S/cm−1. An increase in the thermal stability of the blend coatings and a decrease in their conductivity was noticed in the aged samples which was attributed to the crosslinking effect. The corrosion protective performance of the coatings remained almost unaffected even after 2 years of aging. Copyright © 2005 John Wiley & Sons, Ltd.

With the aim to utilize a vegetable oil epoxy, a product from a sustainable resource, for improving the properties of polymethacrylic acid (PMAA), the blends of the latter with the epoxy of linseed oil were prepared in solution by mechanical mixing of the requisite amounts of the two components in dimethylsulphoxide. Freestanding films of the blend were cast. The miscibility of the two components was investigated by viscosity, ultrasonic, and density measurements which showed that the two components were semicompatible in solution. The compatibility in solid phase was also examined by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM), which revealed that linseed oil epoxy (LOE) and PMAA were incompatible. The films of blend of all compositions were found to be sticky, which was caused by the oozing of LOE. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006

Ambient-cured polyesteramide (APEA) coating resin synthesized from dihydroxy fatty amide obtained from linseed oil, a sustainable resource, and poly(styrene-co-maleic anhydride), a bifunctional acid component, was found to exhibit improved physicomechanical and anticorrosive properties. The structural elucidation of APEA resin has been carried out by FTIR, 1H-NMR, and 13C-NMR spectroscopies. The physicomechanical and chemical resistance properties were investigated by standard methods. The corrosion resistance performance was evaluated in acid, alkali, and organic solvent. The thermal behavior was studied by TGA technique. A comparative study of these properties of APEA with reported baked polyesteramide (PEA) coatings was carried out. A remarkable improvement in the drying property of APEA was observed. The APEA coatings also showed improved physicomechanical and anticorrosive properties as compared to the baked PEA coatings. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1818–1824, 2005

Polyesteramide (PEA) coating resin, synthesized from linseed oil, a sustainable resource, was found to show improved physicomechanical and acid-resistance properties. To further improve these properties in terms of alkali resistance, scratch hardness, and thermal stability and to reduce the baking temperature, we have attempted to incorporate styrene into the polymer backbone through its copolymer with maleic anhydride. The structural elucidation of modified PEA resin (SCPEA) was carried out by FTIR, 1H-NMR, and 13C-NMR spectroscopes. The physicomechanical and chemical-resistance properties were investigated by standard methods and thermal stability was investigated by thermogravimetric analysis method. A comparative study of these properties of PEA and SCPEA was carried out. It was observed that the SCPEA showed better properties than the reported one. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2538–2544, 2004

Blends of poly (methyl methacrylate) (PMMA)/Polypyrrole (PPy) were synthesized by emulsion polymerization of methyl methacrylate (MMA) and in situ oxidative polymerization of pyrrole (Py) with varying concentrations of Py and ferric chloride. The influence of the varying concentrations of ferric chloride, Py, and MMA on the morphological, spectral, thermal, and conductance characteristics of the blends were investigated. Hydrogen bonding between PPy and PMMA was inferred from FTIR studies that indicate blend formation. DSC and TGA analysis of the blends were done. A curious thermal behavior was observed that the blends lost their elasticity and flexibility on heating and turned into rigid and brittle material. DSC thermogram did not show glass transition temperature, indicating molecular and chain reorganization on heating. We have therefore called these blends pseudothermoset. The physicomechanical characteristics of the films of the blends were found to deteriorate with the increased ratio of ferric chloride in the blend, causing a decrease in the conductivity. Maximum conductivity (percolation threshold) was found at 14 wt % loading of Py in the blend (1.6 × 10−3 S cm−1), which was further correlated with the morphology of the films. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 82–91, 2004

Diglycidyl ether of bisphenol A acrylate (DAC) and diglycidyl ether of bisphenol A methacrylate (DMAC) were synthesized by the reaction of an epoxy [diglycidyl ether of bisphenol A (DGEBA)] with acrylic acid and methacrylic acid, respectively. The synthesized resins were characterized by determination of the acid, hydroxyl, and saponification values. Structure elucidation was done by gel permeation chromatography, Fourier transform infrared spectroscopy, 1H-NMR spectroscopy, and 13C-NMR spectroscopy. DACs were cured with melamine formaldehyde resin at low pH values. The pH of the resin systems was adjusted with phosphoric acid. The coatings of these systems were formed on mild steel specimens for physicomechanical and chemical/corrosion-resistance performance. The coatings of DAC and DMAC showed excellent scratch hardness and good impact-resistance performance. The coatings of DMAC showed better performance than DAC with respect to chemical and corrosion resistance. Thermogravimetric analysis and differential scanning calorimetry were used to investigate the thermal stability and curing behavior of these systems. DAC showed a little higher glass-transition temperature than DMAC and also showed a higher thermal resistivity. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 494–501, 2005

Coatings prepared from polyesteramide resin synthesized from linseed oil, a renewable resource, have been found to show improved physicomechanical and anticorrosive characteristics. These properties are further improved when aluminum is incorporated in the polyesteramide resin. The coatings of this resin are generally obtained by baking at elevated temperatures. With a view toward the use of linseed oil, as a precursor for the synthesis of polyesteramide resins and to cure their coatings at ambient temperature, toluylene diisocyanate (TDI) was incorporated into polyesteramide and alumina-filled polyesteramide in varying proportions to obtain urethane-modified resins. The latter resins were found to cure at room temperature. The broad structural features of the urethane-modified polyesteramide and alumina-filled polyesteramide were confirmed by FTIR and 1H–NMR spectroscopies. Scratch hardness; impact resistance; bending resistance; specular gloss; and resistance to acid, alkali, and organic solvents of the coatings of these resins were determined by standard methods. Physicomechanical and anticorrosive properties, specular gloss, and thermal stability of the urethane-modified alumina-filled polyesteramide coatings were found to be at higher levels among these resins. It was found that TDI could be incorporated in polyesteramide up to only 6 wt %, such that above this loading its properties started to deteriorate, whereas alumina-filled polyesteramide could take up to 10 wt % TDI. Explanation is provided for the increase in scratch hardness and impact resistance above 6 and 10 wt % addition of TDI in polyesteramide and alumina-filled polyesteramide, respectively, as well as for the decrease in flexibility and resistance to solvents, acid, and alkali of coatings of these resins above these limits of TDI addition. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1855–1865, 2001

Poly(urethane–fatty amide) (PUPGFA) was developed to use nonedible and nondrying Pongamia glabra seed oil. The resin was synthesized by the reaction of N,N-bis(2-hydroxyethyl) P. glabra fatty amide (HEPGFA) and tolylene-2,4-diisocyanate through a one-shot technique with a minimal amount (8–10%) of organic solvent. The structural elucidation of the resin was carried out by Fourier transform infrared (FTIR), 1H-NMR, and 13C-NMR spectroscopic techniques, whereas the curing mechanism was confirmed by FTIR spectroscopy and differential scanning calorimetry. The solubility of the resin was studied in different polar and nonpolar solvents. Thermal analysis was carried out by thermogravimetric analysis and differential thermal analysis techniques. Antibacterial studies of HEPGFA and PUPGFA were performed in the presence of Gram-negative Salmonella and Gram-positive Staphylococcus aureus bacteria by an agar diffusion method. Physicochemical, physicomechanical, and corrosion-resistance tests were performed by standard laboratory methods. PUPGFA had good physicomechanical properties, excellent chemical/corrosion resistance, and moderate antibacterial activities. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

VLA-4 has been identified as a relatively new target for the development of "non-steroidal" alternatives for the treatment of asthma and related respiratory inflammatory diseases. In continuation of search to identify potent VLA-4 antagonists, a series of novel proline urea derivatives have been synthesized. The newly synthesized compounds are evaluated as potential VLA-4 antagonists in vitro and are found to exhibit moderate VLA-4 inhibitory activity.