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Recently, Meng and Mei (J Math Anal Appl, 2018. https://doi.org/10.1016/j.jmaa.2018.10.051) have introduced two Euler difference sequence spaces $$e_0^t(B_\nu ^{(m)})$$ and $$e_c^t(B_\nu ^{(m)})$$ using generalized difference operator $$B_\nu ^{(m)}$$. Some functional properties and Kothe–Toeplitz duals of the proposed spaces have been determined. Also, the fine spectra of the generalized difference operator $$B_\nu ^{(m)}$$ over the sequence space $$\ell _1$$ have been computed following the results of Dutta and Baliarsingh (Appl Math Comput 219:1776–1784, 2012). In fact, the results for the spectra of the said difference operators are new and interesting. Upon further investigations, it has been noticed that these results should be improved and modified. The primary objective of this note is to provide such sorts of substantial modifications on these results.

In the present article, using difference operators, we develop a novel recursion-free algorithm for inverting any arbitrary non-singular matrix of finite order having LU factorization directly. The entire algorithm is based on LU factorization and individual inversions of triangular matrices L and U using difference operators. The pseudo codes for the complete process including decomposition, inversions of L and U has been constructed and also been verified by Mat lab implementation. The theoretical treatment along with appropriateness and computational effectiveness of the new algorithm is provided.

In this research program, chitosan film was prepared by blending chitosan with Cloisite 30 B at different concentrations 0 wt %, 1 wt %, and 2.5 wt %. The blends were characterized by Fourier transmission infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis. From the FTIR spectra the various groups present in chitosan/C 30 B blend were monitored. The homogeneity, morphology, and crystallinity of the blends were ascertained from SEM and XRD data, respectively. The most suitable form of blend was taken and used as a carrier for the controlled release of ofloxacin. The swelling studies have been carried out at different drug loading. Drug release kinetics was analyzed by plotting the cumulative release data versus time by fitting to an exponential equation which indicated the occurrence of non-Fickian type of kinetics. The drug release was investigated at different pH medium and it was found that the drug release depends upon the pH medium as well as the nature of matrix. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

In the present research program, chitosan has been mixed with polycaprolactone (PCL) (80 : 20) for using them for control delivery of doxycycline. Organo- clay, Cloisite 30B of different concentrations 1, 2.5, and 5% has been blended with the composite. Chitosan is a natu- ral biodegradable polymer where as polycaprolactone is a synthetic biopolymer. The blending of the two polymers has been carried out varying the proportion of nanoclay so that the composite can be a better drug carrier. The blends were characterized by Fourier Transmission Infrared Spec- troscopy (FTIR), Scanning Electron Microscopy (SEM), X- ray Diffraction (XRD) analysis. From the FTIR spectra, the various groups present in chitosan and PCL blend were monitored. The homogeneity, morphology, and crystallin- ity of the blends were ascertained from SEM and XRD data, respectively. The swelling studies have been carried out at different drug loading. Swelling study is an impor- tant parameter to predict the diffusion of the drugs from the matrix. The kinetics of the drug delivery system has been systematically studied. Drug release kinetics was an- alyzed by plotting the cumulative release data versus time by fitting to an exponential equation which indicated the non-Fickian type of kinetics. The drug release was investi- gated at different pH medium, and it was found that the drug release depends upon the pH medium as well as the nature of matrix. V C 2010 Wiley Periodicals, Inc. J Appl Polym Sci 118: 3167-3175, 2010

New biobased, eco-friendly nanocomposites were prepared from maleated polycaprolactone/soy protein isolate blend (50/50 wt/wt) with organo-modified clay by melt compounding. The XRD, TEM, tensile, DMTA, and rheological properties of the nanocomposites were investigated. X-ray diffraction and transmission electron microscopy analysis revealed that the intercalated nanocomposite is formed and the silicate layers of the clay are uniformly dispersed at a nanometer scale in the polymer matrix. There is a great enhancement in tensile and dynamic mechanical properties of the nanocomposites. Rheological study revealed that the nanocomposite exhibits strong shear thinning behavior and clay particles form network in the melted state of the composites. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers

Chitin is the second-most natural polysaccharide in the world, next to cellulose. The main sources of chitin are two marine crustaceans, shrimp and crab. Our objective is to appraise the state of art concerning this polysaccharide, as well as one of its most important derivatives known as chitosan. Chitosan is soluble in acidic aquous media and has vast applications in various fields. Here we briefly describe the characterization, chemical modification, de-polymerization and applications of chitin and chitosan. This review emphasizes recent papers on high value adding applications of these materials in gene therapy, drug delivery, wastewater treatment, packaging, etc.

The demand for biodegradable polymers produced from renewable natural resources continues to grow as environmental concerns increase. Biodegradable plastics derived from agricultural feedstock are a new generation of materials capable of reducing the environmental impact in terms of energy consumption and greenhouse effect in specific applications to perform as traditional/ conventional plastics when in use and are completely biodegradable within a composting cycle through the action of living/micro-organisms. The objective of this study is to examine the potentiality and performance pattern of soy protein isolate (SPI) resin, modified with various concentrations of thiosemicarbazide (TSC), as a thermoplastic to substitute some conventional petroleum-based plastics. The spectral, thermal, morphological properties and the biodegradability of the modified resin have been investigated. The spectral studies indicate that TSC is not crosslinked with the protein moiety; rather, it acts as a modifier. Thermogravimetric analysis of the modified material has been followed using a computer analysis method (LOTUS package) developed by us for assigning the degradation mechanism. A number of equations have been used to evaluate the kinetic parameters. The degradation mechanism has been ascertained on the basis of the kinetic parameters. It is expected that, this environment-friendly, fully biodegradable and sustainable TSC-modified SPI green plastic could be commercially used for making molded products.

Soy protein concentrate, a potential alternative of petrochemical polymers, has been crosslinked with furfural at 0.5,1, 2.5, 5, and 7.5% (w/w). The materials were then compression-molded into plastic tensile bars and tested for tensile and yield strength, percentage elongation, and water absorption. The infrared spectra of the crosslinked product have been studied. The degradation pattern of the crosslinked product has been monitored by TGA method. A computerized LOTUS package method developed by us has been used for evaluating the kinetic parameters. The morphology as well as the biodegradability of the crosslinked product has also been investigated. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2590–2596, 2004

Several castor oil-based polyurethanes (PUs) samples were synthesized using various diisocyanates such as hexamethylene diisocyanate (HMDI) with varying NCO/OH ratios. All the PUs were reacted with methacrylamide (MAM) using an ethylene glycol dimethacrylate (EGDM) crosslinker and benzoyl peroxide as an initiator. Thermogravimetric analysis of the polymers was followed using a computer analysis method for assigning the kinetic mechanism. The degradation steps are discussed in the light of kinetic parameters. The scanning electronic microscopy of some of the interpenetrating polymer networks (IPNs) were studied and the morphology was examined. The samples were subjected to wide-angle X-ray diffraction analysis. Ruland and Vonk's method was used to calculate the degree of crystallinity. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1349–1353, 2001

A large number of improved high-temperature stable semi-interpenetrating polymer networks (semi-IPNs) were synthesized by condensing copolymerized resins with castor oil-based polyurethane using ethylene glycol dimethacrylate (EGDM) as a crosslinker. The structures of these semi-IPNs were studied using various characterization techniques such as IR and nuclear magnetic resonance (NMR) spectra, and the thermal behavior of the semi-IPNs was also studied by thermogravimetric analysis (TGA). A plausible degradation mechanism was suggested in our previous communication. © 1998 John Wiley & Sons, Inc. J Appl Polm Sci 70: 837–842, 1998

Polymerization of 4-vinylbenzoic acid in the presence of C60 using free radical initiator resulted in covalent incorporation of C60 in the polymer structure. Incorporation of the C60 moieties in the polymer was established by IR, NMR, and UV−vis spectroscopy. The solution UV−vis spectra of these C60-containing copolymers appear to be dominated by scattering, obscuring specific electronic excitation features associated with the fullerene. UV−vis spectral analysis of filtrate fractions collected using filters of varying pore sizes indicates that polymers form microgels with polydisperse particle sizes (micron to submicron dimensions) in solution that extensively scatter at shorter wavelengths. Differences in the fluorescence properties of the filtered fractions and unfiltered samples were observed. Furthermore, fluorescence emission spectra of a copolymer showed wavelength-dependent behavior. Polyelectrolyte behavior of these copolymers was studied by concentration dependent viscosity changes of the polymer...

—The application of enzymes in organic synthesis has attracted the attention of many research workers in recent years. Specific enzymatic catalysis is expected to synthesize polymers with high selectivity and/or novel structures. Up to now, the enzymatic synthesis of polyphenols, cellulose, lignin, and polypeptides, as well as non-natural polymers, has been successfully achieved. This review discusses the systematic synthesis of polyphenols using horseradish peroxidase-hydrogen peroxide (HRP-H2O2), the ring-opening polymerization of lactones using the enzyme lipase, and the successful synthesis of cellulose using the enzyme cellulase. The polyphenols enzymatically synthesized have been explored as substitutes of phenol-formaldehyde resins to eliminate the pollution caused by formaldehyde in the environment. Due to their unique π-conjugation nature, these polymers have potential applications in nonlinear optics and in the fabrication of light-emitting diodes. The enzymatic polymerizations using lipase have...

Enzymatic polymerization of alkyl phenols derived from a renewable resource, viz., cashew nut shell, has been carried out in a dioxane-water mixture. The reaction and reaction products have been characterized by a number of spectroscopic, microscopic, and thermometric methods. These monomers have also been copolymerized with various substituted phenols. The homopolymers are soluble in organic solvents while the copolymers are crosslinked, with negligible solubility. Enzymatic polymerization in a dioxane-water solvent mixture results in spherical particles in the case of homopolymerization while structures without distinctive morphologies are obtained in the case of copolymerization. The effects of dioxane-water composition and solution pH on the polymerization reaction have also been explored.

A number of polyurethanes were synthesized by reacting castor oil with hexamethylene diisocyanate, varying the NCO/OH ratio. The polyurethanes were reacted with 2-hydroxyethyl methacrylate ( HEMA) to prepare the interpenetrating polymer networks (IPNs) using benzoyl peroxide as the initiator and ethylene glycol dimethacrylate (EGDM) as the crosslinker. The IPNs are partly soluble in some of the solvents and are less resistant to alkali, but more resistant to acid. The solvent absorption is more pronounced in benzene than in toluene. A novel computerized LOTUS package was used to calculate the kinetic parameters. All the IPNs decomposed with 2-4% weight in the temperature range of to 200°C; 10% weight loss occurs at 300°C and 40% weight loss occurs at 400°C. There is a rapid weight loss from 10 to 90% in the temperature range of 400-500°C. From the kinetic data, it is clear that the degradation process of the IPNs is slower in the temperature range 300-400°C and faster in the temperature range of 440-560°C.

A large number of castor oil based polyurethanes were prepared using various diisocyanates such as isophorone diisocyanate varying the NCO/OH ratio. All the polyurethanes were reacted with acrylamide and methacrylamide using ethylene glycol dimethacrylate as crosslinker and benzoyl peroxide as initiator. Thermogravimetric analysis of the polymers were followed using computer analysis method for assigning the kinetic mechanism. The degradation steps have been discussed in the light of kinetic parameters. The SEM of some of the IPNs has been studied and the morphology has been examined. The samples were subjected to wide angle X-ray diffraction analysis. Ruland and Vonk method was used to calculate the degree of crystallinity (Xcr).

4-Acetyl-phenyl acrylate was prepared by reacting 4-hydroxy acetophenone with acryloyl chloride. It was then polymerized using benzoyl peroxide (BPO) as initiator to give the homopolymer. Both the vinylmonomer and its homopolymer were characterized by FTIR spectra. The polyurethane obtained from castor oil and TDI (Toluene-2,4-diisocyanate) with varying NCO/OH ratio was reacted with the new monomer 4-acetyl phenyl acrylate to give a large number of interpenetrating polymer networks (IPNs) using divinyl benzene as cross-linker and BPO as initiator. The thermogravimetric studies of the IPNs have been carried out and the kinetic parameters have been evaluated.

A number of semi-interpenetrating polymer networks (semi-IPNs) were synthesized by reacting polyurethanes (prepared from castor oil and various diisocyanates) and a phenolic resin (prepared from cardanol and furfural). The physico-chemical properties of the semi-IPNs have been investigated. The thermogravimetric analysis of polymers was followed using a computer analysis method for assigning the kinetic mechanism. Various kinetic equations have been used to evaluate the kinetic parameters. The suggested mechanism of degradation of the semi-IPNs is based on the kinetic parameters.

A number of polyurethanes were synthesized by reacting castor oil with isophorone diisocyanate while varying the NCO/OH ratio. All these polyurethanes were reacted with such acrylic monomers as acrylamide and methacrylamide by using ethylene glycol dimethacrylate as a crosslinker and benzoyl peroxide as the initiator. The physicochemical properties of interpenetrating polymer networks (IPNs) are reported. The durability, solvent absorption, outdoor weathering, and aging properties of IPNs have been studied. Thermogravimetric analysis was used to study the thermal behavior of IPNs and the evaluation of kinetic parameters. A number of equations, such as those of Freeman-Anderson, Broido, Piloyan-Novikova, Horowitz-Mitzger, and Coats-Redfern, have been used to determine the kinetic parameters. The degradation mechanism is discussed.

Castor oil was reacted with isophorone diisocyanate varying the isocyanate/hydroxyl ratio to produce a number of polyurethanes (PUs). All the PUs were reacted with acrylamide and methacrylamide using ethylene glycol dimethacrylate as the crosslinker and benzoyl peroxide as the initiator. Thermogravimetric analysis of the polymers was conducted using a computer analysis method for assigning the kinetic mechanism. The degradation steps have been discussed in the light of the kinetic parameters. © 1995 John Wiley & Sons, Inc.

A number of semi-interpenetrating polymer networks (Semi-IPNs) were synthesized by reacting the polyurethane prepared from castor oil and diisocyanates and the resin prepared from cardanol and furfural. The physico-chemical properties of the semi-IPNs have been investigated. The scanning electron microscopy of some of the semi-IPNs have been studied and the morphology has been examined. The samples were subjected to wide angle X-ray diffraction analysis. The degree of crystallinity (Xcr) were computed on the basis of crystal defect concept developed by Roland and Vonk.

A large number of resins have been synthesised by condensing cardanyl acrylate, a derivative of cardanol (a constituent of Cashewnut Shell Liquid) with formaldehyde and substituted aromatic compounds in the presence of acids as catalyst. The resins have been characterized by IR spectra. The thermal behaviour of the resins have also been studied. The kinetic parameters for the degradation of the resins have also been evaluated by using computer analysis, the LOTUS package, method.

A number of resin copolymers were synthesised by condensing 2,4-dinitrophenyl hydrazone of resacetophenone with furfural and substituted hydroxy aromatic compounds in the presence of some acids and bases as catalyst. The physicochemical properties of the resins have been reported. The ion exchange properties have studied by using a batch equilibrium method. The distribution of a number of metal ions between an aqueous solution and the resin have been measured. A wide range of pH and variable ionic strengths have been investigated.

A number of resins were synthesized by reacting cardanol, a byproduct of the cashew industry, with furfural and substituted aromatic compounds in the presence of acid and basic catalysts. The resins were characterized by IR and NMR spectra and shown to be selective ion exchangers for certain metal ions. A batch equilibrium method was used for studying the selectivity of the metal ions. The thermal behavior of the resins was also studied. A plausible degradation mechanism is suggested. © 1994 John Wiley & Sons, Inc.

A large number of copolymers were synthesized by condensing 2,4-dinitrophenyl hydrazone of 4-hydroxy acetophenone (4HA 2,4 DNPH) with substituted benzoic acids/phenols and formaldehyde in the presence of NaOH or HCl as catalyst. The resins were characterized by IR spectra. The decomposition temperature, solubility parameter, and viscositv of the polymers have been determined. The ion-exchange properties have been studied using the batch equilibrium method. The measurement of the distribution of a given metal ion between an aqueous solution and the resins has been performed. The investigation was carried out over a wide range of pH and varying the ionic strength of the medium. © 1992 John Wiley & Sons, Inc.

A variety of crosslinked resin copolymers have been synthesized by condensing o-hydroxy acetophenone with formaldehyde and chloro-substituted benzoic acids and anilines in the presence of acidic and basic catalysts. The physico–chemical properties of the resins are reported. The thermogravimetric analysis method was used to study the thermal behaviour of the resins; the evolution of kinetic parameters and degradation mechanism was also investigated. Resins from chlorobenzoic acids showed clear two-step degradation neglecting moisture loss, whereas those from chloro anilines gave a somewhat continuous sigmoid. The effect of reaction conditions like monomer, molar ratio, and catalyst is also reported. © 1993 John Wiley & Sons, Inc.

A number of resins have been synthesized by reacting orthohydroxy acetophenone-semicarbazone with substituted benzoic acid and formaldehyde in the presence of some acid and basic catalyst. The physicochemical properties of the resins have been reported. The ion exchange properties of the resins have been investigated. Influence of electrolytes on the metal uptake of Cu2+, Ni2+, Zn2+, Mg2+, and Mn2+ has been studied. The distribution of metal ions at different pH has also been reported. © 1992 John Wiley & Sons, Inc.

A number of resin copolymers have been prepared by condensing some substituted acetophenones with chloro-substituted anilines, benzoic acids, and formaldehyde. The reactivity ratios of the monomers have been computed by using the Kelen–Tudos equation. The results have been discussed taking into account the inductive, resonance, and steric effects of the substituents.

A number of resin copolymers have been synthesized by condensing resacetophenone with substituted benzoic acids and furfural in the presence of some base as catalyst. The resins have been characterized by IR spectra of the characteristic groups. The number-average molecular weights of the resins have been determined by the conductance method. The solubility and viscosity behavior of the resins have been determined. Cu2+, Ni2+, Co2+, Mn2+, Zn2+, and Mg2+ chelates have been prepared. The resins were shown to be selective ion exchangers for certain metal ions. The batch equilibrium method was used to study the selectivity of the metal ions. The thermal behavior of the resins has been determined. The values of energy of activation of the degradation of the resins were computed by using the Freeman-Anderson and Broido methods. The biological assays of some of the resins have been evaluated, and some of them were found to be highly sensitive to the bacteria studied.

Although photopolymerization is one of the oldest methods for the initiation of vinyl polymerization, photografting is of recent origin. methods have been used for grafting vinyl monomers onto a large number of fibers by using a multitude of vinyI monomers with a view of improving some of the properties of the fibers to enhance better commercialization. The primary advantage of photoinitiated grafting compared to other methods, such as radiation or chemically initiated During the last three decades, various photoinitiating 91 grafting, is that some of the basic properties of the graft polymer can be imparted to the fiber without affecting its basic structure and morphology.

A number of new resins were synthesized from 2,4-dihydroxyacetophenone and 2,5-dihydroxyacetophenone by reaction with substituted hydroxy, amino, and chloro compounds and formaldehyde in presence of various acids and bases as catalyst. The resins were characterized by IR spectra. The solution and chemical properties of the resins were investigated. The solubility parameter was calculated from Small's and Hoy's group contribution methods. The fungicidal properties of the resins synthesized have been evaluated.

A number of resin copolymers have been synthesized by condensing p-hydroxy phenacyl bromide, substituted benzoic acids, and formaldehyde catalyzed by acids. The resin copolymers were characterized by IR spectra. The solution, thermal and chemical properties of the resins have been investigated. Ion exchange selectivity with respect to Cu 2+ and Co 2+ has been studied at different pH. Bacteriocidal and fungicidal properties of the resins have also been evaluated

Ethyl methacrylate grafted nylon-6 fibers prepared by mutual irradiation technique was characterized to determine the modifications in its properties arising as a result of grafting. Scanning electron microscopy study provides some information about the presence of grafting. Density of fibers were found to increase constantly with percentage graft. Where as alkali solubility, moisture regain decreased with percentage graft thereby decreasing the dyeability of the fiber. However the ethyl methacrylate grafted nylon-6 fiber showed improvements in its thermal properties over the original nylon-6 fiber.

It is found that the resin copolymr prepared from p-hydroxyacetophenone 2,4-dinitrophenyl hydrazone-formaldehyde is the most active of all the resin copolymers investigated, being toxic to Staphylococcus aureus, Staphylococcus citrus, Klebsiela, Escherichia Coli, Pseudomonas Pyocyanus, Streptococcus viridius and Proteus, marked by an obtainable sensitivity pattern at above 10% concentration. Of the copolymers prepared from the substituted hydroxy acetophenone semicarbazones, the resin prepared from o-hydroxyacetophenone-p-chlorobenzoic acid-formaldehyde shows toxicity to S. aureus, S. citrus, E. coli and P. pyocyanus at more than 10% concentration

The graft copolymerization of methyl methacrylate onto natural rubber (NR) was carried out varying the concentration of monomer, initiator, thiourea, and silver nitrate over a wide range. The grafting reaction was temperature-dependent. From the Arrhenius plot, the overall energy of activation was computed. A suitable reaction scheme and rate expression for the rate of polymerization was suggested.

A number of resin copolymers have been prepared by condensation of substituted aromatic compounds with formaldehyde in the presence of different acid catalysts. The resin copolymers were characterized by IR, thermal, X-ray diffraction, and by their reactivity ratios. The resins were found to possess high thermal stability. Activation energies of resin degradation were computed using the Freeman–Anderson method. The antifungal activities of several previously synthesized resins were studied.

Photo-induced graft copolymerization of methyl methacrylate onto cellulose was investigated using peroxydiphosphate ion as the photoinitiator. The percentage graft yield increases with increasing both the monomer and initiator concentration. The reaction was carried out at three different temperatures, and the overall activation energy was computed. The kinetic data and other evidence indicate that the overall polymerization takes place by a radical mechanism. A suitable kinetic scheme has been suggested.

The graft copolymerization of methyl methacrylate onto polyester fibers (PET) was investigated using tetravalent cerium as the initiator. The rate of grafting was found to increase progressively with the initiator and monomer concentrations up to 2.5 × 10−2M and 70.41 × 10−2M, respectively. The reaction was found to be catalysed by acid up to 15.0 × 10−2M. The graft yield increased by increasing temperature. The effect of addition of some solvents and thiourea on the rate of grafting was also investigated. A suitable kinetic scheme has been pictured, and rate equations have been derived.

Graft copolymerization of methyl methacrylate onto wool was investigated in aqueous solution using potassium peroxydiphosphate as initiator. The rate of grafting was determined by varying monomer, peroxydiphosphate ion, temperature, solvent, and nature of wool. The graft yield increases with increase in monomer concentration. The graft yield increases significantly by increasing peroxydiphosphate ion up to 80 × 10−4mole/l.; with further increase of peroxydiphosphate ion the graft yield decreases. The rate of grafting increases with increase in temperature. The effect of acid-and water-soluble solvents on the rate of grafting was investigated and a suitable rate expression has been derived.

Photopolymerization of methyl methacrylate was carried out using peroxydiphosphate as a photoinitiator. The rate Rp of polymerization increases as the initiator mole fraction is increased. The initiator exponent was computed to be 0.5. The rate of polymerization increases with increasing monomer concentration and the monomer exponent was calculated to be 1.5. The reaction was carried out at three different temperatures and the overall activation energy was computed to be 4.7 kcal mol−1. The kinetic data and other evidence indicate that the overall polymerization takes place by a radical mechanism, and rate expressions have been derived. A suitable mechanism has been suggested.

The graft copolymerization of methyl methacrylate onto nylon 6 using metal complexes of Mn3+, Co3+, and Fe3+ as initiators was studied. The rate of polymerization, Rp, increased with increasing complex concentrations in the initial stages; but it decreased upon further increase of complex concentrations. With increasing monomer concentrations, the rate of polymerization increased progressively. The graft yield increased with increaing temperature within the range 60–75°C. A suitable kinetic scheme is presented and rate equations are derived.

Photoinduced graft copolymerization of methyl methacrylate onto nylon 6 was investigated by using pyridine–bromine (Py–Br2) charge–transfer complex as initiator. The graft yield increased with increasing monomer and initiator concentration at the initial stages, and therefore it decreased. The initiator exponent was computed to be 0.5. The reaction was carried out at three different temperatures, and the overall activation energy was computed. A suitable mechanism has been suggested.