Pendant Chalcone Moieties Research Articles

Synthesis and Characterisation of Photo-Cross-Linkable Liquid Crystalline Poly(n-[n′-flurobenzoylstyryloxy]alkylmethacrylate)s and Their Fluorescence Lifetime Properties

This paper reports a study on photo-cross-linkable polymer containing pendant chalcone moiety exhibiting liquid crystalline as well as fluorescence lifetime properties in detail. The photoresponsive polymers were prepared, and their structure has been characterized by1H-NMR,13C-NMR, and UV-Visible spectroscopy. The photo-cross-linking behavior of polymers has been studied by UV-Visible and fluorescence spectroscopy. UV spectral studies revealed that the polymers follow2π+2πcyclo addition reactions when they undergo photo-cross-linking under the influence of UV-light. Number and weight average molecular weight of the polymers were determined by Gel Permeation Chromatography (GPC) and polydispersity index value near to 1.5. The thermal and thermooxidative stability of the polymers were determined by Thermogravimetric Analysis (TGA). Thermal transitions were studied by DSC, and presence of mesophases was identified at 147 and126∘Cby hot stage polarized light optical microscopy (HPOM). Fluorescence lifetime measurements using the time-correlated single photon counting (TCSPC) method reveal that the average lifetime values decrease from 5.94 ns to 5.32 ns on UV-irradiation were discussed in detail.

Synthesis, Characterization, and Properties of Thermotropic Novel Liquid Crystalline Photosensitive Polymer

Side-chain liquid crystalline photosensitive polymer was synthesized using pendant chalcone moiety. The pendant chalcone moiety was reacted with methylene spacer followed by incorporating methacryloyl chloride which is then reacted with 4-hydroxy phenyl oxycarbonyl acetophenone which is then polymerized using BPO as an initiator. The structures of the synthesized liquid crystalline photosensitive polymer have been confirmed by spectroscopic techniques like IR, 1H and 13C NMR, and UV visible spectrometer. The thermal stability of the polymer was investigated by thermo gravimetric analysis (TGA). The thermal stability of the polymer decreased with increase in flexible methylene chain. The photochemical properties of this polymer were investigated by UV spectroscopy. Crosslinking proceeds via 2π–2π cycloaddition of the –CH=CH– of the chalcone moieties. Liquid crystalline phase was confirmed by the differential scanning calorimetry (DSC) and hot stage optical polarized microscopy (HOPM).

Synthesis and Characterization of Novel Liquid Crystalline Photoactive Polymers with Pendant Chalcone Moiety

The side-chain liquid crystalline polymers containing terminally substituted biphenyl cinnamoyl esters were synthesized and characterized The structures of the synthesized photosensitive liquid crystalline polymers have been characterized by spectral techniques such as IR, 1H NMR and 13C NMR, and UV visible spectrometer. The rates of photocrosslinking behavior and photoconversion of the polymers have been studied by UV visible spectroscopy. The UV study reveals that the polymer follows (2π + 2π) cycloaddition reaction during their photocrosslinking. Polarizing optical microscopic and differential scanning calorimetry (DSC) studies confirm the formation of thermotropic mesophase upon heating. The above polymers exhibit nematic mesophase. The thermogravimetric analysis (TGA) and DSC studies prove that the nature of the terminal substituent has a significant effect on mesophase temperature as well as thermal stability of these liquid crystalline photoactive polymers.

Synthesis and characterization of mono‐ and di‐methoxy substituted acrylate polymers containing photocrosslinkable pendant chalcone moiety

AbstractTwo acrylate monomers – 4‐(2′‐methoxycinnamoyl)phenyl acrylate, and 4‐(2′,5′‐dimethoxycinnamoyl)phenyl acrylate – comprising photocrosslinkable pendant chalcone moiety and a free radical polymerizable group were synthesized. The monomers were polymerized in the presence of ethyl methyl ketone at 70°C using benzoyl peroxide as the initiator. The polymers were characterized by UV, FT‐IR, 1H‐NMR, and 13C‐NMR spectra. The weight and number average molecular weights of the polymers were determined by gel permeation chromatography. The thermal stability of the polymers was studied by TGA under a nitrogen atmosphere. Glass transition temperatures of the polymers were studied by differential scanning calorimetry. The photoreactivity of the polymers was investigated for potential applications as photoresists in solution using various solvents. Copyright © 2008 John Wiley & Sons, Ltd.

Synthesis, characterization and properties of photoresponsive polymers comprising photocrosslinkable pendant chalcone moieties

AbstractNew methacrylate monomers, namely 4‐methacryloyloxyphenyl‐4′‐fluorostyryl ketone and 4‐methacryloyloxyphenyl‐4′‐ethylstyryl ketone comprising a free radical polymerizable group and a photocrosslinkable group, were synthesized by reacting the respective hydroxychalcones with methacryloyl chloride in the presence of triethylamine. The monomers were polymerized in the presence of ethyl methyl ketone (EMK) at 70 °C using benzoyl peroxide as the initiator. The chemical structures were characterized using various spectroscopic techniques: ultraviolet, Fourier transform infrared, 1H NMR and 13C NMR. The thermal stability of the polymers was studied using thermogravimetric analysis in nitrogen atmosphere. Differential scanning calorimetry was used to determine the glass transition temperature of the homopolymers. Photocrosslinking of the synthesized homopolymers was investigated in solution. The two homopolymers were crosslinked within 10–15 min. After crosslinking, the homopolymers were insoluble in the same solvent. Copyright © 2006 Society of Chemical Industry

Studies on copolymers of 3-methacryloyloxystyryl-4′-methylphenyl ketone and methyl methacrylate

Copolymers with various contents of 3-methacryloyloxystyryl-4′-methylphenyl ketone (MSMPK) and methyl methacrylate (MMA) were prepared in methyl ethyl ketone solution using benzoyl peroxide as a free radical initiator at 70 °C. Characterization of the resulting polymers was done by UV, FT-IR, 1H NMR and 13C NMR spectroscopic techniques. The copolymer compositions were determined by 1H NMR analysis. The monomer reactivity ratios were calculated using linearization methods such as Finemann–Ross ( r 1 = 0.9439 and r 2 = 0.3656), Kelen–Tüdös ( r 1 = 0.9726 and r 2 = 0.4172), and extended Kelen–Tüdös ( r 1 = 0.9731 and r 2 = 0.4055) methods as well as by a non-linear error-in-variables model (EVM) method using the computer program RREVM ( r 1 = 0.9043 and r 2 = 0.3901). The molecular weights ( M ¯ w and M ¯ n ) and the polydispersity index of the copolymers were determined by gel permeation chromatography. The thermal stability of the copolymers solution increases with increase in concentration of MSMPK. Glass transition temperatures were determined by differential scanning calorimeter under nitrogen atmosphere. The photoreactivity of the copolymers having pendant chalcone moieties was studied in chloroform.

Studies on photocrosslinkable copolymers of 4-methacryloyloxyphenyl-3′,4′-dimethoxystyryl ketone and methyl methacrylate

Copolymers with various contents of 4-methacryloyloxyphenyl-3′,4′-dimethoxystyryl ketone (MPDSK) and methyl methacrylate (MMA) were prepared in methyl ethyl ketone solution using benzoyl peroxide as a free radical initiator at 70 °C. Characterization of the resulting polymers was done by UV, FT-IR, 1H NMR and 13C NMR spectroscopic techniques. The copolymer compositions were determined by 1H NMR analysis. The monomer reactivity ratios were calculated using linearisation methods such as Finemann–Ross ( r 1 = 0.4283 and r 2 = 0.3050), Kelen–Tudos ( r 1 = 0.4264 and r 2 = 0.2606), and extended Kelen–Tudos ( r 1 = 0.4022 and r 2 = 0.2704) methods as well as by a non-linear error-in-variables model (EVM) method using the computer program RREVM ( r 1 = 0.4066 and r 2 = 0.2802). The molecular weights ( M ¯ w and M ¯ n ) and the polydispersity index of the copolymers were determined by gel permeation chromatography. The thermal stability of the copolymers increases with increase in concentration of MPDSK. Glass transition temperatures were determined by differential scanning calorimeter under nitrogen atmosphere. The photoreactivity of the copolymers having pendant chalcone moieties was studied in chloroform solution.

Copolymers of 4‐(3′,4′‐Dimethoxycinnamoyl)phenyl Acrylate and MMA: Synthesis, Characterization, Photocrosslinking Properties, and Monomer Reactivity Ratios

4‐(3′,4′‐Dimethoxycinnamoyl)phenyl acrylate (DMCPA) containing pendant chalcone moiety was copolymerized with methyl methacrylate (MMA) by radical polymerization in ethyl methyl ketone at 70°C under a nitrogen atmosphere using benzoyl peroxide (BPO) as a free radical initiator. The prepared polymer was characterized by UV, FT‐IR, 1H‐NMR, and 13C‐NMR spectra. The composition of the copolymer was determined using 1H‐NMR analysis. The monomer reactivity ratios of copolymerization were determined using conventional linearization methods such as Fineman–Ross (r 1 = 0.26 and r 2 = 0.61), Kelen–Tudos (r 1 = 0.26 and r 2 = 0.61), and Ext. Kelen–Tudos (r 1 = 0.23 and r 2 = 0.59), and a non‐linear error‐in‐variables model (EVM) method using the computer program RREVM (r 1 = 0.2541 and r 2 = 0.6094). The molecular weights (M w and M n) of the copolymers were determined by gel permeation chromatography. Thermogravimetric analysis of the polymers in air reveals that the stability of the copolymers decreases with an increase in the mole fraction of MMA in the copolymers. The solubility of the polymers was tested in various polar and non‐polar solvents. The glass transition temperature of the copolymers was determined as a function of copolymer composition. The copolymers were sensitive to UV light and became crosslinked after irradiation with 254 nm light.

Synthesis and characterization of new photoresponsive acrylamide polymers having pendant chalcone moieties

New acrylamide monomers, 4-acrylamidophenyl-2′,3′-benzostyryl ketone (APBSK) and 4-acrylamidophenyl-4′- N, N′-dimethylstyryl ketone (APDSK) having a free-radical polymerizable group and a photocrosslinkable functional group, were synthesized by reacting the corresponding aminochalcones with acryloyl chloride in the presence of triethyl amine. The monomers were polymerized in methyl ethyl ketone at 70 °C using benzoyl peroxide as the initiator. The resulting polymers were characterized by UV, IR, 1H NMR and 13C NMR spectroscopy. The polymers were found to be soluble in several polar aprotic solvents and in chlorinated solvents but insoluble in aliphatic and aromatic hydrocarbons and in alcohols. The molecular weight data of the polymers as obtained from gel permeation chromatography suggests a higher tendency for chain termination by dimerization than disproportionation. The glass transition temperature of the polymers was determined by differential scanning calorimetry. Thermogravimetric analysis of the polymers carried out in air reveals that the polymers possess good thermal and thermo-oxidative stability required of a negative photoresist. The photosensitivity of the polymer was investigated in various solvents in the presence and absence of triplet photosensitizers. The effect of the different solvents and concentration on the rate of photocrosslinking of the polymers were also examined for using the polymers as negative photoresist materials.

Studies on photosensitive homopolymer and copolymers having a pendant photocrosslinkable functional group

AbstractThe methacrylate monomer 4‐methyacryloyloxyphenyl‐3′,4′‐dimethoxystyryl ketone (MPDMSK), having a free‐radical polymerizable group and a photocrosslinkable functional group, was synthesized. The homopolymer and copolymers of MPDMSK with glycidyl methacrylate were synthesized by free‐radical solution polymerization. The structures of the newly synthesized monomers, homopolymer, and copolymers were confirmed by different spectroscopic techniques. The average molecular weights of the polymers were determined by gel permeation chromatography. The thermal stability of the polymers was measured by thermogravimetric analysis in air and the glass‐transition temperatures were determined by differential scanning calorimetry under nitrogen atmosphere. The copolymer compositions were determined by 1H‐NMR analysis. The monomer reactivity ratios were determined by the application of conventional linearization methods such as Fineman–Ross, Kelen–Tüdös, and extended Kelen–Tüdös methods. The photoreactivity of both the homopolymer and the copolymers having pendant chalcone moieties was studied in various solvents. The effects of various factors such as solvents, concentrations, copolymer ratios, and photosensitizers on the rate of photocrosslinking of the newly synthesized polymers were investigated and the results were discussed for using the polymers as negative photoresists. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1023–1037, 2002

Synthesis and characterization of photocrosslinkable functional polymer having pendant chalcone moiety

New methacrylate monomer, 4-methacryloyloxyphenyl-3′-methylstyryl ketone (MPMSK) containing pendant chalcone moiety was synthesized by reacting 4-hydroxyphenyl-3′-methylstyryl ketone (HPMSK) with methacryloyl chloride in the presence of triethyl amine. The monomer, MPMSK was polymerized in ethyl methyl ketone solution at 70±1°C at nitrogen atmosphere using benzoyl peroxide as a free radical initiator. The polymer was characterized by UV, FT-IR, 1H-NMR and 13C-NMR spectra. The molecular weights ( M w and M n) of the polymer were determined by gel permeation chromatography. The thermal stability of the polymer was measured by thermogravimetric analysis in air. The glass transition temperature of the polymer was determined by differential scanning calorimetry. The photosensitivity of the polymer was investigated in various solvents in the presence and absence of various triplet sensitizers. The effect of solvent on the rate of photocrosslinking of the polymer was also studied.

Photocrosslinked polymers based on pendant extended chalcone as photoreactive moieties

The photoreactivity of new homo- and co-photosensitive polymers containing pendant chalcone moieties attached through hexamethylene spacer lengths between the photosensitive group and the backbone were studied. The rates of crosslinking of the prepared polymers were investigated under different conditions in solutions such as: backbone structures, copolymerization, different solvents, different concentrations and different temperatures. The structures of the prepared monomer and polymers were confirmed by different spectroscopic methods and elemental microanalysis. The average molecular weights of the polymers were determined by gel permeation chromatography. The thermal stability of the polymers was measured by thermogravimetric analysis under a nitrogen atmosphere.