Kadir Demirelli

A detailed study of thermal degradation of poly(2-hydroxyethyl methacrylate)

The thermal degradation behaviour of poly-2-hydroxyethyl methachrylate and of its deuterium derivative have been studied using thermogravimetry under nitrogen atmosphere, with programmed heating at 10°C/min. At first, the partially degraded polymer has been examined by IR. The cold ring fraction (CRF) was trapped at two ranges from ambient temperature to 340°C and 340–400°C. These CRFs were characterized by IR, 1H, 13C NMR, and GC–MS. When the polymer decomposes thermally at two temperature ranges which are from ambient temperature to 340°C and 340–400°C, at both CRFs, the major product is monomer due to depolymerisation reaction. The side products arising from ester decomposition are a six-membered glutaric anhydride type of ring, an oxolane type of ring, 2-isopropenyl ethyl methacrylate, methacrylic acid and CO2. A mechanism which accounts for all these products has been formulated. The activation energy for the thermal degradation of poly(HEMA) is predicted as 129.8 kJ/mol

3, 4-Dichlorobenzyl methacrylate and ethyl methacrylate system: monomer reactivity ratios and determination of thermodynamic properties at infinite dilution by using inverse gas chromatography

Abstract Copolymers with various contents of 3,4-dichlorobenzyl methacrylate (BzMA) and ethyl methacrylate (EMA) were prepared in 1,4-dioxane solution using 2,2′-azobisisobutyronitrile (AIBN) as initiator at 60°C. The copolymer compositions were determined by 1H NMR analysis. The monomer reactivity ratios were calculated by both Fineman–Ross, and Kelen–Tudos methods. The monomer reactivity ratios were found to be rBMA=0.521±0.019, rEMA=0.847±0.221 (Kelen–Tudos) and rBMA=0.677±0.008, rEMA=1.117±0.209 (Fineman–Ross). The FT-IR, 13C NMR spectra of the copolymers have been discussed. In all other samples thermal degradation proceeded in a single step. A slight increase in thermal stability of the copolymers was observed with increase in BzMA content. Some thermodynamic quantities such as the specific retention volumes, Vg0, weight fraction activity coefficients of solute probes at infinite dilution, Ω 1 ∞ , Flory–Huggins intereaction parameters, χ12∞, between polymers and solvents, the partial molar free energy, ΔG1∞ the partial molar heat of mixing, ΔH1∞, at infinite dilution were determined from the interactions of poly(BzMA-co-EMA) with alcohols, ketones, acetates, aromatics and n-alkanes by inverse gas chromatography method at 130–150°C. All probes are non-solvent for poly(BzMA-co-EMA) (7:93%) and poly(BzMA-co-EMA) (87:13%) at 130–150°C.

Thermal degradation of poly [2-(3-chloro-3-methylcyclobutyl)-2-hydroxyethyl methacrylate]

Abstract The thermal degradation of poly[2-(3-chloro-3-methylcyclobutyl)-2-hydroxyethyl methacrylate] [poly(CBHEMA)] has been studied by using thermal volatilisation analysis (TVA) and thermogravimetry (TG). Programmed heating was carried out at 10 °C min −1 from room temperature to 500 °C. Volatile products were separated by subambient TVA and identified by gasphase IR and MS, and GC-MS for volatile liquids. The cold ring fraction and partially degraded polymer have been examined by IR spectroscopy. The monomer was not formed during the degradation since HCl elimination from the chain began at about 150 °C, which is a low temperature for the production of monomer. However, some monomer homologues from the HCl-eliminated polymer were dedected as minor products. The polymer yields carbon monoxide, methane and oxygen as non-condensable products at − 196 °C. Carbon dioxide, hydrogen chloride, water and some unsaturated and saturated hydrocarbons were found in the volatile products. The liquid products of the degradation, the formation of anhydride ring structures and the mechanism of degradation are discussed.

Synthesis and characterization of two new cyclobutyl and aryl hydroxyethyl methacrylate monomers and their polymers

Two new hydroxyethyl methacrylates having aryl and cyclobutane rings were synthesized by addition to 1-(epoxyethyl)-3-aryl-3-methylcyclobutane to methacrylic acid. The monomers prepared are 2-(3-methyl-3-phenylcyclobutyl)-2-hydroxyethyl methacrylate (PCHEMA) and 2-(3-methyl-3-mesitylcyclobutyl)-2-hydroxyethyl methacrylate (MCHEMA). Both monomers were polymerized at 60°C in 1,4-dioxane solution using benzoyl peroxide as initiator. Poly(PCHEMA) and poly(MCHEMA) and their monomers were characterized by FT-IR and 1H- and 13C-NMR techniques. Weight average molecular weights of the polymers were determined for poly(PCHEMA) poly(MCHEMA) by gel permation chromatography. Thermal stabilities of the polymers were essentially the same. Glass transition temperatures for poly(PCHEMA) and poly(MCHEMA) were determined as 105 and 137°C, respectively. No changes of the polymers by irradiation with UV light at 254 nm were observed.

Preparation and thermal degradation of poly(p-substituted phenacyl methacrylates)

Abstract The preparation and thermal degradation of two poly(p-substituted phenacyl methacrylates), poly(p-bromophenacyl methacrylate) [poly(BPMA)] and poly(p-methoxyphenacyl methacrylate [poly(MPMA)], are described. The monomers produced from the reaction of corresponding phenacylchlorides with sodium methacrylate, were polymerized with AIBN as initiator. The monomers and their polymers were characterized by IR, 1H and 13C NMR. Thermal degradation of the polymers has been studied using a system consisting of a degradation tube, with a condenser for product collection, a gas phase IR cell and a rotary pump, and by thermogravimetry (TG). Product studies were performed by IR, GC–MS, 1H and 13C NMR. Thermal degradations of these two poly(p-substituted phenacylmethacrylates) to give volatile products, begin at about 250°C. The degradation produces anhydride ring structures in the chain at about 260°C. A mechanism of degradation showing the formation of some products is discussed.

Thermal degradation of poly[3-(1-cyclohexyl) azetidinyl methacrylate]

Thermal degradation of poly[3-(1-cyclohexyl)azetidinyl methacrylate] has been studied using a system consisting of a degradation tube, with a condenser for product collection of a gas phase IR cell and a rotary pump, and thermogravimetry (TG). Product analyses were performed by IR, GC–MS, 1H NMR and 13C NMR. Thermal degradation of the polymer begins at low temperature (about 180°C) by decomposition of azetidinyl ring, producing some amine based products. The degradation produces anhydride ring structures in the chain above about 300°C as a result of a reaction between two neighboring units. A mechanism of degradation showing the formation of some products is discussed.

Synthesis, characterization and thermal degradation of poly[(2-phenyl-1,3-dioxolane-4-yl)methyl methacrylate]

Abstract (2-Phenyl-1,3-dioxolane-4-yl)methyl methacrylate prepared from glycidyl methacrylate and benzaldehyde has been polymerized by benzoyl peroxide. Spectroscopic characterization of the monomer and the polymer has been done by means of Fourier transform infra-red (FTIR) and 1H and 13C nuclear magnetic resonance (NMR) spectroscopies. Also, the techniques of gel permeation chromatography and differential scanning calorimetry have been used in the polymer characterization. Thermal degradation of poly[2-phenyl-1,3-dioxolane-4-yl)methyl methacrylate] has been studied by thermogravimetric analysis and FTIR. Volatile products of the degradation have been investigated by FTIR, 1H and 13C-NMR and gas chromatography-mass spectrometry techniques. The degradation to 270 °C of this polymer gives only the monomer. Side-chain decompositions mainly occur in degradation above 270 °C, including decomposition of the 1,3-dioxolane ring. Total degradation to 500 °C produces many volatile product such as the monomer, benzaldehyde, acrolein, acetone, 2-phenyl-4-hydroxymethyl-1, 3-dioxolane, 4-methylene-2-phenyl-1,3-dioxolane, propene, carbon dioxide and others. A mechanism of degradation showing the formation of some of these products is discussed.

Copolymerization and monomer reactivity ratios of 2-(3-mesityl-3-methylcyclobutyl)-2-hydroxyethyl methacrylate with acrylonitrile

Abstract The free radical copolymerization of 2-3-(mesityl-3-methylcyclobutyl)-2-hydroxyethyl methacrylate (MCHEMA) with acrylonitrile (AN) has been carried out in 1,4-dioxane at 60°C. The copolymers were characterized by infrared, 13C and 1H NMR spectroscopic methods. The copolymer compositions were established by elemental analysis. The reactivity ratios of copolymerization were computed by using the Fineman–Ross and Kelen–Tudős methods, and were found to be r1=0.29±0.002, r2=0.98±0.003 and r1=0.21±0.009, r2=0.75±0.003, respectively (r2 is reactivity ratios of MCHEMA). The glass transition temperature and thermal decomposition temperature were investigated by DSC-50 and TGA-50 thermobalance, respectively. The solubility parameters and densities of all the copolymers were determined.

Thermal Degradation and Synthesis of Block Copolymers of Styrene and n-Butyl Methacrylate by Atom Transfer Radical Polymerization

Abstract Poly(n-butyl methacrylate) (PnBMA)-b-polystyrene (PS) (diblock), PnBMA-b-PS, and PnBMA-b-PS-b-PnBMA (triblock copolymers) were synthesized by atom transfer radical polymerization (ATRP), using PnBMA and PnBMA-b-PS with C-Br-end-group as macroinitiators. The diblock and triblock copolymers were characterized by 1H-NMR, FT-IR spectroscopy, and differential scanning calorimetry (DSC). The molecular weight and molecular weight distributions were obtained by gel permeation chromatography (GPC). Polymerization was controlled up to a molecular weight of 46,200, and the polydispersity index was 1.33. The experimental results showed that the polymerization was controlled/living. The thermal degradation behavior of the block copolymers was studied using thermogravimetry (TG) and a single line vacuum system consisting of a degradation tube with a condenser for product collection and a liquid nitrogen trap (−196°C). The block copolymers were heated from ambient temperature to 500°C. The products of degradation were collected at two different fractions, which are cold ring fraction (CRF) and volatile liquid fraction (VLF) trapped at −196°C. All the fractions of diblock and triblock copolymers were investigated by means of IR, 1H-NMR, and GC-MS. In this study, n-butyl methacrylate and styrene are given as major products of degradation. On the other hand, the most important minor products are benzene, ethyl benzene, ethyl methacrylate, and toluene.

Study of Some Thermodynamic Properties of Poly (3,4-dichloro benzyl methacrylate-co-ethyl methacrylate) Using Inverse Gas Chromatography

Thermodynamic quantities were obtained for the interactions of poly (3,4-di-chloro benzyl methacrylate-co-ethyl methacrylate) poly (BMA-co- EMA) with alcohols, ketones, acetates, aromatics and alkanes by the inverse gas chromatography method at different temperatures. The specific retention volumes, V g ○, the sorption enthalpy, ΔH 1 s , sorption free energy, ΔG 1 s , sorption entropy, ΔS 1 s , weight fraction activity coefficients of solute specimens at infinite dilution, Ω 1 ∞, Flory-Huggins interaction parameters, X∞ 12 , between the polymers and solvents were deteniiined. The partial molar free energy, ΔG 1 ∞, the partial molar heat of mixing at infinite dilution and the solubility parameters of the polymer, δ 2 , were calculated at different temperatures. The glass transition temperatures, T g , of poly (BMA-co-EMA) (18:82,%), poly (BMA-co-EMA) (30:70,%), poly (BMA-co-EMA) (40:60,%) and poly (BMA-co-EMA) (73:27,%) were found to be about 58°C, 59°C, 61°C and 63°C, respectively, as determined by differential scanning calorimetry (DSC). Alcohols, ketones, acetates, n-alkanes and aromatics were found to be nonsolvents for poly (BMA-co-EMA) at this temperatures. Also the solubility parameters for poly (BMA-co-EMA) (18:82,%) and poly (BMA-co-EMA) (40:60,%) at infinite dilution were also found by plotting the graph of [(δ 1 2 /RT)-X∞ 12 /V 1 ] versus solubility parameters, δ 1 , of these specimens.