Thermodynamics of alternating copolymer of styrene and CO in the 0—600 K region

The temperature dependence of heat capacity and the temperatures and enthalpies of physical transitions of the alternating copolymer of styrene and CO were studied in the 5—600 K region by the adiabatic vacuum and dynamic calorimetric techniques. The heat of combustion of the copolymer was measured at 298.15 K in a calorimeter with a static bomb and an isothermal shield. The thermodynamic parameters of glass transition and fusion were determined. The thermodynamic functions in the 0—550 K region and thermodynamic characteristics of the formation of the copolymer from simple substances at T = 298.15 K and p = 101.325 kPa were calculated. The thermodynamic parameters of alternating copolymerization in the bulk of styrene and CO were calculated in the 0—350 K region at a standard pressure.     

Thermodynamics of alternating copolymer of ethylene and carbon monoxide in the 0–600 K region

The temperature dependence of the heat capacity of the alternating copolymer (ACP) of carbon monoxide with ethylene was studied, and temperatures and enthalpies of its phase transformations were measured by adiabatic vacuum, dynamic, and isothermal calorimetry in the temperature range from 8 to 600 K. The energy of burning of ACP was measured at 298.15 K in a calorimeter with the static bomb and isothermal shell. The thermodynamic parameters of transformation of the α-form of ACP crystals into the β-form and fusion of the β-form were determined. The thermodynamic functions for the 0–507 K range and thermodynamic characteristics atT=298.15 K andp=101.325 kPa were calculated. The thermodynamic parameters of the alternating copolymerization of ethylene and CO at 0–507 K and standard pressure were calculated for the bulk reaction. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 284–288, February, 1998.     

Copolymerization kinetics of ethylene and carbon monoxide in the presence of palladium complexes

The copolymerization kinetics of ethylene and carbon monoxide has been studied for the catalysts: Pd(C₅H₇O₂)₂-P(C₆H₅)₃-p-CH₃C₆H₄SO₃H in the medium of acetic acid (system A), and Pd(CH₃COO)₂-CF₃COOH - (C₆H₅)₂P(CH₂)_nP(C₆H₅)₂(system B), where n=1−6, in the medium of methyl alcohol. The cationic palladium(II) -diphosphine complexes: (Dppp)₂Pd(CF₃COO)₂ (I) and [(Dppp) Pd(μ-OH)₂Pd(Dppp)] (CF₃COO)₂ (II) have been synthesized and investigated by IR, electrospray mass spectrometry and elemental analysis methods. A comparative study of the copolymerization kinetics in the presence of these complexes and system B has been carried out.     

Sorption of Precious Metals with Carbon Sorbents

Sorption of gold and silver cyanide complexes with carbon sorbents based on composite polymeric materials and its thermodynamic characteristics were studied.     

Thermodynamics of alternating copolymer of propylene and CO in the 0–550 K region

The temperature dependences of the heat capacity and the temperatures and enthalpies of physical transitions of the alternating copolymer of propylene and CO were studied in the 5–550 K region by adiabatic vacuum and dynamic calorimetry techniques. The heat of combustion of the copolymer was measured at 298.15 K in a calorimeter with a static bomb and an isothermal shield. The thermodynamic parameters of glass transition and fusing were estimated. The thermodynamic functions in the 0–450 K region and the thermodynamic characteristics of the formation of the copolymer from simple substances atT=298.15 K andp=101.325 kPa were calculated. The thermodynamic parameters of the alternating copolymerization of bulk propylene and CO were calculated in the 0–450 K region at standard pressure.     

Adhesive properties of gamma-irradiated polyketone

The effect of polyketone (PK) γ-irradiation dose on the energy characteristics of the PK surface, the specific free surface energy, and the interfacial energy at the boundary between polar (water) and nonpolar (octane) liquids has been studied for the first time. The most significant changes in the energy characteristics of the surface occur at doses up to 100 kGy, and improvement in PK adhesion to the polar and nonpolar phases is observed at doses above 75 and 200 kGy, respectively.     

Thermodynamics of the terpolymer of carbon monoxide,ethylene, and 1-butene

The heat capacity and the temperatures and enthalpies of physical transformations of the alternating terpolymer of carbon monoxide, ethylene, and 1-butene (the content of butene units is 10.7 mol.%) were studied by adiabatic and differential scanning calorimetry in the temperature range from 6 to 520 K. The energy of terpolymer combustion was measured at 298.15 K on an calorimeter with an isothermal shell and static bomb. The standard thermodynamic functions C°_p(T), H°(T)–H°(0), S°(T)–S°(0), and G°(T)–H°(0) for the range from Т → 0 to 400 K, the standard enthalpy of combustion, and the thermodynamic parameters of formation of the partially crystalline CO—ethylene—1-butene terpolymer at 298.15 K, as well as the thermodynamic characteristics of its synthesis in the range from T → 0 to 400 K were calculated.     

The effect of γ-irradiation on laser ablation of polyketone

Results of a pioneering study of the effect of laser radiation in vacuum on the surface of a polyketone (alternating terpolymer of ethylene, propylene, and carbon monoxide, POK) plate are presented. It has been found that laser beam irradiation leads to the surface heating of the plate, its melting, and the formation of a characteristic surface microrelief, an ablation crater, from which the gas flow of the ablation plume carries away products that are deposited on surfaces outside the laser beam area to form a coating with a chemical composition close to that of the substrate POK. A rim grows from molten POK around the crater. The melting point of the crystalline modification (377 K), the molecular flow temperature (427 K), and the molecular weight of the coating (25560) are much lower than those of the initial POK (464 K, 477 K, and 159200, respectively), thereby indicating laser-induced chain degradation of POK. The preliminary γ-irradiation of POK to a dose of 100 kGy enhances its laser ablation rate.     

Effect of Gamma-Ray Pre-Irradiation on the Ablation of Polyethylene and Ethylene-Propylene Copolymer Under Continuous CO<Subscript>2</Subscript> Laser Radiation

We report the effect of preliminary γ-irradiation of polyethylene (PE) and ethylene-propylene copolymer (CEP) on the kinetics of polymer ablation under CO₂ laser irradiation. The rate of PE ablation exceeds the rate of CEP ablation at all doses of γ-irradiation. The ablation rate of the polymers can be approximated by a linear function in the initial stage, and the rate reaches a constant value in the second stage of ablation. The rate of laser ablation increases linearly with the dose of preliminary γ-irradiation in both stages of the kinetics. For PE ablation, the duration of the linear increase in rate decreases with increase in preliminary radiolysis dose. The morphology of the crater surface formed during the laser ablation of γ-irradiated polymers is characterized by a more diverse structure.