A procedure is described of grafting the acrylic acid onto an oxygen/ozone-activated metallocene ... more A procedure is described of grafting the acrylic acid onto an oxygen/ozone-activated metallocene poly(ethylene-co-propylene). Consequently, the grafted copolymer is applied as a component in a metallocene polyolefin-based hot-melt adhesive composition with increased adhesion. The surface properties and adhesion strength of the prepared hot-melt adhesive (HMA) were determined and used to account for the effect of grafting. The application of grafted polyolefin as one of the components of the HMA mixture provides significant increase in adhesive strength, and it also results in increased compatibility and negligible effects on the technological parameters of the final composition. The obtained results may have significant impact for the practical application of prepared HMA for book bonding.
of plasticized poly(lactic acid)/ poly(3-hydroxybutyrate)/carbon black mulching films during one ... more of plasticized poly(lactic acid)/ poly(3-hydroxybutyrate)/carbon black mulching films during one season of sweet pepper production, European
Crosslinking of polypropylene at 10-220 ~ was investigated. The process was initiated by radicals... more Crosslinking of polypropylene at 10-220 ~ was investigated. The process was initiated by radicals formed either by thermal or by u.v. decomposition of dicumyl peroxide. It was found that fragmentation of macroradicals is the most important reaction during thermal initiation and the crosslinking efficiency increases with decreasing temperature. For u.v. initiation, several chemical and physical factors are important; the efficiency is highest at 65 80'.
The thermal lag associated with the temperature ramping experiment in a dynamic mechanical analys... more The thermal lag associated with the temperature ramping experiment in a dynamic mechanical analysis is demonstrated on carbon black filled vulcanised rubber samples by using a DMTA MkIII from Rheometric Scientific. The importance of achieving thermal equilibrium on the sample before starting the measurement is emphasised. By running a combination of isothermal and ramping steps, the impact of thermal lag on the obtained dynamic mechanical properties can be estimated. For the measurement in tensile mode at a rate of heating of 2°C/min and vertical orientation of the driveshaft motion, the isothermal step applied at the sample glass transition temperature revealed that the temperature equilibration of the sample takes at least 15 min. Consequently, the storage modulus measured during the heating step is overestimated by around two times and the glass transition temperature is shifted to higher values. For the given chamber geometry, the bending mode of measurement exhibits a lower thermal lag than the tensile one. The experimental data indicate that the major factors responsible for thermal lag are heat transfer from the sample environment to the sample surface (which is given by the chamber design), sample position in the chamber and the mutual position of the sample and thermometer Pt-100. Based on the results presented, a recommendation for selecting the experimental conditions is given in order to recognise and minimise the effect of thermal lag on the data obtained by dynamic mechanical analysis.
The 1H–13C cross polarization nuclear magnetic resonance technique was used for the study of mole... more The 1H–13C cross polarization nuclear magnetic resonance technique was used for the study of molecular mobility in amorphous polylactic acid. The cross polarization buildup curves for methine and methyl functional groups measured at magic angle spinning rates of 4 and 10 kHz, under Hartmann–Hahn conditions determined from corresponding Hartmann–Hahn matching profiles, confirmed the presence of 1H–13C spin pairs isolated from lattice since transient oscillations were observed in the initial stages of buildup curves. The values of dipolar coupling constants derived from Fourier transforms of cross polarization buildup curves indicate the presence of rigid methine groups and two kinds of methyl functional groups which differ in mobility. This could be due to the presence of amorphous phase with chain aggregations and phase with less spatial restrictions in this material. Fitting of theoretical expressions to experimental data provided additional information on the cross polarization process in this material.
A survey of polypropylene crosslinking initiated by thermal decomposition of peroxide is given. T... more A survey of polypropylene crosslinking initiated by thermal decomposition of peroxide is given. The role of coagents of the crosslinking is demonstrated and mainly consists in inhibition of macroradical fragmentation. The properties of crosslinked polypropylene as well as of crosslinked polypropylenepolyethylene blends are shown to depend strongly on the effectivity of crosslinking.
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology, 2015
Antibacterial modification of polymer veneers. The increase of the resistance to infections can b... more Antibacterial modification of polymer veneers. The increase of the resistance to infections can be achieved by plastic veneers, e.g. produced from low-density polyethylene (LDPE), surface treatment by substances containing antibacterial groups such as triclosan and chlorhexidine. This research has examined the impact of selected antibacterial substances immobilized on LDPE via poly acrylic acid (PAA) grafted on LDPE by low-temperature barrier discharge plasma. This surface treatment led to inhibition of Escherichia coli and Staphylococcus aureus adhesion; the former is causing intestinal disease, peritonitis, pneumonia and septicemia.
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Journal of Polymer Science: Polymer Symposia, Mar 8, 2007
ABSTRACT The present paper examines the possibility of the utilization of the bimolecular cumyl h... more ABSTRACT The present paper examines the possibility of the utilization of the bimolecular cumyl hydroperoxide redox decomposition, catalyzed by Co11 naphthenate for the polymer crosslinking. The study of the mechanism and the kinetics of this reaction was performed both in a model medium heptane and polymer or polymer solution. In the case of redox initiation, the value of the crosslinking efficiency was found to be about 0.4, and its decrease can be attributed mainly to the formation of ions and, partly, to recombination of peroxy radicals producing dialkyl peroxide. On the basis of data obtained concerning the efficiency and rate of the process, conclusions are made on its applicability, especially for the crosslinking below the melting point of a crystalline polymer, as is the case of the crosslinking of polyethylene films.
Nuclear Instruments and Methods in Physics Research, Jun 1, 2007
Abstract Neutron transmission imaging is recently finding still larger variety of applications. T... more Abstract Neutron transmission imaging is recently finding still larger variety of applications. The development of reliable neutron-detecting device is essential for the high-quality imaging. However, such neutron imaging detectors have been prepared usually based on CCD cameras. Recently, first semiconductor detectors with neutron converter layers are beginning to appear. GaAs-based structures are presently under investigation as the substrate for neutron converter layer coated detectors of fast neutrons. Two new neutron converter layers (primer & rubber based), similar to HDPE (high-density polyethylene) were designed, prepared and tested via 239 PuBe radioisotope neutron source.
The effect of various modifiers on the structure and properties of clay/natural rubber nanocompos... more The effect of various modifiers on the structure and properties of clay/natural rubber nanocomposites are investigated with the aim to evaluate the effect of size and structure of the modifier. Nanocomposites are prepared by melt intercalation method. Mechanical properties of the cured rubber containing nanoclay are compared with the reference compound without the filler. No improvement of mechanical properties is observed for small organic cations; however, stress and strain at break of clay/rubber nanocomposites increase with rising number of octyl chains in the interlayer spaces of organo-clays. Concerning organo-cations with the same number of carbon atoms, more effective are the modifiers with several shorter carbon chains compared to those with one long chain. The composites exhibit hybrid structure of nanocomposite and microcomposite as revealed by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The details of the structure are supported by DMTA and hysteresis measurements. V
ABSTRACT a b s t r a c t This paper reports strong, reversible actuation of nanocomposites on the... more ABSTRACT a b s t r a c t This paper reports strong, reversible actuation of nanocomposites on the base of ethylene vinyl acetate (EVA) filled with multiwalled (MWCNTs) and singlewalled carbon nanotubes (SWCNTs). The carbon nano-tubes (CNTs) dispersion within the EVA matrix was ensured with pyrene-based compatibilizer and the alignment of the CNTs within a matrix was induced by shear stress to 50% applied as a prerequisite for unilateral photo-actuation. The CNT dispersion within EVA matrix was characterized by transmission electron microscopy (TEM). The dependence of the actuation stress as a function of CNTs concentration, energy and intensity of light was studied. Stress variation of actuation and relaxation were evaluated. The photo-actuation responses showed contraction under illumination up to 170 kPa for EVA-CNTs-based nanocomposites. Repeatability of photo-actuation process up to 100 cycles was observed. High optical-to-mechanical energy conversion factor (Á M) of 55 MPa W −1 for EVA nanocomposite containing 0.1 wt.% MWCNT m during illumination by red light-emitted diode (LED) is reported.
... Fracture Behaviour of (3-Polypropylene as a Function of Processing Conditions 353 Eva Nezbedo... more ... Fracture Behaviour of (3-Polypropylene as a Function of Processing Conditions 353 Eva Nezbedova*, Vladimir Pospisil, Petr Bohaty, Bohumil Vlach * The ... Dumitru, Paul 215 Dzene, Anda 61 Erina, Natalia 73 Fahnrich, Jaromir 79 Fekete, Erika 9 Fortelny, Ivan 99 Fricova, Ol'ga ...
V INTERNATIONAL CONFERENCE ON TIMES OF POLYMERS (TOP) AND COMPOSITES, 2010
Biodegradable polymer/clay nanocomposites and/or composites based on poly(epsilo-caprolactone) (P... more Biodegradable polymer/clay nanocomposites and/or composites based on poly(epsilo-caprolactone) (PCL) were prepared by conventional melt mixing. Three kinds of clays, organomodified Cloisite 10A, Cloisite 15A and unmodified Cloisite with Na cations were used for preparation in different concentrations (from 1 to 10 wt%). The isothermal crystallization of the samples were studied by DSC at temperatures from 41 to 47° C. The obtained results of overall crystallization rate vc and half-time of crystallization t0.5 indicated that the filler presence in the PCL matrix leads to superposition of two opposing effects-nucleation and retardation. The different tendency of the changes of vc and t0.5 in the dependence of filler content was showed between samples with organomodified and unmodified fillers. It can be explained by different surface areas of modified and unmodified clays and proportional to an extent of filler exfoliation.
A procedure is described of grafting the acrylic acid onto an oxygen/ozone-activated metallocene ... more A procedure is described of grafting the acrylic acid onto an oxygen/ozone-activated metallocene poly(ethylene-co-propylene). Consequently, the grafted copolymer is applied as a component in a metallocene polyolefin-based hot-melt adhesive composition with increased adhesion. The surface properties and adhesion strength of the prepared hot-melt adhesive (HMA) were determined and used to account for the effect of grafting. The application of grafted polyolefin as one of the components of the HMA mixture provides significant increase in adhesive strength, and it also results in increased compatibility and negligible effects on the technological parameters of the final composition. The obtained results may have significant impact for the practical application of prepared HMA for book bonding.
of plasticized poly(lactic acid)/ poly(3-hydroxybutyrate)/carbon black mulching films during one ... more of plasticized poly(lactic acid)/ poly(3-hydroxybutyrate)/carbon black mulching films during one season of sweet pepper production, European
Crosslinking of polypropylene at 10-220 ~ was investigated. The process was initiated by radicals... more Crosslinking of polypropylene at 10-220 ~ was investigated. The process was initiated by radicals formed either by thermal or by u.v. decomposition of dicumyl peroxide. It was found that fragmentation of macroradicals is the most important reaction during thermal initiation and the crosslinking efficiency increases with decreasing temperature. For u.v. initiation, several chemical and physical factors are important; the efficiency is highest at 65 80'.
The thermal lag associated with the temperature ramping experiment in a dynamic mechanical analys... more The thermal lag associated with the temperature ramping experiment in a dynamic mechanical analysis is demonstrated on carbon black filled vulcanised rubber samples by using a DMTA MkIII from Rheometric Scientific. The importance of achieving thermal equilibrium on the sample before starting the measurement is emphasised. By running a combination of isothermal and ramping steps, the impact of thermal lag on the obtained dynamic mechanical properties can be estimated. For the measurement in tensile mode at a rate of heating of 2°C/min and vertical orientation of the driveshaft motion, the isothermal step applied at the sample glass transition temperature revealed that the temperature equilibration of the sample takes at least 15 min. Consequently, the storage modulus measured during the heating step is overestimated by around two times and the glass transition temperature is shifted to higher values. For the given chamber geometry, the bending mode of measurement exhibits a lower thermal lag than the tensile one. The experimental data indicate that the major factors responsible for thermal lag are heat transfer from the sample environment to the sample surface (which is given by the chamber design), sample position in the chamber and the mutual position of the sample and thermometer Pt-100. Based on the results presented, a recommendation for selecting the experimental conditions is given in order to recognise and minimise the effect of thermal lag on the data obtained by dynamic mechanical analysis.
The 1H–13C cross polarization nuclear magnetic resonance technique was used for the study of mole... more The 1H–13C cross polarization nuclear magnetic resonance technique was used for the study of molecular mobility in amorphous polylactic acid. The cross polarization buildup curves for methine and methyl functional groups measured at magic angle spinning rates of 4 and 10 kHz, under Hartmann–Hahn conditions determined from corresponding Hartmann–Hahn matching profiles, confirmed the presence of 1H–13C spin pairs isolated from lattice since transient oscillations were observed in the initial stages of buildup curves. The values of dipolar coupling constants derived from Fourier transforms of cross polarization buildup curves indicate the presence of rigid methine groups and two kinds of methyl functional groups which differ in mobility. This could be due to the presence of amorphous phase with chain aggregations and phase with less spatial restrictions in this material. Fitting of theoretical expressions to experimental data provided additional information on the cross polarization process in this material.
A survey of polypropylene crosslinking initiated by thermal decomposition of peroxide is given. T... more A survey of polypropylene crosslinking initiated by thermal decomposition of peroxide is given. The role of coagents of the crosslinking is demonstrated and mainly consists in inhibition of macroradical fragmentation. The properties of crosslinked polypropylene as well as of crosslinked polypropylenepolyethylene blends are shown to depend strongly on the effectivity of crosslinking.
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology, 2015
Antibacterial modification of polymer veneers. The increase of the resistance to infections can b... more Antibacterial modification of polymer veneers. The increase of the resistance to infections can be achieved by plastic veneers, e.g. produced from low-density polyethylene (LDPE), surface treatment by substances containing antibacterial groups such as triclosan and chlorhexidine. This research has examined the impact of selected antibacterial substances immobilized on LDPE via poly acrylic acid (PAA) grafted on LDPE by low-temperature barrier discharge plasma. This surface treatment led to inhibition of Escherichia coli and Staphylococcus aureus adhesion; the former is causing intestinal disease, peritonitis, pneumonia and septicemia.
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Journal of Polymer Science: Polymer Symposia, Mar 8, 2007
ABSTRACT The present paper examines the possibility of the utilization of the bimolecular cumyl h... more ABSTRACT The present paper examines the possibility of the utilization of the bimolecular cumyl hydroperoxide redox decomposition, catalyzed by Co11 naphthenate for the polymer crosslinking. The study of the mechanism and the kinetics of this reaction was performed both in a model medium heptane and polymer or polymer solution. In the case of redox initiation, the value of the crosslinking efficiency was found to be about 0.4, and its decrease can be attributed mainly to the formation of ions and, partly, to recombination of peroxy radicals producing dialkyl peroxide. On the basis of data obtained concerning the efficiency and rate of the process, conclusions are made on its applicability, especially for the crosslinking below the melting point of a crystalline polymer, as is the case of the crosslinking of polyethylene films.
Nuclear Instruments and Methods in Physics Research, Jun 1, 2007
Abstract Neutron transmission imaging is recently finding still larger variety of applications. T... more Abstract Neutron transmission imaging is recently finding still larger variety of applications. The development of reliable neutron-detecting device is essential for the high-quality imaging. However, such neutron imaging detectors have been prepared usually based on CCD cameras. Recently, first semiconductor detectors with neutron converter layers are beginning to appear. GaAs-based structures are presently under investigation as the substrate for neutron converter layer coated detectors of fast neutrons. Two new neutron converter layers (primer & rubber based), similar to HDPE (high-density polyethylene) were designed, prepared and tested via 239 PuBe radioisotope neutron source.
The effect of various modifiers on the structure and properties of clay/natural rubber nanocompos... more The effect of various modifiers on the structure and properties of clay/natural rubber nanocomposites are investigated with the aim to evaluate the effect of size and structure of the modifier. Nanocomposites are prepared by melt intercalation method. Mechanical properties of the cured rubber containing nanoclay are compared with the reference compound without the filler. No improvement of mechanical properties is observed for small organic cations; however, stress and strain at break of clay/rubber nanocomposites increase with rising number of octyl chains in the interlayer spaces of organo-clays. Concerning organo-cations with the same number of carbon atoms, more effective are the modifiers with several shorter carbon chains compared to those with one long chain. The composites exhibit hybrid structure of nanocomposite and microcomposite as revealed by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The details of the structure are supported by DMTA and hysteresis measurements. V
ABSTRACT a b s t r a c t This paper reports strong, reversible actuation of nanocomposites on the... more ABSTRACT a b s t r a c t This paper reports strong, reversible actuation of nanocomposites on the base of ethylene vinyl acetate (EVA) filled with multiwalled (MWCNTs) and singlewalled carbon nanotubes (SWCNTs). The carbon nano-tubes (CNTs) dispersion within the EVA matrix was ensured with pyrene-based compatibilizer and the alignment of the CNTs within a matrix was induced by shear stress to 50% applied as a prerequisite for unilateral photo-actuation. The CNT dispersion within EVA matrix was characterized by transmission electron microscopy (TEM). The dependence of the actuation stress as a function of CNTs concentration, energy and intensity of light was studied. Stress variation of actuation and relaxation were evaluated. The photo-actuation responses showed contraction under illumination up to 170 kPa for EVA-CNTs-based nanocomposites. Repeatability of photo-actuation process up to 100 cycles was observed. High optical-to-mechanical energy conversion factor (Á M) of 55 MPa W −1 for EVA nanocomposite containing 0.1 wt.% MWCNT m during illumination by red light-emitted diode (LED) is reported.
... Fracture Behaviour of (3-Polypropylene as a Function of Processing Conditions 353 Eva Nezbedo... more ... Fracture Behaviour of (3-Polypropylene as a Function of Processing Conditions 353 Eva Nezbedova*, Vladimir Pospisil, Petr Bohaty, Bohumil Vlach * The ... Dumitru, Paul 215 Dzene, Anda 61 Erina, Natalia 73 Fahnrich, Jaromir 79 Fekete, Erika 9 Fortelny, Ivan 99 Fricova, Ol'ga ...
V INTERNATIONAL CONFERENCE ON TIMES OF POLYMERS (TOP) AND COMPOSITES, 2010
Biodegradable polymer/clay nanocomposites and/or composites based on poly(epsilo-caprolactone) (P... more Biodegradable polymer/clay nanocomposites and/or composites based on poly(epsilo-caprolactone) (PCL) were prepared by conventional melt mixing. Three kinds of clays, organomodified Cloisite 10A, Cloisite 15A and unmodified Cloisite with Na cations were used for preparation in different concentrations (from 1 to 10 wt%). The isothermal crystallization of the samples were studied by DSC at temperatures from 41 to 47° C. The obtained results of overall crystallization rate vc and half-time of crystallization t0.5 indicated that the filler presence in the PCL matrix leads to superposition of two opposing effects-nucleation and retardation. The different tendency of the changes of vc and t0.5 in the dependence of filler content was showed between samples with organomodified and unmodified fillers. It can be explained by different surface areas of modified and unmodified clays and proportional to an extent of filler exfoliation.
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