J. Grebowicz - Academia.edu (original) (raw)
Papers by J. Grebowicz
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Journal of Macromolecular Science: Part A - Chemistry, 1982
ABSTRACT
Thin Solid Films, 1980
ABSTRACT
Polymer, 1985
Abstract Heat capacities at constant pressure and volume are calculated from full and partially a... more Abstract Heat capacities at constant pressure and volume are calculated from full and partially approximated normal mode frequency spectra for crystalline polyethylene, poly(oxymethylene), poly(oxyethylene), poly(oxytrimethylene), poly(oxytetramethylene), poly(oxyoctamethylene), poly(oxymethyleneoxyethylene), and poly(oxymethyleneoxytetramethylene). A calculation scheme using a Tarasov-function for 2 N skeletal modes and approximation of the residual normal modes from known data on polyethylene and poly(oxymethylene) is developed for all homologous, linear, aliphatic polyoxides. N is the number of CH 2 -groups in the repeating unit. Calculations can be carried out over the whole temperature range OK to melting. For θ-temperatures and constant A o for the C v − to − C p conversion, oxygenconcentration dependent curves are given. Recommended experimental data bank heat capacities agree to ±5% or better.
Polymer, 1988
A series of copolyesters derived from p-hydroxybenzoic acid (pHBA) and m-hydroxybenzoic acid (mHB... more A series of copolyesters derived from p-hydroxybenzoic acid (pHBA) and m-hydroxybenzoic acid (mHBA) have been prepared via the corresponding (trimethylsilyloxy)benzoyl chlorides. It is shown that this method ('silyl method') leads to random copolyesters of good stability against thermal degradation and the formation of blocky structures. Materials with a low content of pHBA crystallize in the lattice of poly(mHBA). Copolyesters containing high amounts (50-100 %) of pHBA have an increasing degree of crystallinity with increasing content of the linear para units. These materials crystallize within the unit cells of modifications I and II found for poly(pHBA). Polyesters having an intermediate range of compositions do not crystallize. The glass transition temperature is slightly lowered upon increasing the content of pHBA, and the range in which the transition takes place is broadened considerably. Polyesters with less than 50 % pHBA units form only an isotropic melt. The semicrystalline copolyesters containing 50 % and more pHBA exhibit a first-order transition to a mixture of the pseudo-hexagonal modification III of poly(pHBA) and an amorphous phase.
Polymer Blends, 1980
Blends of polymers are, in most cases, heterogeneous systems in which components partially preser... more Blends of polymers are, in most cases, heterogeneous systems in which components partially preserve their individual properties because of the incompatibility of polymers. In blends of semicrystalline polymers, the properties of components are strongly dependent on crystallinity and crystalline morphology. If the crystallizing polymer is dispersed in the blend, its properties are usually different from those in bulk. First of all this can be observed for polymers which crystallize forming supermolecular structures like the spherulites in which crystallization kinetics and resultant morphology are related to temperature dependent nucleation and growth rates of spherulites. In such polymers in the bulk when the nucleation rate is not very high, one nucleus can involve the crystallization in a relatively large volume, i.e. the volume of the final spherulite. In the blend in which the polymer is dispersed into small particles, the range of the influence of an individual nucleus is limited to the size of particles.
Polymer Journal, 1974
Two new mechanical models for the description of mechanical properties of two-component polymer b... more Two new mechanical models for the description of mechanical properties of two-component polymer blends are proposed. On the basis of these models the dependence of the dynamic complex moduli on the blend content is theoretically calculated. Results obtained theoretically are compared with experimental data for polyethylene and polypropylene blends.
Polymer, 2001
... d, Department of Chemical Engineering, National Chung Hsing Univeristy, 250 Kuokuang Road, Ta... more ... d, Department of Chemical Engineering, National Chung Hsing Univeristy, 250 Kuokuang Road, Taichung 402, Taiwan, ROC. ... ED calibration of the d-spacing was done using TlCl in a d-spacing range smaller than 0.384 nm, which is the largest spacing for TlCl. ...
Polymer, 1979
Abstract The surface morphology of the PP fibres with internal helical texture were studied. The ... more Abstract The surface morphology of the PP fibres with internal helical texture were studied. The studies were carried out by the direct observation of the untreated fibre surface, and by the ‘marked deformation’ method of microscopical objects using a ‘JEOL’ scanning electron microscope. The results showed the helical internal texture of these fibres.
![Research paper thumbnail of Reversible and irreversible heat capacity of poly[carbonyl(ethylene-co-propylene)] by temperature-modulated calorimetry](https://attachments.academia-assets.com/97897872/thumbnails/1.jpg)
](Journal of Polymer Science Part B: Polymer Physics, 2001
The heat capacity of poly(trimethylene terephthalate) (PTT) has been analyzed using temperature-m... more The heat capacity of poly(trimethylene terephthalate) (PTT) has been analyzed using temperature-modulated differential scanning calorimetry (TMDSC) and compared with results obtained earlier from adiabatic calorimetry and standard differential scanning calorimetry (DSC). Using quasi-isothermal TMDSC, the apparent reversing and nonreversing heat capacities were determined from 220 to 540 K, including glass and melting transitions. Truly reversible and time-dependent irreversible heat effects were separated. The extrapolated vibrational heat capacity of the solid and the total heat capacity of the liquid served as baselines for the analysis. As one approaches the melting region from lower temperature, semicrystalline PTT shows a reversing heat capacity, which is larger than that of the liquid, an observation that is common also for other polymers. This higher heat capacity is interpreted as a reversible surface or bulk melting and crystallization, which does not need to undergo molecular nucleation. Additional time-dependent, reversing contributions, dominating at temperatures even closer to the melting peak, are linked to reorganization and recrystallization (annealing), while the major melting is fully irreversible (nonreversing contribution).
Journal of Applied Polymer Science, 1989
Polytetrafluoroethylene as polymerized (virgin) was drawn, sintered, and annealed. By thermal ana... more Polytetrafluoroethylene as polymerized (virgin) was drawn, sintered, and annealed. By thermal analysis the changes in crystal type and crystallinity and melting kinetics was analyzed. I t is shown that this analysis permits control and optimization of the various processes. In addition, a new, high melting polytetrafluoroethylene (654 K) is described. It is assumed to be metastable due to strain in the surrounding amorphous fraction.
Colloid and Polymer Science, 1978
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Journal of Macromolecular Science: Part A - Chemistry, 1982
ABSTRACT
Thin Solid Films, 1980
ABSTRACT
Polymer, 1985
Abstract Heat capacities at constant pressure and volume are calculated from full and partially a... more Abstract Heat capacities at constant pressure and volume are calculated from full and partially approximated normal mode frequency spectra for crystalline polyethylene, poly(oxymethylene), poly(oxyethylene), poly(oxytrimethylene), poly(oxytetramethylene), poly(oxyoctamethylene), poly(oxymethyleneoxyethylene), and poly(oxymethyleneoxytetramethylene). A calculation scheme using a Tarasov-function for 2 N skeletal modes and approximation of the residual normal modes from known data on polyethylene and poly(oxymethylene) is developed for all homologous, linear, aliphatic polyoxides. N is the number of CH 2 -groups in the repeating unit. Calculations can be carried out over the whole temperature range OK to melting. For θ-temperatures and constant A o for the C v − to − C p conversion, oxygenconcentration dependent curves are given. Recommended experimental data bank heat capacities agree to ±5% or better.
Polymer, 1988
A series of copolyesters derived from p-hydroxybenzoic acid (pHBA) and m-hydroxybenzoic acid (mHB... more A series of copolyesters derived from p-hydroxybenzoic acid (pHBA) and m-hydroxybenzoic acid (mHBA) have been prepared via the corresponding (trimethylsilyloxy)benzoyl chlorides. It is shown that this method ('silyl method') leads to random copolyesters of good stability against thermal degradation and the formation of blocky structures. Materials with a low content of pHBA crystallize in the lattice of poly(mHBA). Copolyesters containing high amounts (50-100 %) of pHBA have an increasing degree of crystallinity with increasing content of the linear para units. These materials crystallize within the unit cells of modifications I and II found for poly(pHBA). Polyesters having an intermediate range of compositions do not crystallize. The glass transition temperature is slightly lowered upon increasing the content of pHBA, and the range in which the transition takes place is broadened considerably. Polyesters with less than 50 % pHBA units form only an isotropic melt. The semicrystalline copolyesters containing 50 % and more pHBA exhibit a first-order transition to a mixture of the pseudo-hexagonal modification III of poly(pHBA) and an amorphous phase.
Polymer Blends, 1980
Blends of polymers are, in most cases, heterogeneous systems in which components partially preser... more Blends of polymers are, in most cases, heterogeneous systems in which components partially preserve their individual properties because of the incompatibility of polymers. In blends of semicrystalline polymers, the properties of components are strongly dependent on crystallinity and crystalline morphology. If the crystallizing polymer is dispersed in the blend, its properties are usually different from those in bulk. First of all this can be observed for polymers which crystallize forming supermolecular structures like the spherulites in which crystallization kinetics and resultant morphology are related to temperature dependent nucleation and growth rates of spherulites. In such polymers in the bulk when the nucleation rate is not very high, one nucleus can involve the crystallization in a relatively large volume, i.e. the volume of the final spherulite. In the blend in which the polymer is dispersed into small particles, the range of the influence of an individual nucleus is limited to the size of particles.
Polymer Journal, 1974
Two new mechanical models for the description of mechanical properties of two-component polymer b... more Two new mechanical models for the description of mechanical properties of two-component polymer blends are proposed. On the basis of these models the dependence of the dynamic complex moduli on the blend content is theoretically calculated. Results obtained theoretically are compared with experimental data for polyethylene and polypropylene blends.
Polymer, 2001
... d, Department of Chemical Engineering, National Chung Hsing Univeristy, 250 Kuokuang Road, Ta... more ... d, Department of Chemical Engineering, National Chung Hsing Univeristy, 250 Kuokuang Road, Taichung 402, Taiwan, ROC. ... ED calibration of the d-spacing was done using TlCl in a d-spacing range smaller than 0.384 nm, which is the largest spacing for TlCl. ...
Polymer, 1979
Abstract The surface morphology of the PP fibres with internal helical texture were studied. The ... more Abstract The surface morphology of the PP fibres with internal helical texture were studied. The studies were carried out by the direct observation of the untreated fibre surface, and by the ‘marked deformation’ method of microscopical objects using a ‘JEOL’ scanning electron microscope. The results showed the helical internal texture of these fibres.
Journal of Polymer Science Part B: Polymer Physics, 2001
The heat capacity of poly(trimethylene terephthalate) (PTT) has been analyzed using temperature-m... more The heat capacity of poly(trimethylene terephthalate) (PTT) has been analyzed using temperature-modulated differential scanning calorimetry (TMDSC) and compared with results obtained earlier from adiabatic calorimetry and standard differential scanning calorimetry (DSC). Using quasi-isothermal TMDSC, the apparent reversing and nonreversing heat capacities were determined from 220 to 540 K, including glass and melting transitions. Truly reversible and time-dependent irreversible heat effects were separated. The extrapolated vibrational heat capacity of the solid and the total heat capacity of the liquid served as baselines for the analysis. As one approaches the melting region from lower temperature, semicrystalline PTT shows a reversing heat capacity, which is larger than that of the liquid, an observation that is common also for other polymers. This higher heat capacity is interpreted as a reversible surface or bulk melting and crystallization, which does not need to undergo molecular nucleation. Additional time-dependent, reversing contributions, dominating at temperatures even closer to the melting peak, are linked to reorganization and recrystallization (annealing), while the major melting is fully irreversible (nonreversing contribution).
Journal of Applied Polymer Science, 1989
Polytetrafluoroethylene as polymerized (virgin) was drawn, sintered, and annealed. By thermal ana... more Polytetrafluoroethylene as polymerized (virgin) was drawn, sintered, and annealed. By thermal analysis the changes in crystal type and crystallinity and melting kinetics was analyzed. I t is shown that this analysis permits control and optimization of the various processes. In addition, a new, high melting polytetrafluoroethylene (654 K) is described. It is assumed to be metastable due to strain in the surrounding amorphous fraction.
Colloid and Polymer Science, 1978