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Papers by Riccardo Bianchi

Research paper thumbnail of Axially oriented guest induced crystallization in syndiotactic polystyrene unstretched fibers

Research paper thumbnail of Influence of spinning velocity on mechanical and structural behavior of PET/nylon 6 fibers

J Appl Polym Sci, 1995

Influence of spinning velocities on the mechanical and structural properties of polyethylene tere... more Influence of spinning velocities on the mechanical and structural properties of polyethylene terephthalate (PET)/nylon 6 blend fibers have been reported. Fibers of PET/nylon 6 containing a small percentage of nylon (5% by weight) have been melt-spun at 3 different spinning velocities (2,900; 3,200; 3,600 m/min). The fibers have been characterized by thermal, morphological, structural, and mechanical analysis. Various techniques such as SEM, DSC, X-ray diffraction, hot water shrinkage (HWS), viscosity, and birefringence have been used. SEM analysis revealed that in the blend, nylon 6 is well-dispersed as spheres in the PET matrix. The blend shows a marked decrease in the melt-flow index, which in turn leads to a beneficial effect on the rheological properties of the PET without negatively influencing its mechanical characteristics. This finding results in a saving on energetical requirements of the processing, as both temperature and pressure of spinning can be decreased. 0 1995 John Wiley & Sons, Inc.

Research paper thumbnail of Process for the solid state polycondensation of polyamide resins

Research paper thumbnail of Disordered nanoporous crystalline form of syndiotactic polystyrene, process for its preparation and articles comprising the same

ABSTRACT Syndiotactic polystyrene (s-PS) in disordered nanoporous cryst. form, when characterized... more ABSTRACT Syndiotactic polystyrene (s-PS) in disordered nanoporous cryst. form, when characterized using an X-ray diffraction spectrum as measured by an automatic powder diffractometer, has only two peaks at 2θ (CuKα) < 15° with maxima in the intervals 8.7° < 2θ (CuKα) < 9.8° and 13.0° < 2θ (CuKα) < 13.8° and with a half height width of at least 2°. The disordered nanoporous cryst. form of s-PS has empty cryst. nanoscale cavities, and may absorb low mol. wt. mols., thus being useful as an active packaging material. [on SciFinder(R)]

Research paper thumbnail of On the mesomorphic form of poly(ethylene terephthalate)

Macromolecules, 1992

The conformation and the packing of poly(ethy1ene terephthalate) (PET) chains in the mesomorphic ... more The conformation and the packing of poly(ethy1ene terephthalate) (PET) chains in the mesomorphic form have been investigated by accurate X-ray diffraction measurements, conformational energy analysis, and calculations of Fourier transforms of models. The X-ray diffraction pattern presented here is richer than those previously reported. In particular, besides the known meridional peaks at { = l/c and 3/c, corresponding to a periodicity of 10.3 A, a stronger meridional peak at { = 5/c has been shown. The reported Fourier transform calculations of isolated-chain models indicate that the experimental diffraction pattern of the mesomorphic form of PET can be qualitatively accounted for by extended linear chains obtained by random sequences of monomeric units in different minimum energy conformations. These random sequences of monomeric units generate chains in which any long-range correlation between the planes of the phenylene rings, along the chain, is absent.

Research paper thumbnail of Effect of moisture on the crystallization behavior of PET from the quenched amorphous phase

Journal of Applied Polymer Science, 1991

ABSTRACT

Research paper thumbnail of Crystallization of poly(ethylene terephthalate) (PET) from the oriented mesomorphic form

Journal of Applied Polymer Science, 1994

Research paper thumbnail of Disordered Nanoporous Crystalline Form of Syndiotactic Polystyrene, Process for Its Preparation and Articles Comprising the Same

ABSTRACT Syndiotactic polystyrene (s-PS) in disordered nanoporous cryst. form, when characterized... more ABSTRACT Syndiotactic polystyrene (s-PS) in disordered nanoporous cryst. form, when characterized using an X-ray diffraction spectrum as measured by an automatic powder diffractometer, has only two peaks at 2θ (CuKα) < 15° with maxima in the intervals 8.7° < 2θ (CuKα) < 9.8° and 13.0° < 2θ (CuKα) < 13.8° and with a half height width of at least 2°. The disordered nanoporous cryst. form of s-PS has empty cryst. nanoscale cavities, and may absorb low mol. wt. mols., thus being useful as an active packaging material. [on SciFinder(R)]

Research paper thumbnail of Axially oriented guest induced crystallization in syndiotactic polystyrene unstretched fibers

Research paper thumbnail of Influence of spinning velocity on mechanical and structural behavior of PET/nylon 6 fibers

J Appl Polym Sci, 1995

Influence of spinning velocities on the mechanical and structural properties of polyethylene tere... more Influence of spinning velocities on the mechanical and structural properties of polyethylene terephthalate (PET)/nylon 6 blend fibers have been reported. Fibers of PET/nylon 6 containing a small percentage of nylon (5% by weight) have been melt-spun at 3 different spinning velocities (2,900; 3,200; 3,600 m/min). The fibers have been characterized by thermal, morphological, structural, and mechanical analysis. Various techniques such as SEM, DSC, X-ray diffraction, hot water shrinkage (HWS), viscosity, and birefringence have been used. SEM analysis revealed that in the blend, nylon 6 is well-dispersed as spheres in the PET matrix. The blend shows a marked decrease in the melt-flow index, which in turn leads to a beneficial effect on the rheological properties of the PET without negatively influencing its mechanical characteristics. This finding results in a saving on energetical requirements of the processing, as both temperature and pressure of spinning can be decreased. 0 1995 John Wiley & Sons, Inc.

Research paper thumbnail of Process for the solid state polycondensation of polyamide resins

Research paper thumbnail of Disordered nanoporous crystalline form of syndiotactic polystyrene, process for its preparation and articles comprising the same

ABSTRACT Syndiotactic polystyrene (s-PS) in disordered nanoporous cryst. form, when characterized... more ABSTRACT Syndiotactic polystyrene (s-PS) in disordered nanoporous cryst. form, when characterized using an X-ray diffraction spectrum as measured by an automatic powder diffractometer, has only two peaks at 2θ (CuKα) < 15° with maxima in the intervals 8.7° < 2θ (CuKα) < 9.8° and 13.0° < 2θ (CuKα) < 13.8° and with a half height width of at least 2°. The disordered nanoporous cryst. form of s-PS has empty cryst. nanoscale cavities, and may absorb low mol. wt. mols., thus being useful as an active packaging material. [on SciFinder(R)]

Research paper thumbnail of On the mesomorphic form of poly(ethylene terephthalate)

Macromolecules, 1992

The conformation and the packing of poly(ethy1ene terephthalate) (PET) chains in the mesomorphic ... more The conformation and the packing of poly(ethy1ene terephthalate) (PET) chains in the mesomorphic form have been investigated by accurate X-ray diffraction measurements, conformational energy analysis, and calculations of Fourier transforms of models. The X-ray diffraction pattern presented here is richer than those previously reported. In particular, besides the known meridional peaks at { = l/c and 3/c, corresponding to a periodicity of 10.3 A, a stronger meridional peak at { = 5/c has been shown. The reported Fourier transform calculations of isolated-chain models indicate that the experimental diffraction pattern of the mesomorphic form of PET can be qualitatively accounted for by extended linear chains obtained by random sequences of monomeric units in different minimum energy conformations. These random sequences of monomeric units generate chains in which any long-range correlation between the planes of the phenylene rings, along the chain, is absent.

Research paper thumbnail of Effect of moisture on the crystallization behavior of PET from the quenched amorphous phase

Journal of Applied Polymer Science, 1991

ABSTRACT

Research paper thumbnail of Crystallization of poly(ethylene terephthalate) (PET) from the oriented mesomorphic form

Journal of Applied Polymer Science, 1994

Research paper thumbnail of Disordered Nanoporous Crystalline Form of Syndiotactic Polystyrene, Process for Its Preparation and Articles Comprising the Same

ABSTRACT Syndiotactic polystyrene (s-PS) in disordered nanoporous cryst. form, when characterized... more ABSTRACT Syndiotactic polystyrene (s-PS) in disordered nanoporous cryst. form, when characterized using an X-ray diffraction spectrum as measured by an automatic powder diffractometer, has only two peaks at 2θ (CuKα) < 15° with maxima in the intervals 8.7° < 2θ (CuKα) < 9.8° and 13.0° < 2θ (CuKα) < 13.8° and with a half height width of at least 2°. The disordered nanoporous cryst. form of s-PS has empty cryst. nanoscale cavities, and may absorb low mol. wt. mols., thus being useful as an active packaging material. [on SciFinder(R)]