Maria Nobile | Università degli Studi di Salerno (original) (raw)
Papers by Maria Nobile
Molecular Crystals and Liquid Crystals Incorporating Nonlinear Optics, 1987
DOMENICO ACIERNO", EUGENIO AMENDOLA, COSIMO CARFAGNA, LUIGI NICOLAIS, and ROSSELLA NOBILE *I... more DOMENICO ACIERNO", EUGENIO AMENDOLA, COSIMO CARFAGNA, LUIGI NICOLAIS, and ROSSELLA NOBILE *Istituto di Ingegneria Chimico-Alimentare, Un.of Salerno, ... Dipartimento di Ingegneria dei Materiali e della Produzione, Un. of Naples, Naples, Italy
Polymer Degradation and Stability, 2015
ABSTRACT In this work we demonstrate that aqueous hydrogen peroxide is an effective reagent for c... more ABSTRACT In this work we demonstrate that aqueous hydrogen peroxide is an effective reagent for chain scissioning or vis-breaking of polypropylene during melt-processing to produce controlled rheology product. The novel process involves the direct injection of aqueous hydrogen peroxide into the polypropylene melt under pressure. The polypropylene produced has reduced molar mass, narrowed molar mass distribution), and is indistinguishable in terms of melt flow rate, molar mass distribution, crystallinity and melt rheology from conventionally vis-broken polypropylene produced using an organic peroxide (2,5-dimethyl-2,5-di-tert-butylperoxyhexane (DHBP)). However, the polypropylene produced in the current process is notably free of the organic volatiles formed as by-products in the case of organic peroxides such as DHBP.
Rheologica Acta, 2006
In this work, the rheological properties of the wholly aromatic random copolyester HBA/HNA (60/40... more In this work, the rheological properties of the wholly aromatic random copolyester HBA/HNA (60/40), the commercial copolyesteramide Vectra B950, and the semiflexible commercial copolyester Rodrun 3000, PET/HBA 40/60, were investigated. All the thermotropic liquid crystalline polymers (TLCPs) show linear viscoelastic behavior at small strain amplitudes. The strain sweep experiments have clearly indicated that the onset for non linearity significantly decreases
Polymer Engineering & Science, 2005
ABSTRACT In the present work, the influence of well-defined simple shear flow histories on the is... more ABSTRACT In the present work, the influence of well-defined simple shear flow histories on the isothermal crystallization of an isotactic polypropylene (i-PP) has been investigated. At first, the research of the flow conditions in terms of temperature, shear rate () and shear strain () has been performed by means of the rheological technique. The continuous shearing analysis enabled us to build the flow curve at 144°C showing a Newtonian region as well as a shear-thinning zone. Indeed, for above a critical value, the molecular orientation occurring during flow provides a kinetic promotion of the crystallization process. In the rheological step-shear flow analysis, an increase of the flow sensitivity parameter, kS/kQ, with increasing the shear rate at a constant strain ( = 150) is observed. The structure of the crystallized samples has been investigated by differential scanning calorimetry (DSC) and wide angle X-ray scattering (WAXS) methods. In agreement with the DSC, the WAXS results show that crystals with a certain bimodal distribution are generated in the samples crystallized under step-shear flow conditions. A small orientation of the (110) plane of the i-PP -phase crystals is also detected. POLYM. ENG. SCI., 45:153–162, 2005. © 2005 Society of Plastics Engineers.
Polymer Engineering & Science, 1996
ABSTRACT The rheological properties of the novel engineering thermoplastic phenophthalein poly(et... more ABSTRACT The rheological properties of the novel engineering thermoplastic phenophthalein poly(ether ether ketone) (PEK-C) have been investigated using both a rotational and a capillary rheometer. The dependence of the viscosity on the shear rate and temperature was obtained. The activation energy was evaluated both from the Arrhenius and the Williams-Landel-Ferry (WLF) equation. An estimate for the proper Eη (dependent only on the chemical structure of the polymer) has been found from the WLF equation at temperatures about Tg + 200°C. Measurements of the die swell have been performed. The first normal stress differences were evaluated from the die swell results and compared with the values obtained from the rotational rheometer at low shear rates.
Macromolecular Symposia, 2002
ABSTRACT In the present work the kinetics of the isothermal quiescent crystallization of the isot... more ABSTRACT In the present work the kinetics of the isothermal quiescent crystallization of the isotactic Poly(1-butene) (i-PB) is analyzed by means of rheological measurements and is used as an internal reference to study the effects of the shear flow. In particular, the flow-induced crystallization of two i-PB samples with different molecular weight is investigated by step-shear experiments at the crystallization temperature, TC, of 95°C. Indeed, with step-shear experiments the effects of the applied shear rate and shear strain on the crystallization kinetics can be separately analyzed. In all the cases the overall-crystallization rate constant, k, defined as the inverse of the half-time of crystallization (t0.5) has been evaluated. The results show that a critical shear rate (at a constant shear strain) and a critical shear strain (at a constant shear rate) are necessary to obtain the enhancement of k. These results significantly depend on the molecular weight revealing a stronger sensitivity to flow for the higher molecular weight sample. On the contrary, in the quiescent experiments no evidence of relevant molecular weight effects is detected. The in-situ optical analysis has shown that faster growth rates and a strong enhancement of nucleation density are observed in the step-shear experiments compared to the quiescent case.
Macromolecular Symposia, 2005
ABSTRACT In this work the rheological behaviour of different Mw samples of a thermotropic liquid ... more ABSTRACT In this work the rheological behaviour of different Mw samples of a thermotropic liquid crystalline polymer (TLCP), the random copolymer HBA/HNA 73/27 produced by Ticona, has been investigated. The linear viscoelastic behavior has been discussed. The G′ (shear storage modulus) and G″ (shear loss modulus) have been monitored as a function of frequency and of different annealing times. Rheological data obtained in steady state conditions have been used to define the viscosity flow curves for the different MW samples. In all the cases a three regions flow curve has been detected, with the plateau zone being Mw dependent.
Macromolecular Symposia, 2002
ABSTRACT In this work the kinetics of the isothermal crystallization from the melt of isotactic p... more ABSTRACT In this work the kinetics of the isothermal crystallization from the melt of isotactic polyolefins in quiescent conditions as well as after the application of a step-shear flow is investigated by means of rheological measurements. It is shown that the kinetics of the crystallization, as measured by the increase of the storage modulus, is not affected by the strain amplitude and the frequency of the oscillation, once they are properly chosen.A strong enhancement of the crystallization kinetics has been obtained when the step-shear flow was applied at the crystallization temperature TC=92°C for two different molecular weight poly(1-butene) samples (i-PB400 and i-PB200) and at TC=137°C for a polypropylene (i-PP). In particular, the overall-crystallization rate constants of the i-PB400 increased with increasing the applied shear rate at a constant total strain of 60. At higher shear flow temperatures slower kinetics occurred in all the cases until the effect of the applied shear flow was lost. Moreover, the effect of the molecular weight on the flow induced crystallization phenomenon is investigated on the two i-PB samples and the results have clearly shown that the higher molecular weight i-PB200 polymer is much more sensitive than the i-PB400 to the flow history.
Journal of Rheology, 2004
Journal of Rheology, 1994
Current Opinion in Solid State and Materials Science, 2004
... The microscale analogue to the current nanocomposite material is a carbon fiber/epoxy laminat... more ... The microscale analogue to the current nanocomposite material is a carbon fiber/epoxy laminate: essentially ... A 20 nm thick polymer/aligned CNT 'nano-lamina' may in fact be desirable, but ... Including one in which a (10,10) singlewall carbon nanotube (SWNT) pulled out from a ...
Epidemiology and Psychiatric Sciences
This Section of Epidemiology and Psychiatric Sciences regularly appears in each issue of the Jour... more This Section of Epidemiology and Psychiatric Sciences regularly appears in each issue of the Journal to describe relevant studies investigating the relationship between neurobiology and psychosocial psychiatry in major psychoses. The aim of these Editorials is to provide a better understanding of the neural basis of psychopathology and clinical features of these disorders, in order to raise new perspectives in everyday clinical practice. Paolo Brambilla, Section Editor and Michele Tansella, Editor EPS
Epidemiology and Psychiatric Sciences
This Section of Epidemiology and Psychiatric Sciences regularly appears in each issue of the Jour... more This Section of Epidemiology and Psychiatric Sciences regularly appears in each issue of the Journal to describe relevant studies investigating the relationship between neurobiology and psychosocial psychiatry in major psychoses. The aim of these Editorials is to provide a better understanding of the neural basis of psycho pathology and clinical features of these disorders, in order to raise new perspectives in everyday clinical practice. Paolo Brambilla, Section Editor and Michele Tansella, Editor EPS
Epidemiology and psychiatric sciences, 2013
In a short series of articles, we will review the evidence for genotype by environment interactio... more In a short series of articles, we will review the evidence for genotype by environment interaction (G × E) in developmental psychopathology. We will focus specifically on the characteristics of types of exposure assessed with respect to both their methods and findings. This article aims to review the studies exploring the effects of the child's broader social ecology on child and adolescent internalizing and externalizing psychopathology, based on a G × E perspective.
Epidemiology and psychiatric sciences, 2012
In a short series of articles, we will review the evidence for genotype by environment interactio... more In a short series of articles, we will review the evidence for genotype by environment interaction (G × E) in developmental psychopathology. We will focus specifically on the characteristics of types of exposure assessed with respect to both their methods and findings. This article aims to review the studies exploring the effects of child maltreatment on children, adolescents and young adults closer in time to maltreatment experience, in a G × E perspective.
Epidemiology and psychiatric sciences, 2013
In a short series of articles, we will review the evidence for genotype by environment interactio... more In a short series of articles, we will review the evidence for genotype by environment interaction (G × E) in developmental psychopathology. We will focus specifically on the characteristics of types of exposure assessed with respect to both their methods and findings. This article aims to review the studies exploring the moderating role of serotonin transporter on the effect of environmental adversities over time, particularly during childhood and adolescence, which is when level of internalizing symptoms and prevalence of mood disorders change substantially. Environmental adversities will not include abuse and maltreatment that have been reviewed before (see Bellani et al. 2012) and child's broader social ecology that will be reviewed in the next section.
Science and Engineering of Composite Materials, 1989
An inversion procedure for converting linear viscoelastic properties of polymer melts into molecu... more An inversion procedure for converting linear viscoelastic properties of polymer melts into molecular weight distribution (MWD) described by the generalized exponential function (GEX) has been implemented and applied in a previous work (Cocchini F, Nobile MR. Rheol Acta 42:232-242, 2003). It is based on the elegant relationship between the relaxation spectrum and the MWD function proposed by Thimm W, Friedrich C, Marth M. J Rheol 43: 1663-1672 (1999). In the present paper, such a methodology has been generalized to properly account for sharp MWDs, in particular, nearly monodisperse or blends of nearly monodisperse polymer samples. The generalized relationship has been verified and calibrated using the BSW kernel (Baumgaertel M, Schausberger A, Winter HH. Rheol Acta 29: [400][401][402][403][404][405][406][407][408] 1990) to describe the rheological behavior of some Polystyrene samples from the literature, in terms of the known MWD. Then, it has been successfully applied to the inversion problem for a wider set of samples, with both broad and sharp distributions. The Rouse contribution at high frequencies and the accelerating effect on the relaxation times due to polydispersion have been also addressed.
Molecular Crystals and Liquid Crystals Incorporating Nonlinear Optics, 1987
DOMENICO ACIERNO", EUGENIO AMENDOLA, COSIMO CARFAGNA, LUIGI NICOLAIS, and ROSSELLA NOBILE *I... more DOMENICO ACIERNO", EUGENIO AMENDOLA, COSIMO CARFAGNA, LUIGI NICOLAIS, and ROSSELLA NOBILE *Istituto di Ingegneria Chimico-Alimentare, Un.of Salerno, ... Dipartimento di Ingegneria dei Materiali e della Produzione, Un. of Naples, Naples, Italy
Polymer Degradation and Stability, 2015
ABSTRACT In this work we demonstrate that aqueous hydrogen peroxide is an effective reagent for c... more ABSTRACT In this work we demonstrate that aqueous hydrogen peroxide is an effective reagent for chain scissioning or vis-breaking of polypropylene during melt-processing to produce controlled rheology product. The novel process involves the direct injection of aqueous hydrogen peroxide into the polypropylene melt under pressure. The polypropylene produced has reduced molar mass, narrowed molar mass distribution), and is indistinguishable in terms of melt flow rate, molar mass distribution, crystallinity and melt rheology from conventionally vis-broken polypropylene produced using an organic peroxide (2,5-dimethyl-2,5-di-tert-butylperoxyhexane (DHBP)). However, the polypropylene produced in the current process is notably free of the organic volatiles formed as by-products in the case of organic peroxides such as DHBP.
Rheologica Acta, 2006
In this work, the rheological properties of the wholly aromatic random copolyester HBA/HNA (60/40... more In this work, the rheological properties of the wholly aromatic random copolyester HBA/HNA (60/40), the commercial copolyesteramide Vectra B950, and the semiflexible commercial copolyester Rodrun 3000, PET/HBA 40/60, were investigated. All the thermotropic liquid crystalline polymers (TLCPs) show linear viscoelastic behavior at small strain amplitudes. The strain sweep experiments have clearly indicated that the onset for non linearity significantly decreases
Polymer Engineering & Science, 2005
ABSTRACT In the present work, the influence of well-defined simple shear flow histories on the is... more ABSTRACT In the present work, the influence of well-defined simple shear flow histories on the isothermal crystallization of an isotactic polypropylene (i-PP) has been investigated. At first, the research of the flow conditions in terms of temperature, shear rate () and shear strain () has been performed by means of the rheological technique. The continuous shearing analysis enabled us to build the flow curve at 144°C showing a Newtonian region as well as a shear-thinning zone. Indeed, for above a critical value, the molecular orientation occurring during flow provides a kinetic promotion of the crystallization process. In the rheological step-shear flow analysis, an increase of the flow sensitivity parameter, kS/kQ, with increasing the shear rate at a constant strain ( = 150) is observed. The structure of the crystallized samples has been investigated by differential scanning calorimetry (DSC) and wide angle X-ray scattering (WAXS) methods. In agreement with the DSC, the WAXS results show that crystals with a certain bimodal distribution are generated in the samples crystallized under step-shear flow conditions. A small orientation of the (110) plane of the i-PP -phase crystals is also detected. POLYM. ENG. SCI., 45:153–162, 2005. © 2005 Society of Plastics Engineers.
Polymer Engineering & Science, 1996
ABSTRACT The rheological properties of the novel engineering thermoplastic phenophthalein poly(et... more ABSTRACT The rheological properties of the novel engineering thermoplastic phenophthalein poly(ether ether ketone) (PEK-C) have been investigated using both a rotational and a capillary rheometer. The dependence of the viscosity on the shear rate and temperature was obtained. The activation energy was evaluated both from the Arrhenius and the Williams-Landel-Ferry (WLF) equation. An estimate for the proper Eη (dependent only on the chemical structure of the polymer) has been found from the WLF equation at temperatures about Tg + 200°C. Measurements of the die swell have been performed. The first normal stress differences were evaluated from the die swell results and compared with the values obtained from the rotational rheometer at low shear rates.
Macromolecular Symposia, 2002
ABSTRACT In the present work the kinetics of the isothermal quiescent crystallization of the isot... more ABSTRACT In the present work the kinetics of the isothermal quiescent crystallization of the isotactic Poly(1-butene) (i-PB) is analyzed by means of rheological measurements and is used as an internal reference to study the effects of the shear flow. In particular, the flow-induced crystallization of two i-PB samples with different molecular weight is investigated by step-shear experiments at the crystallization temperature, TC, of 95°C. Indeed, with step-shear experiments the effects of the applied shear rate and shear strain on the crystallization kinetics can be separately analyzed. In all the cases the overall-crystallization rate constant, k, defined as the inverse of the half-time of crystallization (t0.5) has been evaluated. The results show that a critical shear rate (at a constant shear strain) and a critical shear strain (at a constant shear rate) are necessary to obtain the enhancement of k. These results significantly depend on the molecular weight revealing a stronger sensitivity to flow for the higher molecular weight sample. On the contrary, in the quiescent experiments no evidence of relevant molecular weight effects is detected. The in-situ optical analysis has shown that faster growth rates and a strong enhancement of nucleation density are observed in the step-shear experiments compared to the quiescent case.
Macromolecular Symposia, 2005
ABSTRACT In this work the rheological behaviour of different Mw samples of a thermotropic liquid ... more ABSTRACT In this work the rheological behaviour of different Mw samples of a thermotropic liquid crystalline polymer (TLCP), the random copolymer HBA/HNA 73/27 produced by Ticona, has been investigated. The linear viscoelastic behavior has been discussed. The G′ (shear storage modulus) and G″ (shear loss modulus) have been monitored as a function of frequency and of different annealing times. Rheological data obtained in steady state conditions have been used to define the viscosity flow curves for the different MW samples. In all the cases a three regions flow curve has been detected, with the plateau zone being Mw dependent.
Macromolecular Symposia, 2002
ABSTRACT In this work the kinetics of the isothermal crystallization from the melt of isotactic p... more ABSTRACT In this work the kinetics of the isothermal crystallization from the melt of isotactic polyolefins in quiescent conditions as well as after the application of a step-shear flow is investigated by means of rheological measurements. It is shown that the kinetics of the crystallization, as measured by the increase of the storage modulus, is not affected by the strain amplitude and the frequency of the oscillation, once they are properly chosen.A strong enhancement of the crystallization kinetics has been obtained when the step-shear flow was applied at the crystallization temperature TC=92°C for two different molecular weight poly(1-butene) samples (i-PB400 and i-PB200) and at TC=137°C for a polypropylene (i-PP). In particular, the overall-crystallization rate constants of the i-PB400 increased with increasing the applied shear rate at a constant total strain of 60. At higher shear flow temperatures slower kinetics occurred in all the cases until the effect of the applied shear flow was lost. Moreover, the effect of the molecular weight on the flow induced crystallization phenomenon is investigated on the two i-PB samples and the results have clearly shown that the higher molecular weight i-PB200 polymer is much more sensitive than the i-PB400 to the flow history.
Journal of Rheology, 2004
Journal of Rheology, 1994
Current Opinion in Solid State and Materials Science, 2004
... The microscale analogue to the current nanocomposite material is a carbon fiber/epoxy laminat... more ... The microscale analogue to the current nanocomposite material is a carbon fiber/epoxy laminate: essentially ... A 20 nm thick polymer/aligned CNT 'nano-lamina' may in fact be desirable, but ... Including one in which a (10,10) singlewall carbon nanotube (SWNT) pulled out from a ...
Epidemiology and Psychiatric Sciences
This Section of Epidemiology and Psychiatric Sciences regularly appears in each issue of the Jour... more This Section of Epidemiology and Psychiatric Sciences regularly appears in each issue of the Journal to describe relevant studies investigating the relationship between neurobiology and psychosocial psychiatry in major psychoses. The aim of these Editorials is to provide a better understanding of the neural basis of psychopathology and clinical features of these disorders, in order to raise new perspectives in everyday clinical practice. Paolo Brambilla, Section Editor and Michele Tansella, Editor EPS
Epidemiology and Psychiatric Sciences
This Section of Epidemiology and Psychiatric Sciences regularly appears in each issue of the Jour... more This Section of Epidemiology and Psychiatric Sciences regularly appears in each issue of the Journal to describe relevant studies investigating the relationship between neurobiology and psychosocial psychiatry in major psychoses. The aim of these Editorials is to provide a better understanding of the neural basis of psycho pathology and clinical features of these disorders, in order to raise new perspectives in everyday clinical practice. Paolo Brambilla, Section Editor and Michele Tansella, Editor EPS
Epidemiology and psychiatric sciences, 2013
In a short series of articles, we will review the evidence for genotype by environment interactio... more In a short series of articles, we will review the evidence for genotype by environment interaction (G × E) in developmental psychopathology. We will focus specifically on the characteristics of types of exposure assessed with respect to both their methods and findings. This article aims to review the studies exploring the effects of the child's broader social ecology on child and adolescent internalizing and externalizing psychopathology, based on a G × E perspective.
Epidemiology and psychiatric sciences, 2012
In a short series of articles, we will review the evidence for genotype by environment interactio... more In a short series of articles, we will review the evidence for genotype by environment interaction (G × E) in developmental psychopathology. We will focus specifically on the characteristics of types of exposure assessed with respect to both their methods and findings. This article aims to review the studies exploring the effects of child maltreatment on children, adolescents and young adults closer in time to maltreatment experience, in a G × E perspective.
Epidemiology and psychiatric sciences, 2013
In a short series of articles, we will review the evidence for genotype by environment interactio... more In a short series of articles, we will review the evidence for genotype by environment interaction (G × E) in developmental psychopathology. We will focus specifically on the characteristics of types of exposure assessed with respect to both their methods and findings. This article aims to review the studies exploring the moderating role of serotonin transporter on the effect of environmental adversities over time, particularly during childhood and adolescence, which is when level of internalizing symptoms and prevalence of mood disorders change substantially. Environmental adversities will not include abuse and maltreatment that have been reviewed before (see Bellani et al. 2012) and child's broader social ecology that will be reviewed in the next section.
Science and Engineering of Composite Materials, 1989
An inversion procedure for converting linear viscoelastic properties of polymer melts into molecu... more An inversion procedure for converting linear viscoelastic properties of polymer melts into molecular weight distribution (MWD) described by the generalized exponential function (GEX) has been implemented and applied in a previous work (Cocchini F, Nobile MR. Rheol Acta 42:232-242, 2003). It is based on the elegant relationship between the relaxation spectrum and the MWD function proposed by Thimm W, Friedrich C, Marth M. J Rheol 43: 1663-1672 (1999). In the present paper, such a methodology has been generalized to properly account for sharp MWDs, in particular, nearly monodisperse or blends of nearly monodisperse polymer samples. The generalized relationship has been verified and calibrated using the BSW kernel (Baumgaertel M, Schausberger A, Winter HH. Rheol Acta 29: [400][401][402][403][404][405][406][407][408] 1990) to describe the rheological behavior of some Polystyrene samples from the literature, in terms of the known MWD. Then, it has been successfully applied to the inversion problem for a wider set of samples, with both broad and sharp distributions. The Rouse contribution at high frequencies and the accelerating effect on the relaxation times due to polydispersion have been also addressed.