Patrice Dole - Academia.edu (original) (raw)
Papers by Patrice Dole
Radiation Physics and Chemistry, 2012
The present paper focuses on the effects of electron beam (EB) irradiation on thermoplastic mater... more The present paper focuses on the effects of electron beam (EB) irradiation on thermoplastic materials based on destructurized starch including glycerol and water as plasticizers to assess the potentiality of cinnamyl alcohol as reactive additive capable of counterbalancing the degradation of the polysaccharide by inducing interchain covalent linkages. The tensile properties at break of test specimens of controlled composition submitted
Journal of Applied Polymer Science, 2001
ABSTRACT
Journal of Applied Polymer Science, 2012
Journal of Applied Polymer Science, 2006
Journal of Agricultural and Food Chemistry, 2008
The migration of additives from food packaging to food stuffs is kinetically governed by the diff... more The migration of additives from food packaging to food stuffs is kinetically governed by the diffusion coefficient (D) of the additive within the polymer. Food safety authorities have recently allowed the use of mathematical models to predict D, with the additive molecular weight as a single entry parameter. Such models require experimental values to feed the databases, but these values are often scattered. To deal with this issue, a fluorescent chemically homologous series of model additives was synthesized with molecular weights (MW) ranging from 236 g.mol (-1) to 1120 g.mol (-1). This set was then used to collect diffusion coefficients D through confocal fluorescence recovery after photobleaching (FRAP). This microscopic technique allows in situ packaging micro migration tests. The FRAP method was tested against results from the literature before being applied to two different model polystyrenes in a preliminary study to investigate the relationship D = f(MW). Our intermediate objective was to compare various experimental D = f(MW) from our method with predictions from other mathematical or semiempirical models.
Journal of Agricultural and Food Chemistry, 2010
Food safety authorities have already allowed the use of mathematical models to predict diffusion ... more Food safety authorities have already allowed the use of mathematical models to predict diffusion from plastic food contact materials. These models use the molecular weight of the migrant as a cornerstone parameter that describes the contribution of the migrant to the diffusion process. In this work, the dependence of the diffusion coefficient on the migrant size was examined through fluorescence recovery after photobleaching (FRAP). A model migrant series of fluorescent probes was used, covering a wide molecular weight range. The advantage and originality of the tested migrant series are associated with the fact that the same shape and chemical functionality are maintained regardless of the molecular weight of the migrants. In this way the dependence of the acquired data on parameters other than size is excluded. The same experiments were carried out in dry and hydrated polyamide 6 to evaluate the effect of polymer matrix mobility in the "diffusion-migrant size" relationship. The experimental data were compared to well-known mathematical or semiempirical approaches, verifying that there is a relationship between the diffusion coefficient and the size of the migrant. However, it is demonstrated that this relationship is also affected by the mobility of the polymer matrix, becoming more pronounced as the mobility of the matrix decreases.
Food Chemistry, 2006
The water-binding properties of wheat starch films were studied through the determination of wate... more The water-binding properties of wheat starch films were studied through the determination of water vapour adsorption isotherms at 20°C. Starch films were obtained by casting after mixing native starch at 95°C for 15min with different ratios of plasticizer (glycerol).Unplasticized starch film was found to adsorb less water than native starch granules. The effect of glycerol on water vapour adsorption by
Food Additives & Contaminants: Part A, 2010
Food Additives and Contaminants, 2006
When plastics are collected for recycling, possibly contaminated articles might be recycled into ... more When plastics are collected for recycling, possibly contaminated articles might be recycled into food packaging, and thus the contaminants might subsequently migrate into the food. Multilayer functional barriers may be used to delay and to reduce such migration. The contribution of the work reported here is to establish reference values (at 40 degrees C) of diffusion coefficients and of activation energies to predict the functional barrier efficiency of a broad range of polymers (polyolefins, polystyrene, polyamide, PVC, PET, PVDC, [ethylene vinyl alcohol copolymer], polyacrylonitrile and [ethylene vinyl acetate copolymer]). Diffusion coefficients (D) and activation energies (Ea) were measured and were compiled together with literature data. This allowed identification of new trends for the log D=f(molecular weight) relationships. The slopes were a function of the barrier efficiency of the polymer and temperature. The apparent activation energy of diffusion displayed two domains of variation with molecular weight (M). For low M (gases), there was little variation of Ea. Focusing on larger molecules, high barrier polymers displayed a larger dependence of Ea with M. The apparent activation energy decreased with T. These results suggest a discontinuity between rubbery and glassy polymers.
Carbohydrate Polymers, 2010
The influence of partial beta-amylase dextrinisation on the recrystallisation properties of wheat... more The influence of partial beta-amylase dextrinisation on the recrystallisation properties of wheat starch was monitored by DSC. The melting peak endotherm in the 100–140°C range decreased regularly at increasing degradation levels, and disappeared with the limit dextrin. Mechanical properties of the obtained partial dextrins displayed unusual stress/strain couple value. Dextrinisation leads to an increase of strain at break with retention
Carbohydrate Polymers, 2004
This paper deals with gas transport properties of starch based films. Oxygen permeability of plas... more This paper deals with gas transport properties of starch based films. Oxygen permeability of plasticised starch, octanoated starch, starch–EVOH blend, and PE–starch multilayer was first studied. The best gas barrier properties of starch based films are generally obtained for low water and plasticiser contents.It was then shown that the interesting low permeability of these systems is due to the low
Radiation Physics and Chemistry, 2012
The present paper focuses on the effects of electron beam (EB) irradiation on thermoplastic mater... more The present paper focuses on the effects of electron beam (EB) irradiation on thermoplastic materials based on destructurized starch including glycerol and water as plasticizers to assess the potentiality of cinnamyl alcohol as reactive additive capable of counterbalancing the degradation of the polysaccharide by inducing interchain covalent linkages. The tensile properties at break of test specimens of controlled composition submitted
Journal of Applied Polymer Science, 2001
ABSTRACT
Journal of Applied Polymer Science, 2012
Journal of Applied Polymer Science, 2006
Journal of Agricultural and Food Chemistry, 2008
The migration of additives from food packaging to food stuffs is kinetically governed by the diff... more The migration of additives from food packaging to food stuffs is kinetically governed by the diffusion coefficient (D) of the additive within the polymer. Food safety authorities have recently allowed the use of mathematical models to predict D, with the additive molecular weight as a single entry parameter. Such models require experimental values to feed the databases, but these values are often scattered. To deal with this issue, a fluorescent chemically homologous series of model additives was synthesized with molecular weights (MW) ranging from 236 g.mol (-1) to 1120 g.mol (-1). This set was then used to collect diffusion coefficients D through confocal fluorescence recovery after photobleaching (FRAP). This microscopic technique allows in situ packaging micro migration tests. The FRAP method was tested against results from the literature before being applied to two different model polystyrenes in a preliminary study to investigate the relationship D = f(MW). Our intermediate objective was to compare various experimental D = f(MW) from our method with predictions from other mathematical or semiempirical models.
Journal of Agricultural and Food Chemistry, 2010
Food safety authorities have already allowed the use of mathematical models to predict diffusion ... more Food safety authorities have already allowed the use of mathematical models to predict diffusion from plastic food contact materials. These models use the molecular weight of the migrant as a cornerstone parameter that describes the contribution of the migrant to the diffusion process. In this work, the dependence of the diffusion coefficient on the migrant size was examined through fluorescence recovery after photobleaching (FRAP). A model migrant series of fluorescent probes was used, covering a wide molecular weight range. The advantage and originality of the tested migrant series are associated with the fact that the same shape and chemical functionality are maintained regardless of the molecular weight of the migrants. In this way the dependence of the acquired data on parameters other than size is excluded. The same experiments were carried out in dry and hydrated polyamide 6 to evaluate the effect of polymer matrix mobility in the "diffusion-migrant size" relationship. The experimental data were compared to well-known mathematical or semiempirical approaches, verifying that there is a relationship between the diffusion coefficient and the size of the migrant. However, it is demonstrated that this relationship is also affected by the mobility of the polymer matrix, becoming more pronounced as the mobility of the matrix decreases.
Food Chemistry, 2006
The water-binding properties of wheat starch films were studied through the determination of wate... more The water-binding properties of wheat starch films were studied through the determination of water vapour adsorption isotherms at 20°C. Starch films were obtained by casting after mixing native starch at 95°C for 15min with different ratios of plasticizer (glycerol).Unplasticized starch film was found to adsorb less water than native starch granules. The effect of glycerol on water vapour adsorption by
Food Additives & Contaminants: Part A, 2010
Food Additives and Contaminants, 2006
When plastics are collected for recycling, possibly contaminated articles might be recycled into ... more When plastics are collected for recycling, possibly contaminated articles might be recycled into food packaging, and thus the contaminants might subsequently migrate into the food. Multilayer functional barriers may be used to delay and to reduce such migration. The contribution of the work reported here is to establish reference values (at 40 degrees C) of diffusion coefficients and of activation energies to predict the functional barrier efficiency of a broad range of polymers (polyolefins, polystyrene, polyamide, PVC, PET, PVDC, [ethylene vinyl alcohol copolymer], polyacrylonitrile and [ethylene vinyl acetate copolymer]). Diffusion coefficients (D) and activation energies (Ea) were measured and were compiled together with literature data. This allowed identification of new trends for the log D=f(molecular weight) relationships. The slopes were a function of the barrier efficiency of the polymer and temperature. The apparent activation energy of diffusion displayed two domains of variation with molecular weight (M). For low M (gases), there was little variation of Ea. Focusing on larger molecules, high barrier polymers displayed a larger dependence of Ea with M. The apparent activation energy decreased with T. These results suggest a discontinuity between rubbery and glassy polymers.
Carbohydrate Polymers, 2010
The influence of partial beta-amylase dextrinisation on the recrystallisation properties of wheat... more The influence of partial beta-amylase dextrinisation on the recrystallisation properties of wheat starch was monitored by DSC. The melting peak endotherm in the 100–140°C range decreased regularly at increasing degradation levels, and disappeared with the limit dextrin. Mechanical properties of the obtained partial dextrins displayed unusual stress/strain couple value. Dextrinisation leads to an increase of strain at break with retention
Carbohydrate Polymers, 2004
This paper deals with gas transport properties of starch based films. Oxygen permeability of plas... more This paper deals with gas transport properties of starch based films. Oxygen permeability of plasticised starch, octanoated starch, starch–EVOH blend, and PE–starch multilayer was first studied. The best gas barrier properties of starch based films are generally obtained for low water and plasticiser contents.It was then shown that the interesting low permeability of these systems is due to the low