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M I Beltran - One of the best experts on this subject based on the ideXlab platform.
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Study of the processability of commercial PVC Plastisols by rheology
Journal of Vinyl & Additive Technology, 1999Co-Authors: J.c. García-quesada, Antonio Marcilla, M I BeltranAbstract:A qualitative model that satisfactorily explains the rheological behavior of PVC Plastisols during gelation and fusion is shown. Several industrial production cases have been analyzed, and the rheological characterization of the corresponding Plastisols during gelation and fusion processes has proved to be a valuable technique to improve the knowledge and understanding of the industrial rotomolding process.
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The effect of adding processed PVC on the rheology of PVC Plastisols
Polymer, 1998Co-Authors: J C Garcia, Antonio Marcilla, M I BeltranAbstract:In this paper the possibility of recycling the PVC resulting from the rotational moulding of Plastisols is studied. Parts of processed PVC were ground with liquid nitrogen into four fractions of different sizes which were added to a plastisol at different concentrations. A study of the influence of the amount and size of the recycled PVC in the viscosity of the plastisol and in the gelation and fusion processes was carried out. Furthermore, samples were taken at different temperatures and observed by SEM (scanning electron microscopy). Results obtained for Plastisols with the recycled PVC show a marked increase in the viscosity and moduli reached during gelation with time, which are more marked as the amount of recycled PVC increase and the particle size decrease. However, Plastisols including recycled PVC show and adequate processability if they are used immediately after their preparation.
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PVC Plastisols decomposition by FT-IR spectroscopy
European Polymer Journal, 1997Co-Authors: M I Beltran, Antonio MarcillaAbstract:A specially designed cell, as described in previous papers, has been used to study the dynamic in situ decomposition of PVC Plastisols by FT-IR. The FT-IR spectra provides a new point of view into the intricate problem of the effect of the plasticizers (compatibility and concentration) in the PVC decomposition. A qualitative description of the changes observed in the Plastisols spectra is presented. Firstly, the bands due to the plasticizer disappear at temperatures in good accordance with those observed for the plasticizer evaporation in the thermogravimetric decomposition of the PVC plastisol. The plasticizer evaporation leads to a spectrum very similar to that obtained when the PVC is alone at the same temperature. After plasticizer evaporation changes observed in Plastisols decomposition are similar to those previously reported with respect to resins decomposition.
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study of the flow properties and the ageing process in pvc Plastisols from commercial pvc resins
European Polymer Journal, 1997Co-Authors: Antonio Marcilla, J C Garcia, M I BeltranAbstract:The influence of the particle size distribution and the molecular weight distribution in the flow properties and ageing process of commercial PVC Plastisols have been studied. An accelerated method to study the interactions between the resin and the plasticizer during the ageing process of the Plastisols has been suggested.
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pvc plasticizer interactions during the thermal decomposition of pvc Plastisols influence of the type of plastizicer and resin
Polymer Degradation and Stability, 1996Co-Authors: Antonio Marcilla, M I BeltranAbstract:The effect of the type of plasticizer and resin on the thermal decomposition of PVC Plastisols has been studied by thermogravimetric analysis. Eight plasticizers of different solvent power and ten commercial resins were employed. The shape of the thermograms of the Plastisols is strongly influenced by the behaviour of their components. When the plasticizer is in the plastisol, its evolution suffers a delay as compared to when the plasticizer is alone. This behaviour is a consequence of the interactions resulting between the plasticizer and the resin prior to the decomposition process. In the same way, the resin decomposes at lower temperatures when it is in the plastisol. Both effects, the delay in the evolution of the plasticizer and the advance in the decomposition of the resin, are more marked for the more compatible plasticizers. For the more compatible plasticizers, a splitting of the peak corresponding to the resin into two differentiated peaks can be observed in the derivative curve. The first peak has been ascribed to a part of the PVC more susceptible to the plasticizer (i.e. plasticized PVC), while the second probably proceeds from a part of the PVC which suffers less interaction with the plasticizer.
Alfonso Jiménez - One of the best experts on this subject based on the ideXlab platform.
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Characterization of resol resins modified by the addition of PVC Plastisols
Polymer International, 2004Co-Authors: Liliana Beatriz Manfredi, Alfonso Jiménez, Analía VázquezAbstract:Plastisols, which are a blend of poly(vinyl chloride) resin and a plasticizer (DEHP), were used as a toughening agent of a resol resin in order to improve the mechanical properties. It was not possible to formulate resol blends by adding more than 10 % of plastisol owing to a lack of apparent homogeneity in the systems, which also showed many air bubbles. The relationship between dynamic mechanical, mechanical and thermal properties and the amount of plastisol added was studied. It was determined from the infrared spectroscopy and dynamic mechanical results that the resol-plastisol blends seem to be formed by a reaction between the phenol and PVC giving a higher crosslinked structure. An improvement in the thermal resistance of the blends at lower temperatures was observed with an increase in the percentage of plastisol. Flexural analysis showed the elastic behaviour of the systems. However, it was not possible to observe the effect of the plasticizer (DEHP) owing to the low quantity of plastisol that was added to the resol. 2004 Society of Chemical Industry
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formulation and mechanical characterization of pvc Plastisols based on low toxicity additives
Journal of Applied Polymer Science, 2001Co-Authors: Alfonso Jiménez, A. Iannoni, J Lopez, J M KennyAbstract:New formulations of Plastisols based on low-toxicity plasticizers were proposed and characterized. Traditional phthalate plasticizers were replaced in the Plastisols studied in this research by polymeric plasticizers (i.e., saturated polyesters), produced by the reaction of a diol and a carboxylic acid. The main drawback for the use of these plasticizers in formulations of PVC Plastisols is a significant increase of the paste viscosity, which decreases their processability; thus, the use of additional additives to reduce viscosity is recommended. This study also includes the optimization of the processing conditions (cure temperature and time) of the proposed Plastisols: complete cure was obtained at 140°C and 10 min. It is reported that the final properties of Plastisols are very sensitive with respect to the processing conditions; in fact, insufficient plasticization or degradation can affect the material when processed out of the optimum conditions. The influence of the plasticizer concentration on mechanical and optical properties, such as tensile strength, hardness, brightness, and the like, is also reported. In summary, the proposed Plastisols, with low-toxicity plasticizers, offer a valid alternative to traditional PVC Plastisols based on phthalate plasticizers. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1881–1890, 2001
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thermal degradation of poly vinyl chloride Plastisols based on low migration polymeric plasticizers
Polymer Degradation and Stability, 2001Co-Authors: Alfonso Jiménez, Luigi Torre, J M KennyAbstract:The analysis of the thermal degradation of poly(vinyl chloride) (PVC) Plastisols formulated with low-toxicity polymeric plasticizers is reported. Dynamic and isothermal thermogravimetric analyses are applied to study the behavior of these materials at high temperatures and to evaluate their degradation kinetics. The results used for the optimization of the processing conditions, in particular the cure time and temperature, to maximize the thermal stability of the plastisol. The optimum plasticizer concentration is also determined. TGA results have been used to determine the parameters of the degradation kinetic model using Friedman and Horowitz methods. A comparison with the thermal behavior of traditional Plastisols normally employed in industrial applications is reported.
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Kinetic Modeling of the Thermal Degradation of Stabilized PVC Plastisols
Journal of Thermal Analysis and Calorimetry, 2000Co-Authors: Alfonso Jiménez, A. Iannoni, Luigi Torre, Jose Maria KennyAbstract:Thermogravimetric analysis (TG) was used in this work to study the degradation kinetics of industrial PVC Plastisols. In order to model the pyrolitic degradation of Plastisols in nitrogen, a kinetic model based on phenomenological considerations was developed. Two different processes were observed during the first degradation stage. The model parameters, such as activation energies and pseudo orders of reaction, were calculated using a non-linear regression analysis. The model developed was able to describe the degradation behaviour both in isothermal and in dynamic modes. The results of such analysis were applied to obtain long-term data from short-term experiments as an engineering approach to evaluate the thermal resistance of Plastisols.
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Kinetic analysis of the thermal degradation of PVC Plastisols
Journal of Applied Polymer Science, 1999Co-Authors: Alfonso Jiménez, Juan Carlos Cortés López, Luigi Torre, Jose Maria KennyAbstract:The thermal degradation of plasticized polyvinyl chloride (plastisol) is reported here. Plastisols used in the present work were prepared with the plasticizer diethylhexyl phthalate in different proportions. Thermogravimetric analysis has been applied to study the behavior of Plastisols at high temperatures and to evaluate their degradation kinetics. Several tests were carried out at different heating rates and the variation of the degree of reaction with time and temperature was calculated. The influence of the heating rate in dynamic measurements (5- 40°C/min) on kinetic pa- rameters, such as activation energies and reaction orders, has also been studied. These parameters were calculated from dynamic thermogravimetric analysis tests using Friedman analysis and a kinetic model for the degradation of poly(vinyl chloride) and Plastisols has been then developed. The obtained model was able to simulate the thermal degradation process of Plastisols in dynamic conditions and was used to evaluate the effects of additives in the degradation. The results of this study can be used to optimize the concentration of plasticizers and stabilizers in poly(vinyl chloride) formulations. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 1069 -1079, 1999
Antonio Marcilla - One of the best experts on this subject based on the ideXlab platform.
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extensional viscosity measurements and characterization of poly vinyl chloride co vinyl acetate Plastisols and foams
Journal of Applied Polymer Science, 2013Co-Authors: Agnes Zoller, Antonio MarcillaAbstract:The foaming of PVC-VA [Poly (vinyl chloride-co-vinyl acetate)] Plastisols is a complex combination of processes involving the simultaneous curing of the paste with the evolution of gases caused by the decomposition of the chemical blowing agent. The extensional viscosity is a fundamental characteristic of the material, responsible for the behavior of the system when undergoing the extensional stress produced by the released gases. Nevertheless, such changes have not been considered to the same extent as the complex viscosity evolution or the thermal processes suffered by PVC-VA Plastisols. The objective of the present work is to study the extensional viscosity of the PVC-VA Plastisols prepared with three plasticizers of similar structure, but with different curing and rheological behavior in order to investigate its influence on the quality of the foams obtained. Extensional viscosity measurements under forced prestretch conditions revealed that depending on the structure and consequently on the compatibility of the plasticizer used, each plastisol develops its properties and structure accordingly. DINCH plasticizer (Diisononyl cyclohexane-1,2-dicarboxylate presenting alicyclic ring) seems to be the less compatible compared with the other two studied (both presenting aromatic rings) according to its behavior during the curing and foaming processes and may not be able to withstand the pressure evolved by the released gases during the foaming process yielding foams of poorer quality. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
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Study of the processability of commercial PVC Plastisols by rheology
Journal of Vinyl & Additive Technology, 1999Co-Authors: J.c. García-quesada, Antonio Marcilla, M I BeltranAbstract:A qualitative model that satisfactorily explains the rheological behavior of PVC Plastisols during gelation and fusion is shown. Several industrial production cases have been analyzed, and the rheological characterization of the corresponding Plastisols during gelation and fusion processes has proved to be a valuable technique to improve the knowledge and understanding of the industrial rotomolding process.
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Rheological study of the influence of the plasticizer concentration in the gelation and fusion processes of PVC Plastisols
Polymer, 1998Co-Authors: J C Garcia, Antonio MarcillaAbstract:The influence of the type of plasticizer and its concentration on the rheological behaviour of Plastisols made from several commercial resins during the gelation and fusion processes has been studied. The use of different concentrations of plasticizers as well as plasticizers with different compatibilities has allowed the observation of relevant differences in the behaviour of the elastic and viscous moduli in Plastisols with low concentration of plasticizer as well as in Plastisols prepared with plasticizers having higher compatibility with PVC. In addition, scanning electron microscopy has been used in order to obtain a better understanding of the gelation and fusion processes.
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The effect of adding processed PVC on the rheology of PVC Plastisols
Polymer, 1998Co-Authors: J C Garcia, Antonio Marcilla, M I BeltranAbstract:In this paper the possibility of recycling the PVC resulting from the rotational moulding of Plastisols is studied. Parts of processed PVC were ground with liquid nitrogen into four fractions of different sizes which were added to a plastisol at different concentrations. A study of the influence of the amount and size of the recycled PVC in the viscosity of the plastisol and in the gelation and fusion processes was carried out. Furthermore, samples were taken at different temperatures and observed by SEM (scanning electron microscopy). Results obtained for Plastisols with the recycled PVC show a marked increase in the viscosity and moduli reached during gelation with time, which are more marked as the amount of recycled PVC increase and the particle size decrease. However, Plastisols including recycled PVC show and adequate processability if they are used immediately after their preparation.
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PVC Plastisols decomposition by FT-IR spectroscopy
European Polymer Journal, 1997Co-Authors: M I Beltran, Antonio MarcillaAbstract:A specially designed cell, as described in previous papers, has been used to study the dynamic in situ decomposition of PVC Plastisols by FT-IR. The FT-IR spectra provides a new point of view into the intricate problem of the effect of the plasticizers (compatibility and concentration) in the PVC decomposition. A qualitative description of the changes observed in the Plastisols spectra is presented. Firstly, the bands due to the plasticizer disappear at temperatures in good accordance with those observed for the plasticizer evaporation in the thermogravimetric decomposition of the PVC plastisol. The plasticizer evaporation leads to a spectrum very similar to that obtained when the PVC is alone at the same temperature. After plasticizer evaporation changes observed in Plastisols decomposition are similar to those previously reported with respect to resins decomposition.
Herminio C De Sousa - One of the best experts on this subject based on the ideXlab platform.
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effects of poly vinyl chloride morphological properties on the rheology aging of Plastisols and on the thermal leaching properties of films formulated using nonconventional plasticizers
Industrial & Engineering Chemistry Research, 2018Co-Authors: Sofia Marceneiro, Irene Lobo, Isabel Dias, Ana M.a. Dias, Graca M Rasteiro, Elizabete Pinho, Rafael Alves, Herminio C De SousaAbstract:The efficiency of poly(vinyl chloride) (PVC) plasticization depends predominantly on the strength of PVC–plasticizer interactions, which ultimately depends not only on the intrinsic physicochemical properties of the plasticizer but also those of the polymer. The aim of this work was to study the influence of the morphological properties of different PVC grades (two emulsion (with different K values) and one microsuspension grades) and of nonconventional greener plasticizers on the rheological/aging properties of PVC-based Plastisols and on the thermal and plasticizer leaching properties of films obtained from those Plastisols. Commercially available castor oil based CITROFOL AHII and GRINDSTED SOFT-N-SAFE were employed as plasticizers, and the phosphonium-based ionic liquid (trihexyl(tetradecyl)phosphonium bistriflamide ([P6,6,6,14][Tf2N]) as a coplasticizer. Plastisols formulated with the conventional plasticizer di-isodecyl phthalate (DIDP) were also prepared for comparison. Obtained results showed that...
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Effects of Poly(vinyl chloride) Morphological Properties on the Rheology/Aging of Plastisols and on the Thermal/Leaching Properties of Films Formulated Using Nonconventional Plasticizers
2018Co-Authors: Sofia Marceneiro, Irene Lobo, Isabel Dias, Ana M.a. Dias, Graca M Rasteiro, Elizabete Pinho, Rafael Alves, Herminio C De SousaAbstract:The efficiency of poly(vinyl chloride) (PVC) plasticization depends predominantly on the strength of PVC–plasticizer interactions, which ultimately depends not only on the intrinsic physicochemical properties of the plasticizer but also those of the polymer. The aim of this work was to study the influence of the morphological properties of different PVC grades (two emulsion (with different K values) and one microsuspension grades) and of nonconventional greener plasticizers on the rheological/aging properties of PVC-based Plastisols and on the thermal and plasticizer leaching properties of films obtained from those Plastisols. Commercially available castor oil based CITROFOL AHII and GRINDSTED SOFT-N-SAFE were employed as plasticizers, and the phosphonium-based ionic liquid (trihexyl(tetradecyl)phosphonium bistriflamide ([P6,6,6,14][Tf2N]) as a coplasticizer. Plastisols formulated with the conventional plasticizer di-isodecyl phthalate (DIDP) were also prepared for comparison. Obtained results showed that the highest shear stress and plastisol aging were observed for Plastisols formulated using the lower molecular weight emulsion PVC grade (E70-PVC) and the conventional plasticizer DIDP. The E70-PVC systems formulated using DIDP and citrate-based plasticizer presented a pseudoplastic behavior, while all the other systems presented a Newtonian profile. Lower mixing enthalpies were also calculated for PVC/DIDP systems, indicating more favorable interactions for PVC/phthalate systems over nonconventional plasticizers. The incorporation of [P6,6,6,14][Tf2N] as a coplasticizer significantly decreased the enthalpy of mixing of all the prepared Plastisols, showing that its presence in the formulations may favor PVC/plasticizer interactions. Moreover, PVC films obtained from Plastisols formulated using this ionic liquid presented higher long-term thermal stability due to its negligible vapor pressure that avoids loss during usage
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Effects of Two Phosphonium-Type Ionic Liquids on the Rheological and Thermomechanical Properties of Emulsion Poly(vinyl chloride)-Based Formulations Plasticized with DINP and CITROFOL
2014Co-Authors: Sofia Marceneiro, Irene Lobo, Isabel Dias, Ana M.a. Dias, Graca M Rasteiro, Elizabete Pinho, Herminio C De SousaAbstract:Industrial poly(vinyl chloride) (PVC) Plastisols are often formulated using phthalate plasticizers due to their cost-effectiveness and high compatibility with PVC. However, there is a current need to replace these additives by plasticizers that (i) present reduced migration/leaching and volatilization profiles, (ii) can optimize production processes while maintaining the performance of the final plasticized materials, and (iii) reduce toxicological risks to consumers and to the environment. The main objective of this work was to evaluate the effects of the partial replacement (15 and 30% (w/w)) of two conventional plasticizers (diisononyl phthalate (DINP) and acetyltri-2-ethylhexyl citrate (CITROFOL AHII)) by two low-volatility ionic liquids of the phosphonium-type (trihexyl(tetradecyl) phosphonium dicyanamide and trihexyl(tetradecyl) phosphonium bis(trifluoromethylsulfonyl)imide) on the rheological and thermomechanical properties of an emulsion-grade PVC which is usually employed in the production of automotive industry upholsteries. Rheological profiles and Plastisols’ particle size distributions were monitored over time (up to 14 days) to study the effects of Plastisols aging on the thermal stability and thermomechanical properties of PVC films obtained after gelation of the Plastisols. Obtained results showed that the incorporation of these two phosphonium-type ionic liquids into DINP- and CITROFOL-based PVC Plastisols significantly reduced their viscosities and changed their rheological profiles (from pseudoplastic to near-Newtonian behavior). Plastisols aging had a noticeable impact on the final thermomechanical properties of PVC films plasticized with DINP while no significant effects were observed for films plasticized with CITROFOL. These results are in good agreement with the correspondent time-dependent rheological profiles
E.r. Harrell - One of the best experts on this subject based on the ideXlab platform.
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rheology of pvc plastisol iii analyses of dilatancy and fracture
Journal of Colloid and Interface Science, 2001Co-Authors: N. Nakajima, E.r. HarrellAbstract:Abstract In the preceding paper of this series (N. Nakajima and E. R. Harrell, J. Colloid Interface Sci.238, 116 (2001)), the pseudo-plastic behavior of PVC plastisol was analyzed to explain that the shear rate dependence of viscosity was a result of the formation of immobilized layer. The idea of the immobilized layer was based on the works of R. L. Hoffman (Trans. Soc. Rheol.16, 155 (1972); J. Colloid Interface Sci.46, 491 (1974)), who examined the mechanisms of fracture of PVC Plastisols at high shear rates. In our calculation a particular form of the viscosity–particle concentration relationship by C. W. Johnston and C. H. Brower was used (SPE J.26, 31 (1970)). In this study the above work was extended to the region of dilatancy. The increase of viscosity with the increase of shear rate was explained by the dilatation of the immobilized layer. When the dilatation approached its critical limit, the immobilized layer fractured, creating clusters of particles. The degree of clustering was estimated in terms of the amount of trapped plasticizer within the cluster. The amount of the trapped plasticizer decreased as the clusters were broken up when shear rate was increased.
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rheology of pvc plastisol particle size distribution and viscoelastic properties
Journal of Colloid and Interface Science, 2001Co-Authors: N. Nakajima, E.r. HarrellAbstract:Plastisols of poly(vinyl chloride), PVC, are suspensions of fine particles in plasticizer with about 50% resin volume fraction. Typically, the gross particle size ranges from 15 to 0.2 μm and smaller, where the common practice of spray-drying these resins and subsequent grinding of larger particles dictate the size ranges including agglomerates as well as the primary particles. The plastisol is a pastelike liquid, which may be spread to coat substrates. The coated substrates are heated in an oven to gel and fuse the material for producing uniform, rubbery products. Because the first step of processing is spreading the plastisol on a substrate, rheology at room temperature is obviously important. The material is thixotropic under very low stress. The flow behavior is pseudoplastic and exhibits dilatancy and fracture at high shear rate. This work is concerned with the pseudoplastic behavior but the dynamic mechanical measurements are employed instead of the usual steady-state shear flow measurements. This is because the steady shear may break up agglomerates. The dynamic measurements with small strain-amplitude avoid the break-up of the agglomerates. This is important, because this work is concerned with the effects of the particle size distribution on the material behavior. The frequency dependence of both viscous and elastic behavior is recorded and presented with samples varying in particle size distribution.