Synergistic effect in gamma-irradiated poly(vinyl chloride) hard foils stabilized by plasticizer–stabilizer systems

Changes in transparency and color as well as G_HCl values of hard PVC foils exposed to gamma radiation were investigated while using different amounts of the stabilizers ethylene glycol bis-β-aminocrotonate (I), calcium/zinc laurate + epoxy compounds (II), and magnesium/zinc stearate + sorbitol + epoxy compounds (III), and plasticizers dioctyl phthalate (DOP) (IV), dioctyl sebacate (V), propylene glycol polyadipate + octyl alcohol composition (VI), and diisotridecyl phthalate (VII). A strong synergistic effect was observed in systems containing both plasticizer and stabilizer. Best results were obtained for the I + II + IV, I + II + V, and I + III + V systems.     

Effect of lanthanum cyanurate as novel organic thermal stabilizers for polyvinyl chloride

Lanthanum cyanurate was synthesized by reacting cyanuric acid and lanthanum nitrate at basic condition and was characterized by elemental analysis and Fourier transform infrared spectroscopy. Its application as thermal stabilizer for poly(vinyl chloride) (PVC) was investigated by Congo red test and discoloration test. In comparison with other heat stabilizers, including lanthanum stearate, calcium stearate, and zinc stearate, lanthanum cyanurate exhibits high stabilizing effect with excellent initial color of PVC. The stability time reaches the maximum (80 min) when the percentage of lanthanum cyanurate in PVC is 2.5%. The combination stabilizers (LaC₃N₃O₃/Zn(St)₂ obviously increase the complete discoloration time of PVC in comparison with the stabilizer of Zn(St)₂. The stability time of PVC increases from 14 min (stabilized by zinc stearate) to 26 min (stabilized by LaC₃N₃O₃/Zn(St)₂). LaC₃N₃O₃ also shows a slightly stronger effect on tensile strength of PVC than La(St)₃. Therefore, the LaC₃N₃O₃ can be used to replace La(St)₃ and serve as a costabilizer to improve stabilization efficiency of calcium/zinc stabilizers for PVC. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers     

Solid-phase synthesis,reaction mechanism of biomass glycerol metal chelates and its thermal stability property for polyvinyl chloride

To explore the simple preparation method of glycerol metal chelates and effectively expand the application field of glycerol metal chelates and biomass glycerol, the micro-nanopowders such as glycerin zinc (Gly-Zn), and glycerin bismuth (Gly-Bi) were prepared by the solid-phase reaction, using sodium benzene sulfonate as a catalyst and template. Theoretical calculation of deprotonation reaction energy of glycerol and zinc chloride, bismuth nitrate was performed with the framework of DFT, and their structures were characterized by X-ray diffraction, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscope and X-ray photoelectron spectroscopy. The thermal stability of Gly-Zn and Gly-Bi for polyvinyl chloride (PVC) is discussed by TG. The results show that the deprotonation reaction of glycerol with zinc chloride or bismuth nitrate mainly occurs in the dehydrogen of secondary hydroxyl ( O_secH) and primary hydroxyl ( O_primH) of glycerol molecules, and the H of  O_secH is more active than that of the  O_primH. The obtained Gly-Zn and Gly-Bi have good micromorphology with the rod-like and bar-like respectively. Applied them as thermal stabilizers to PVC processing, the reaction kinetic constant (k, s⁻¹) is an order of k_PVC > k_PVC/Gly-Zn > k_PVC/Gly-Bi. After the additions of 10% Gly-Zn and 10% Gly-Bi, the thermal stability time (min) of PVC, PVC/Gly-Zn and PVC/Gly-Bi is 45, 54.43 and 71.47, respectively.     

Intercalated hydrotalcite‐like materials and their application as thermal stabilizers in poly(vinyl chloride)

The preparation of hydrotalcites with traditional materials is often based on the corresponding salts and alkali solutions. In this study, to facilitate industrial synthesis and take advantage of the lower cost during the process, a Ca–Al–HPO₃–layered double hydroxide (LDH) was directly synthesized with calcium hydroxide, aluminum hydroxide, and sodium phosphite powders. X‐ray diffraction, Fourier transform infrared, and scanning electron microscopy analyses confirmed the successful synthesis of the phosphite‐intercalated hydrotalcite. Compared with Ca–Al–CO₃–LDH, Ca–Al–HPO₃–LDH enhanced the heat stability of poly(vinyl chloride) (PVC) in terms of both short‐term and long‐term stability because phosphite replaced the allyl chloride and reacted with the conjugated double bonds in PVC; this was deduced through a thermal aging test. The composites of Ca–Al–HPO₃–LDH, zinc stearate, and calcium stearate had a synergetic effect when added to PVC and exhibited excellent thermal stability. In addition, the phosphite reacted with ZnCl₂ in case of the phenomenon of zinc burning. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44896.     

Effect of lanthanide (La(III))‐containing ionomer on thermal stabilization of poly(vinyl chloride)

A type of lanthanide (La(III))‐containing ionomer based on acrylate processing aid (ACR) for poly (vinyl chloride) (PVC) was synthesized, and influence of the ionomer on thermal stabilization of PVC was investigated with visual color comparison and Congo red methods. Results revealed that the ionomer with a suitable La(III) content behaved as a good costabilizer to PVC. It was able to extend static stabilization time of PVC and postpone “zinc burning.” The stabilizing efficiency of the ionomer to PVC depended on ion content, which was discussed in terms of Eisenberg–Hird–Moore model. Moreover, Fourier transform infrared test verified that this ionomer can react with zinc stearate (ZnSt₂) to form some new structures, which is responsible for postponing “zinc burning.” The ionomer and epoxidized soybean oil exhibited a synergistic effect on the stabilizing efficiency of calcium stearate (CaSt₂)/ZnSt₂ stabilizer to PVC compounds. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Investigation of lanthanum trioxypurine with zinc stearate and pentaerythritol as complex thermal stabilizers for poly(vinyl chloride)

Lanthanum trioxypurine (LaTr) was triumphantly synthesized by reacting trioxypurine and lanthanum nitrate at neutral condition and was characterized by elemental analysis, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The thermal stability effect of LaTr with its assistant thermal stabilizers about zinc stearate (ZnSt₂) and pentaerythritol (Pe) on poly(vinyl chloride) (PVC) was investigated by Congo red test, discoloration test, UV–vis spectroscopy test, and thermal decomposition kinetics. The results showed that the addition of LaTr as thermal stabilizer could significantly enhance static stability time and long‐term stability of PVC. It could be mainly attributed to the anions in the structure of LaTr, could efficiently absorb the hydrogen chloride released by PVC, and have ability to replace unstable chlorine atoms on structure of PVC. Moreover, the mixing of LaTr, Pe, and ZnSt₂ could reveal an excellent synergistic effect and both promote the initial color and the long‐term thermal stability of PVC. The thermal stability of PVC reached the optimal state when the ratio of LaTr/Pe/ZnSt₂ was 1.8/0.6/0.6. In addition, compared with the reaction energy E_a and UV–vis spectroscopy test's result of PVC samples, the order of PVC's thermal stability was PVC/LaTr/Pe/ZnSt₂ > PVC/LaTr/Pe > PVC/LaTr. The result was further ascertained that LaTr/Pe/ZnSt₂ showed excellent synergistic effect and could be used as an excellent complex thermal stabilizer for PVC. J. VINYL ADDIT. TECHNOL., 25:347–358, 2019. © 2019 Society of Plastics Engineers     

Tensile properties,thermal stability,and the mechanism of PVC stabilized with zinc and calcium oxolinic complexes

Two novel thermal stabilizers, zinc and calcium oxolinic complexes (Zn(Oxo)₂ and Ca(Oxo)₂), with superior tensile properties and notable thermal stability effect for polyvinyl chloride (PVC) are reported here. The complexes are synthesized without any organic solvents, and the structures are confirmed as Zn(C₁₃H₁₀NO₅)₂·H₂O and Ca(C₁₃H₁₀NO₅)₂·3H₂O by Fourier transform infrared spectroscopy, thermogravimetric analysis, X-ray fluorescence spectrometry, and elemental analysis. The PVC samples stabilized with the complexes show superior tensile strength and elongation at break compared with zinc and calcium stearates by tensile test. The results of Congo red test, dehydrochlorination test, and discoloration test show that: (1) Zn(Oxo)₂ is better than zinc stearate as thermal stabilizer for PVC; (2) Zn(Oxo)₂ and Ca(Oxo)₂ show notable synergistic effect with calcium stearate and zinc norfloxacin respectively. The mechanism of the superior tensile properties and notable thermal stability effect is due to the ability of the complexes to absorbing HCl and reacting with PVC chains, which result in the special chain extension of PVC and the delay of autocatalytic effect and zipper-like dehydrochlorination. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47004.     

N′‐acryloyl benzhydrazide as a thermal stabilizer for rigid poly(vinyl chloride)

N′‐Acryloyl benzhydrazide (ABH) was examined as a thermal stabilizer and costabilizer for rigid poly(vinyl chloride) (PVC) in air at 180°C. Its high stabilizing efficiency was shown by its high thermal stability value (T_s) when compared with those of two common reference stabilizers used industrially, dibasic lead carbonate (DBLC) and a calcium–zinc soap. Blending this organic stabilizer with the reference stabilizers in different ratios had synergistic effects on both the thermal stability and the extent of discoloration of the PVC. The Ni²⁺ complex of ABH gave better thermal stability and lesser discoloration than the parent organic stabilizer. Also, blending that complex with DBLC in different ratios gave better stability and lower discoloration. Thermogravimetric analysis confirmed the improved stability of PVC in the presence of the ABH stabilizer. J. VINYL ADDIT. TECHNOL., 2008. © 2008 Society of Plastics Engineers.     

Lanthanum histidine with pentaerythritol and zinc stearate as thermal stabilizers for poly(vinyl chloride)

Lanthanum histidine [La(His)₂·(NO₃)·2H₂O or La(His)₂] was synthesized via the reaction of histidine and lanthanum nitrate, and it was investigated as a stabilizer for poly(vinyl chloride) (PVC). The results show that La(His)₂ exhibited a stabilizing effect on PVC as a long‐term stabilizer because it prolonged the stability time of PVC to 76 min, which was about 24 times longer than the stability time of the pure PVC. The stabilizing effect of La(His)₂ as a costabilizer with pentaerythritol (Pe) and zinc stearate (ZnSt₂) was also studied. The results show that the use of La(His)₂ with Pe or Pe/ZnSt₂ improved the stability time of PVC. La(His)₂/Pe/ZnSt₂ provided PVC with a good initial color and long‐term stability, and when it was prepared at mass ratios of 0.8:2.4:0.8 and 1.6:1.6:0.8, the stability times of PVC were improved to 86 and 88 min, respectively. As a nontoxic stabilizer, La(His)₂/Pe/ZnSt₂ has the potential to replace the toxic stabilizers widely used in PVC manufacturing. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42878.     

Influence of acrylate processing aid‐based ionomer containing lanthanide (La(III)) ion on thermal stability,fusion, transparency and mechanical properties of rigid poly(vinyl chloride)

An acrylate processing aid (ACR)‐based ionomer containing lanthanide (La(III)) ion was synthesized and the influences of the ionomer on thermal stability, fusion time, transparency and tensile properties of rigid poly(vinyl chloride) (PVC) were investigated. Results revealed that the ionomer with a suitable La(III) content behaved as a good stabilizer as well as processing aid to the rigid PVC product. The ionomer could accelerate fusion of PVC much more quickly than ACR because of the strong interaction between La(III) carboxylate and PVC. Moreover, it exhibited a stabilizing efficiency comparable to lanthanum and calcium stearates (LaSt₃ and CaSt₂). The composite stabilizer of ionomer/zinc stearate (ZnSt₂) exhibited an ability to improve initial discoloration better than LaSt₃/ZnSt₂ and CaSt₂/ZnSt₂ because the ionomer could form a complex with ZnSt₂ much more slowly than LaSt₃ and CaSt₂. The compounds stabilized using ionomer/ZnSt₂ exhibited a transparency comparable to those stabilized using organotin or liquid barium/zinc stabilizers, which was much better than those stabilized using LaSt₃/ZnSt₂ and CaSt₂/ZnSt₂. Copyright © 2011 Society of Chemical Industry     

Improvement of the processability and thermal stability of poly(vinyl chloride) with 5,6-diamino-1,3-dimethyluracil

Uracil derivatives are potential nontoxic thermal stabilizers of poly(vinyl chloride) (PVC) and have a better stabilization effect. 5,6-diamino-1,3-dimethyluracil (DDU) was investigated as a thermal stabilizer for PVC. The stabilization effect of DDU was measured by thermogravimetric analysis, thermal aging test, and recording the time of the color change of the Congo red paper (Congo red test). Meanwhile, the processability of PVC stabilized by DDU was investigated through dynamic performance test. The results showed a better stabilizing effect compared with calcium stearate (CaSt₂) and zinc stearate (ZnSt₂). To explain the stabilization of DDU, the probable mechanism was suggested that DDU absorbed and chemically bonded with hydrogen chloride. Therefore, DDU could be used as a thermal stabilizer of PVC.     

Diffusion of vinyl chloride from PVC packaging material into food simulating solvents

Two models are used to describe vinyl chloride monomer (VCM) diffusion from poly(vinyl chloride) (PVC) packages to food simulating solvents. It was found that when the initial solid concentration in a PVC package is 0,35 ppm: (a) For poor solvents such as water and oils, VCM concentration in the solvent, C_l, theoretically will not exceed 20 ppb. (b) For strong solvents, the volume ratio of package solid/solvent should not exceed 0.1 in order to keep (C_l)_max below 20 ppb. (c) It was demonstrated that thickness can be adjusted to give a C_l = 20 ppb at the time equal to the shelf-life of the package. The method can also be used to calculate the initial concentration of VCM in a package which will give a proposed level of maximum C_l when the solvent and package geometry are fixed. VCM diffusion from PVC pressure pipe to pipe fluids was similarly analyzed.     

Influence of nano‐CeO2 as Co‐stabilizer on the thermal stabilization efficiency of novel calcium/Zinc soap stabilizers for poly(vinyl chloride)

The novel organic calcium (Ca)/zinc (Zn) stabilizer of poly(vinyl chloride) (PVC) was synthesized from poly (zinc methylacrylate) and Ca adipate. The influences of Zn/Ca soap weight ratios and nano‐CeO₂ as co‐stabilizer on the thermal stability of PVC were investigated. Congo red testing, thermogravimetric analysis, dynamic rheology, and dynamic mechanical analysis of the mixtures were performed. The results show that the novel stabilizer has good stabilization efficiency on PVC. When 5 phr (parts by weight per hundred parts of resin) of novel stabilizer (weight ratio of Zn/Ca soap is 6/4) in 100 phr of PVC is used as stabilizer, the Congo red time can reach 192 min, which is 131 min longer than 5 phr of the mixture of 3 phr of Zn stearate and 2 phr of Ca stearate as stabilizer. If 3 phr of mixture of Zn methylacrylate with Ca adipate (weight ratio of Zn/Ca soap is 4/6) and 2 phr of nano‐CeO₂ are used as co‐stabilizers, the Congo red time is 205 min. The combination of nano‐CeO₂ with Ca/Zn soap stabilizer shows an obvious improvement for the thermal stability of the PVC. J. VINYL ADDIT. TECHNOL., 20:243–249, 2014. © 2014 Society of Plastics Engineers     

Effect of zinc maleate/zinc oxide complex on thermal stability of poly(vinyl chloride)

In this study, zinc maleate (ZnMA) and zinc oxide (ZnO) complex (ZnMA/ZnO) was prepared by two methods, namely, by the reaction of maleic acid (MAH) with excess ZnO in aqueous solution and by direct mixing of ZnMA and ZnO at 180°C. The chemical structure of the complex was analyzed by X‐ray diffraction, thermogravimetric analysis (TGA), and Fourier transform infrared (FTIR) spectroscopy. The thermal stabilizing effect of the complex on poly(vinyl chloride) (PVC) was evaluated through static and dynamic stability methods. Compared to calcium and zinc soaps and ZnMA alone, the complex exhibited better thermal stabilizing effect on PVC. The stabilization mechanism was also investigated by ultraviolet–visible spectrometer, FTIR, TGA, and gel content analysis. The results indicated that the complex which involved the replacement of labile chlorine atoms hindered the formation of conjugated double bonds in PVC chains via Diels–Alder reaction, and ZnMA/ZnO complex also exhibited the ability to absorb hydrogen chloride. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41464.     

Bacterial adhesion to poly(vinyl chloride) films: Effect of chemical modification and water induced surface reconstruction

Escherichia coli (E. coli) and Staphyloccus aureus (S. aureus) bacteria adhesion to pure and modified poly(vinyl chloride) (PVC) was investigated through classical wettability measurements, captive bubble time dependent measurements, and static adhesion tests. Various chemical modifiers were studied, namely 4-mercaptophenol, 4-mercaptobenzylalcohol, 4-methoxybenzenethiol, 2-naphthalenethiol and 4-mercaptopyridine. The surface thermodynamics of the modified PVC films was investigated via the van Oss, Chaudhury and Good (vOCG) theory and an increase in the hydrophilic character was deduced from the increase of the contact angle of the air bubble in water with time of immersion. This is ascribed to a water induced surface reconstruction of the modified PVC surface. E. coli bacteria exhibit a hydrophilic character and strong adhesion, dependence on the nature of the PVC modifier as shown by the remaining attached bacteria. S. aureus which is hydrophobic showed no difference in its adhesion to pure or modified PVC. A slight increase in the adhesion of E. coli is observed with the water induced surface reconstruction. This work highlights the predominance of the hydrophilic/hydrophobic nature over the acid–base in the bacteria/polymer adhesion mechanism. It also provides, through chemical modification of PVC, a nice route to control the micro-organisms' adhesion to biomedical devices.     

Application of metallic phytates to poly(vinyl chloride) as efficient biobased phosphorous flame retardants

Simple, direct precipitation was used to synthesize green, renewable, biobased flame retardants. Copper phytate (Cu–Phyt), zinc phytate, aluminum phytate, and tin phytate (Sn–Phyt) were synthesized. Thermogravimetric analysis performed in N₂ revealed that the metallic phytate (M–Phyt, where M is Cu, Zn, Al, or Sn) salts showed good charring. The limiting oxygen index (LOI), cone calorimetry (CONE) test data, tensile strength, and impact toughness were measured for flexible poly(vinyl chloride) (PVC) containing 15 wt % M–Phyt salts. The PVC/Sn–Phyt LOI rose from 24.9 to 30.3%, and the PVC/Sn–Phyt mechanical properties were on par with those of the pure PVC. The CONE test results indicate that PVC/Cu–Phyt showed the lowest total smoke production (TSP) and peak heat‐release rate (pHRR) among the samples. The TSP and pHRR of PVC/Cu–Phyt were 15.77 m² and 181.77 kW/m², respectively, 62.63 and 44.48% lower than those of the neat PVC. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46601.     

Fracture behavior of poly(vinyl chloride)/methyl methacrylate/butadiene/styrene polymer blends

The fracture mode of poly(vinyl chloride)/methyl methacrylate/butadiene/styrene (PVC/MBS) polymer blends can change from ductile to brittle in accordance with the changes in shape of the test specimen or test conditions. Therefore, the mechanisms of impact energy absorption and the main cause of stress whitening are complicated. The following results on PVC/MBS blends were obtained by carrying out fracture experiments at different test speeds and temperatures:

• (1) The ductile/brittle fracture mode of the PVC and PVC/MBS blends can be explained by σ (the craze initiation stress)/σ_y (the shear yield initiation stress), which depends on the strain rates and temperature.
• (2) The fracture behavior of the PVC/MBS blends can be classified into the following types from the standpoints of fracture mode and whitening degree: Fracture I: ductile fracture without whitening; Fracture II: ductile fracture with whitening; and Fracture III: brittle fracture without whitening.
• (3) The following concepts can be estimated from the measurements of yield stress, specific gravity and SEM, TEM and visual observations. In Fracture I, shear yield occurs mainly. In Fracture II, both shear yield and crazing occur. In Fracture III, deformation of the rubber and local crazing occur.
• (4) The main cause of stress whitening in PVC/MBS blends is light scattering by cavities in the rubber particles.
• (5) In Fracture II, at first, crazes with cavities in the rubber particles occur. Then, shear yield occurs. Finally, crazes are healed by the heat, and only the cavities in the rubber remain.

     

Synergistic combination of metal stearates and β‐diketones with hydrotalcites in poly(vinyl chloride) stabilization

A synergistic effect of synthetic hydrotalcites as long term stabilizer with metal soaps (the mixture of calcium and zinc stearate) and metal acetylacetonates on dehydrochlorination of PVC has been studied. A proper balance between color stabilization and HCl scavenging capacity has been obtained. Hydrotalcite was prepared by hydrothermal treatment and characterized by EDX, XRD, FTIR, TGA, and SEM techniques. The material is reasonably crystalline and suggests a relatively well ordered sheet arrangement with crystallite size 24.87 nm. The interlayer water content was calculated from the TGA curves and the suggested formula is Mg_0.76 Al_0.24(OH)₂(CO₃)_0.12·0.5H₂O. Synergism in PVC stabilization has been studied by measuring the HCl evolution during the processing at 180°C. Oven aging method was used to study the color stabilization at higher temperature. PVC sheet with different formulation was prepared using Labcoater and subjected to oven for different time interval. The color development (polyene formation) on oven ageing was recorded using UV–visible spectroscopy. UV–visible studies shows that an average sized polyene gives pale yellow color, whereas red or brown color was developed due to long range polyene (n = 10–14) sequences. Hence, the HCl evolution depends on the rate of dehydrochlorination but color depends on the kind of polyene formed. Mechanism of stabilization suggests that adsorption and ion exchange, both phenomenon, are responsible for hydrotalcites as long term stabilizers. The acetylacetonate complex too substitute allylic chlorides and inhibit formation of long polyene responsible for darkening. A clear effect of synergism has been observed. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synergistic effect of acetonedicarboxylic acid diethyl ester and calcium/zinc stearates on poly(vinyl chloride) thermal stability

Acetonedicarboxylic acid diethyl ester (AADE) is obtained by the interaction of ethanol with acetonedicarboxylic acid that is prepared from anhydrous citric acid. The thermal stabilizing effect of calcium and zinc stearates (CaSt₂/ZnSt₂) combined with AADE on poly (vinyl chloride) (PVC) is evaluated by the Congo red test, conductivity test, thermal aging test, and thermogravimetric analysis. The results of thermal stability tests show that the addition of AADE can improve not only the thermal stability but also the color stability of PVC. The improvement in stabilizing effectiveness is ascribed to the synergistic effect between CaSt₂/ZnSt₂ and AADE. The thermal stability mechanism of AADE is also under discussion with the help of quantum chemical calculations. The results of quantum chemical calculations indicate that, besides having the ability to form complexes with zinc ion, AADE has an evident tendency to replace the allyl chloride of the PVC. The results of the thermal aging test and quantum chemical calculations show that the thermal stabilizing effectiveness of AADE is higher than that of stearoyl benzoyl methane (β‐Diketones). J. VINYL ADDIT. TECHNOL., 21:228–234, 2015. © 2014 Society of Plastics Engineers     

Plasticizer migration from plasticized into unplasticized poly(vinyl chloride)

There exist important industrial applications, such as hoses or plastic windows, dealing with closely combining plasticized and rigid poly(vinyl chloride). Nevertheless, migration of plasticizer causes severe variation of the mechanical performance of the end-products. This work comprises an effort to investigate and understand these phenomena, also as an extension of previous work of ours in migration to liquid environments. The common system plasticized PVC/dioctylphthalate/unplasticized PVC was studied under two-sided diffusion conditions, i.e., from a thin sheet of plasticized sheet. The whole assembly was placed between two glass plates and then was held in an oven at 64°C to simulate accelerated test conditions. Some pressure was also applied to ensure perfect contact between the plastic sheets. Three different levels of initial plasticizer concentration (48, 66, and 100 phr) have been considered for a period of about five months, until equilibrium was reached. During this period the migration process was monitored by weight changes. Plots of M_t/M_∞ vs. t^½, where M_∞ the amount migrated at equilibrium and M_t the amount lost at time t, resulted in evident linear relationship. Therefore, it was proved that the Fick's law approximation for short times can be used to describe the migration kinetics for this solid/solid system. On the other hand, macroscopic observations revealed that no plasticizer was accumulated at the interface, i.e. all plasticizer leaving the plasticized sheet entered the rigid ones. Finally, it seems that the controlling stage is the diffusion inside plasticized PVC while possible annealing of the plasticized polymer structure cannot be excluded.