Plasticized PVC Films Research Articles

PARTITION OF VCM IN PLASTICIZED PVC/FOOD SIMULANT SYSTEMS

Partition of Vinyl Chloride Monomer (VCM) between plasticized PVC films and corn oil and between PVC films and water was studied. A specific procedure with predetermined calibration curves has to be followed in order to obtain reliable and reproducible results. At very low VCM levels, the partition coefficient increased with decrease in monomer concentration indicating a preference of the monomer towards the polymer. In plasticized PVC films, the level of plasticization may affect the residual VCM in the film, the rate and extent of monomer migration from the polymeric matrix, as well as the equilibrium monomer distribution between the PVC and the contacting phase.

Relationship of welding technology to degree of plasticization in the PVC films

AbstractThe influence of the degree of plasticization on optimum heat‐sealing or high‐frequency welding conditions has been studied for plasticized PVC films with different quantities of DOP plasticizer. Two equations were obtained that relate the parameters of the welding process (time and temperature, or time and specific anodic current) with the degree of PVC film plasticization. The equations allow calculation of welding conditions needed to obtain maximum strength of welded joints. One describes the durability of lap joints; the other of T‐joints.

Electrical conductivity of anionic graft copolymers obtained by radiation grafting of 4-vinylpyridine onto poly(vinyl chloride)

The electrical conductivity of the graft copolymers, obtained by direct radiation grafting of 4-vinylpyridine onto pure and plasticized poly(vinyl chloride) PVC films was investigated under various temperatures and applied potentials. The electrical conductivity of such graft copolymers increased as the temperature was elevated, for a given applied potential and degree of grafting. The degree of grafting, the additives in PVC, and the quaternizing agent have an influence on the electrical behaviour of the grafted films. The main feature of the activation energy of the graft copolymers was its very low values and two different activation energies were found for each copolymer based on the applied potential. The values of the activation energy for MeI-quaternized plasticized PVC film were almost twice those for the MeI-quaternized pure one. When using HCl as quaternizing agent, however, values of the activation energy for both grafted pure and plasticized PVC films were almost the same at a given applied potential.

Crosslinked grafted PVC obtained by direct radiation grafting

Direct radition-induced grafting of 4-vinylpyridine onto both pure and plasticized poly(vinyl chloride) has been studied. The effect of grafting conditions such as solvent, monomer concentration, irradiation dose, and inhibitor concentration on the grafting yield was investigated. The grafting process was enhanced by using distilled water as diluent and higher degrees of grafting were obtained as compared with other solvents used (benzene, methanol, and a mixture of methanol and water). The homopolymerization of 4-vinylpyridine was reduced to a minimum using ammonium ferrous sulfate and the suitable optimum concentration of the inhibitor was found to be 0.25 wt %. It was observed that the degrees of grafting onto plasticized PVC were higher than those onto pure one, at constant grafting conditions. The diffusibility of the monomer solution through the trunk polymers enhanced at higher monomer concentrations. The higher the monomer concentration the higher the degrees of grafting obtained. The dependence of the grafting rate on monomer concentration was found to be 0.15 and 0.4 order for the grafting onto pure and plasticized PVC films, respectively. The degree of grafting, at the higher irradiation doses, deviated from linearity and it tends to level off due to the recombination of some of the free radicals without initiating graft polymerization. Gel determination in the grafted films was investigated. The gel content in both grafted extracted pure and plasticized PVC films increased with the degree of grafting to reach a certain limiting values.

Anionic membranes obtained by radiation grafting of 4-vinylpyridine onto poly(vinyl chloride)

Some properties of the membranes obtained by radiation grafting of 4-vinylpyridine onto poly(vinyl chloride), PVC, have been studied. Quaternization of nitrogen atoms in the grafted films was completely achieved by using Mel and HCL as quaternizing agents. The grafted quaternized pure and plasticized PVC films possess much higher water uptake percent than those grafted unquaternized ones. The quaternized grafted films also show higher electrical conductivity than grafted unquaternized ones. Furthermore, the electrical conductivity of Mel- and HCL-quaternized plasticized PVC films was 100 times that those of quaternized pure, at a given degree of grafting. The tensile strength and elongation percent for the trunk films were measured at various irradiation doses in N 2 atmosphere and in air. The mechanical properties of the wet grafted films were also investigated for films having various degrees of grafting. The good swelling behaviour of the grafted quaternized PVC films and the good mechanical strength of the grafted films may make them acceptable for handling and practical use as anion-exchange membranes.

Fourier‐transform infrared study of conformational changes in plasticized poly(vinyl chloride)

AbstractFourier‐transform infrared spectroscopy has been used for the detection of conformational changes induced by plasticization in atactic poly(vinyl chloride) (PVC). The amount of short trans syndiotactic sequences decrease upon plasticization. This change depends on the amount and kind of plasticizer. Difference spectra emphasize changes in the distribution of gauche defects in the chains as a function of temperature in plasticized PVC films.

Emissivity values for poly(vinyl chloride) with varying plasticizer compositions

The emissivity of plasticized poly(vinly chloride) (PVC) containing varying compositions and amounts of plasticizer was investigated. The four plasticizers examined were dibutyl phthalate (DBP), dioctyl phthalate (DOP), diisodecyl phthalate (DIDP) (Phthalic acid type), and dioctyl adipate (DOA) (adipic acid type). The emmissivity of plasticized PVC film increased almost equally with the difference in the compositions between DOP and DOA. It was also clear that the emissivity of the plasticized PVC film decreased gradually with the molecular sequence length of DBP, DOP, and DIDP.

塩化ビニル樹脂の光分解（気体生成物の分析）

An experimental study was carried out on the photodecomposition of unplasticized and plasticized PVC films. The PVC films were irradiated with a Xenon lamp in the temperature range of 30-50°C. The amount of hydrogen chloride evolved was determined by a chlorine ion-meter. Other gaseous products of the photodecomposition were identified and determined by gas-chromatography. The summary of the results obtained are as follows.(1) Eleven kinds of gaseous products were detected during the photodecomposition of unplasticized PVC film. The main products were hydrogen chloride and carbon dioxide, and their amounts were of the order of 40-60μg/cm2. Hydrogen chloride evolved increased with an increase in temperature, while carbon dioxide decreased.(2) In the case of photodecomposition of PVC film plasticized with Di-2-ethylhexyl phthalate, fifteen kinds of gaseous products were detected. The amount of hydrogen chloride evolved was 1/10-1/7 of that of unplasticized film. Carbon dioxide evolved increased with an increase in temperature. This fact was supposed to be due to the photodecomposition of Di-2-ethylhexyl phthalate. The amounts of olefinic hydrocarbons (ethylene, propylene) were about several tens times that in the case of unplasticized film.

A rapid test for biodegradability of PVC film by pseudomonads.

Summary.Biodegradability of plasticized PVC film by a Pseudomouas fluorescens strain was assessed quickly by determination of ammonia produced during endogenous respiration of the organism. Values for ammonia production from 52 PVC samples after 48 h showed an excellent inverse correlation with weight loss of the film as determined after 14 days, and can form the basis of a rapid method for assessing biodegradability.