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PVC Films

Poly(vinyl chloride). To be converted into film, poly(viayl chloride) [9002-86-22] (PVC) must be modified with heat stabilizers and plasticizers, which increase costs. Plasticized PVC film is highly transparent and soft, with a very high gas-permeation rate. Water-vapor transmission rate is relatively low. At present, PVC film is produced by blown-film extmsion, although casting and calendering are employed for heavier gauges (see Vinyl POLYAffiRS). [Pg.452]

The principal packagiag use of PVC film is as a gas-permeable but water-vapor impermeable wrap for red meat, poultry, and produce. Sparkle and transparency, combined with the abiHty to transmit oxygen to maintain red-meat color, offer advantages in these appHcations. [Pg.452]

Water-borne adhesives are preferred because of restrictions on the use of solvents. Low viscosity prepolymers are emulsified in water, followed by chain extension with water-soluble glycols or diamines. As cross-linker PMDI can be used, which has a shelf life of 5 to 6 h in water. Water-borne polyurethane coatings are used for vacuum forming of PVC sheeting to ABS shells in automotive interior door panels, for the lamination of ABS/PVC film to treated polypropylene foam for use in automotive instmment panels, as metal primers for steering wheels, in flexible packaging lamination, as shoe sole adhesive, and as tie coats for polyurethane-coated fabrics. PMDI is also used as a binder for reconstituted wood products and as a foundry core binder. [Pg.350]

Waterproof. Waterproofing barrier systems may be either hot- or cold-appHed. The hot-appHed generaUy involve a bituminous material such as asphalt used in conjunction with a reinforcing fabric such as roofing felt, cotton, or glass cloth. Cold-appHed can be bituminous or elastomeric materials either in Hquid or sheet form, with or without fabric reinforcement. Liquid elastomeric treatments include neoprene, polyurethanes, and blends of these or epoxies with bituminous materials. Among the commonly used precured elastomeric sheet materials are neoprene, polyisobutylene, EPDM mbber, and plasticized PVC. Polyethylene and PVC films and nonwoven plastic or glass fabric coated with bituminous materials also find use (78). Because these... [Pg.310]

Citric acid is used as a chelating agent in catalyst systems for making resins, and citrate esters are used as plasticizers (qv) in PVC film, especially in food packaging (207). [Pg.186]

PDMS macromonomer was used as a component of block segment to obtain a graft block copolymer with PMMA (Scheme 1) [51-53]. This graft block copolymer is characteristic of surface water repellence, easy peeling, and weatherability superior to simple graft copolymers of the same members. PDMS-b-PVC film also shows long life surface water repellency with weatherability and very low coefficiency of abrasion [18,54]. [Pg.762]

PVC film Di-(2-ethylhexyl) adipate Polyesters of dicarboxyhc acids and diols, average molar mass 2000... [Pg.159]

EB radiation-cured PVC film surface induces a big improvement in tensile strength and excellent printing ink adhesion and adhesive receptance [302]. PVC foams containing plasticizers, thermally activated blowing agents, cross-linkers, and heat stabilizers have been manufactured by EB radiation technology [303]. [Pg.877]

Figure 1.8. Absorption spectra of (a) the colorless form and (b) the colored form of l-butyl-3,3-dimethyl-spiroindolinonaphthooxazine produced by irradiation with UV light in PVC film (1.0 wt%) at 23°C. Figure 1.8. Absorption spectra of (a) the colorless form and (b) the colored form of l-butyl-3,3-dimethyl-spiroindolinonaphthooxazine produced by irradiation with UV light in PVC film (1.0 wt%) at 23°C.
On-line SFE-pSFC-FTD, using formic or acetic acid modified CO2 as an extraction solvent, was used to analyse a dialkyltin mercaptide stabiliser in rigid PVC (Geon 87444) [114]. Hunt et al. [115] reported off-line SFE-pSFC-UV analysis of PVC/(DIOP, chlorinated PE wax, Topanol CA), using methanol as a modifier. Individual additives are unevenly extracted at lower pressures and temperatures, where extraction is incomplete. Topanol CA, the most polar of the three PVC additives studied, could not be fully extracted in the time-scale required (15-20min), even at the highest CO2 temperature and pressure obtainable. However, methanol-modified CO2 enhances extraction of Topanol CA. PVC film additives (DEHP, fatty acids, saturated and aromatic hydrocarbons) were also separated by off-line SFE-preparative SFC, and analysed by PDA and IR [116]. [Pg.443]

When a PVC film is exposed to the UV-visible radiation of an incandescent lamp in the presence of pure chlorine, at room temperature, the chlorine content of the polymer increases from 56.8 % initially to over 70 I after a few hours of irradiation (8). As the reaction proceeds, the rate of chlorination decreases steadily as shown by the kinetic curves of figure 2, most probably because of the decreasing number of reactive sites on the polymer chain that remain available for the attack by chlorine radicals. [Pg.203]

Since chlorinated PVC is totally transparent in the near-UV and visible range, it will not absorb at 488 nm, the emission line of the argon ion laser that we intended to use to perform the carbonization. Therefore C-PVC films were first exposed to the UV radiation of a medium pressure mercury lamp in order to produce the strongly absorbing polyenes. This irradiation was carried out at room temperature in the absence of oxygen, thus preventing the formation of undesirable oxidation products. [Pg.203]

Figure 2. Kinetics of the photochlorination of a PVC film (thickness = 50 ym light intensity = 5.10-9 E s 1 cnf )... Figure 2. Kinetics of the photochlorination of a PVC film (thickness = 50 ym light intensity = 5.10-9 E s 1 cnf )...
Since our main objective was to remove all the chlorine and hydrogen atoms from the polymer chain, C-PVC films were further exposed to the UV radiation of the medium pressure mercury-lamp. This led to a dark brown material w.hich was found to be unable to carry an electrical current, even after extended irradiation time. Therefore we turned to a powerful laser source, a 15 W argon ion laser tuned to its continuous emission at 488.1 nm. At that wavelength, the degraded polymer film absorbs about 30 % of the incident laser photons. The sample was placed on a X-Y stage and exposed to the laser beam at scanning rates in the range of 1 to 50 cm s, in the presence of air. [Pg.207]

Figure 5. UV-visible absorption spectra of PVC and C-PVC films before and after 15 min of UV irradiation in a N2 atmosphere... Figure 5. UV-visible absorption spectra of PVC and C-PVC films before and after 15 min of UV irradiation in a N2 atmosphere...
J cm-2 x 0.3 = 1.5 J cm-2 or 6 x 10-6 einstein cm 2 (1 einstein associated with the 488 nm emission has an energy of 2.45 x10 Joule mole- ). On the other hand, about 7 x 10 mole of HC1 are evolved by each square centimeter of a 20 ym C-PVC film transformed into carbon. The quantum yield of HC1 evolved can then be calculated from the following ratio ... [Pg.209]

Tetrahydrofuran has been reported to exhibit an absorption maximum at 280 nm (52,56), but several workers have shown that this band is not produced by the purified solvent (30,41,57). Oxidation products from THF have been invoked in order to account for the appearance of the 280-nm band in PVC films that are solvent-cast from THF in air (57. 581. However, in some reported cases (56,59), this band was undoubtedly produced, at least in part, by a phenolic antioxidant (2.6-di-tert-butyl-p-cresol)(59) in the solvent. Since certain -alkylphenols have now been shown to be powerful photosensitizers for the dehydrochlorination of PVC (60), it is clear that antioxidant photosensitization might well have been responsible for some of the effects attributed previously (56) to THF alone. On the other hand, enhanced rates of photodegradation under air have also been observed for PVC films cast from purified THF (57), a result which has been ascribed to radical formation during the photooxidation of residual solvent (57,61). Rabek et al. (61) have shown that this photooxidation produces a-HOO-THF, a-HO-THF, and y-butyro-lactone, and they have found that the hydroperoxide product is an effective sensitizer for the photodehydrochlorination of PVC at X = 254 nm (61). [Pg.205]

The effect of HC1 on the photolysis of PVC films has been shown (30) to be complicated by the formation of a thin surface layer oY highly absorbing polyenes. Such a layer may act as an effective filter and reduce dramatically the amount of light which can penetrate to the interior of the film and hence protect the bulk from further degradation. On the other hand Decker has shown (48) that when PVC films were irradiated,... [Pg.222]

Figure 1. Absorption spectra of thermally degraded PVC film irradiated ( > 300... Figure 1. Absorption spectra of thermally degraded PVC film irradiated ( > 300...
Figure 2. Absorbance at 300 nm of thermally degraded PVC films on irradiation (A. > 300 nm) in the presence of various pressures of HCl (O) 0 (X) 50 torr (A) 150 torr ( Z ) 300 torr ( ) 760 torr (27)... Figure 2. Absorbance at 300 nm of thermally degraded PVC films on irradiation (A. > 300 nm) in the presence of various pressures of HCl (O) 0 (X) 50 torr (A) 150 torr ( Z ) 300 torr ( ) 760 torr (27)...
Figure 3. Dependence on the HCl pressure of the extent of the photobleaching of thermally degraded PVC films, measured at 300 nm (21)... Figure 3. Dependence on the HCl pressure of the extent of the photobleaching of thermally degraded PVC films, measured at 300 nm (21)...
Using l,8-diphenyloctatetra-l,3,5,7-ene, (DOT), as a model compound either in dilute, ( 10-5m), hexane or ethanol solutions or incorporated into a film of undegraded PVC confirmed that in the presence of HC1 it underwent a photochemical reaction which resembled that of the polyenes in thermally degraded PVC. The results indicated that the initial rates of reactions proceeding in either solvent showed a second order dependence on HC1 pressure and that the reaction was considerably slower in ethanol than in hexane. Further, when cast in PVC films, the characteristic absorption maxima of DOT were shifted about 16nm to longer wavelengths compared with their absorption in hexane and there... [Pg.226]

By immobilizing Mn(III)-tetrakis(4-sulfonatophenyl)-porphyrin on dioctadecyl-dimethyl ammonium chloride bilayer membranes incorporated into a PVC film, Kuniyoshi et al. [65] developed an epinephrine CL sensor, which allowed determination of epinephrine down to 3 pM with an RSD of 1.0% for 50 pM of this biological compound. Compared with the previously reported epinephrine CL sensor [66], the present authors noted that the alkaline carrier solution, at high concentration levels, caused gradual deterioration of the immobilized catalyst, and this problem could be solved by the use of immobilization techniques other than ion exchange, e.g., solubilization of the catalyst that has octadecyl groups in the bilayer molecules. [Pg.582]

The enforcement in Denmark of EU Directives on food packaging materials is discussed. Enforcement activities considered include studies of total migration from food contact materials, migration from kitchen-and tableware made of melamine plastics and migration of di(2-ethylhexyl)adipate from plasticised PVC films. Activities which need to be undertaken to increase the effectiveness of enforcement activities in the field of migration are described, including development of selfinspection programmes in industry, European network of enforcement, more rapid analysis and provision of information to the consumer. 2 refs. [Pg.45]

With the exception of ethylene vinyl acetate added in the 1980 s, the list of materials and polymers approved as packaging for food irradiated products has remained static for decades. This article supplies details of the approved list, which includes such polymers as polyethylene terephthalate and polyvinyl chloride. The article provides an update on the latest proactive move to expand the list of packaging materials and polymers approved for the irradiation of foods. The expanded list would include ethylene vinyl alcohol, PVC film, ionomers, nylon 66, 6/12 and copolyesters among others. [Pg.90]

Plasticized PVC is tested by covering both sides of the pigmented test sheet with white plasticized PVC films, which are placed between glass or aluminum plates. With a certain weight on it, this sandwich is exposed for 24 hours at a temperature of 80°C (or for 15 hours at 100°C) [41], The thickness of the test sample does not affect the test results. [Pg.66]

P.Y.17 may be used for mass coloration and also to print PVC film. For these purposes, P.Y.17 is frequently prepared on a VC/VAc (vinyl chloride/vinyl acetate) mixed polymer basis. Good dispersibility in plastics makes these preparations suitable even for thin films. The dielectrical properties of P.Y.17 allow its application in PVC cable insulations. [Pg.250]


See other pages where PVC Films is mentioned: [Pg.448]    [Pg.505]    [Pg.527]    [Pg.156]    [Pg.119]    [Pg.870]    [Pg.105]    [Pg.104]    [Pg.203]    [Pg.203]    [Pg.206]    [Pg.207]    [Pg.212]    [Pg.202]    [Pg.210]    [Pg.227]    [Pg.633]    [Pg.30]    [Pg.227]    [Pg.229]   
See also in sourсe #XX -- [ Pg.95 ]




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Plasticised PVC films

The stretching of rigid PVC films

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