ISSN:1083-5601    

DOI:10.1002/vnl.730010102.n

出版商:Society of Plastics Engineers    

年代:1995

数据来源: WILEY

ISSN:1083-5601    

DOI:10.1002/vnl.730010103.n

出版商:Society of Plastics Engineers    

年代:1995

数据来源: WILEY

摘要:

AbstractRigid PVC profiles for window frames are required to follow quality standards (usage properties and aging resistance). Our concern is to describe the role of additives and mainly thermal stabilizers on the required properties. Until recently, PVC stabilization was based on heavy metal soaps in the European PVC building industry. Though their resulting efficiency was not questioned, problems of toxicity were raised. Regarding the ecological pressure increase, numerous investigations on co‐stabilizers have been carried out in order to improve the performances of mixed Ca/Zn systems. Our results show the properties of rigid profiles stabilized with Ca/Zn systems. First, the extruded profiles properties such as optical (color) and mechanical properties (impact resistance…) are shown. The aging resistance of toxic heavy metal free vinyl formulations is also studied in comparison with typical Pb/Ba/Cd. The performances achieved indicate that an opportunity to move from toxic heavy metallic stabilizers to mixed Ca/Zn systems, resulting, perhaps, in wider development of Ca/Zn stabilizing systems for food packaging and medical plast

ISSN:1083-5601    

DOI:10.1002/vnl.730010104.n

出版商:Society of Plastics Engineers    

年代:1995

数据来源: WILEY

摘要:

AbstractThe behavior of PVC plastisols during gelation and fusion was studied by the ATR‐FTIR technique (Attenuated Total Reflectance‐Fourier Transform Infrared Spectroscopy). DBP, DOP, and DIDP, three common phthalate plasticizers for PVC, were used in plastisols formulations. Three heating rates—5, 10 and 15°C/min—and formulations with different plasticizer concentrations were studied. The IR spectra of a plastisol coincides with the IR spectra of the plasticizer except for the bands at 1435 and 613 cm−1from the PVC (CH2wagging and C—Cl stretching, respectively). When the plastisol is heated, a progressive decrease of the plasticizer bands areas can be observed, while bands from PVC increase their intensity, probably because of the adsorption of the plasticizer by the resin. On cooling, the area of all bands follows the same path as when heating, but the paths separate at a certain temperature, showing the irreversible nature of this process. The analysis of the band at 1280 cm−1(C(O)—O from plasticizer) during heating and cooling, shows that the temperature of separation areas (Ts) takes place at temperatures coherent with plasticizer compatibility. Studies at different heating rates and different plasticizer content are in good agreement with results using other techniques, available i

ISSN:1083-5601    

DOI:10.1002/vnl.730010105.n

出版商:Society of Plastics Engineers    

年代:1995

数据来源: WILEY

摘要:

AbstractThe kinetics involved in the thermal decomposition of PVC plastisols and unmixed PVC‐plasticizer systems were compared using dynamic thermogravimetric (TG) analysis. Three kinetic models were tested. In all cases thermograms obtained at different heating rates were simultaneously correlated with the same constants. Significant differences indicative of PVC‐plasticizer (DOP) interactions were found between the plastisol systems and the unmixed PVC‐plasticizer systems. When the plasticizer is in the paste, its evolution suffers a delay with respect to the case when PVC and plasticizer were separated. The activation energy for DOP evolution takes the value 109.2 in the first case and 81.6 KJ/mol in the second case. PVC decomposition takes place at lower temperatures when it is in the paste, and its activation energy is 177.4 and 206.7 KJ/mol for PVC in plastisol and unmixed PVC, respect

ISSN:1083-5601    

DOI:10.1002/vnl.730010106.n

出版商:Society of Plastics Engineers    

年代:1995

数据来源: WILEY

摘要:

AbstractAccurate molecular weight characterization of PVC is necessary before attempting to modify the properties of the polymer using additives and/or process the compound in some fashion. Commercial PVC resins are characterized by many different dilute solution viscosity methods. Manufacturers characterize their resins using K values, specific viscosity, relative viscosity, viscosity numbers, and inherent viscosity. Each of these methods can vary according to solvent used, testing temperature, and resin concentration. This paper reviews the technical literature and information published by the major PVC resin producers regarding molecular weight characterization. The information in this review should be useful for scientists and engineers in the PVC industry to translate between and among the various test methods for molecular weight characterizations.

ISSN:1083-5601    

DOI:10.1002/vnl.730010107.n

出版商:Society of Plastics Engineers    

年代:1995

数据来源: WILEY

摘要:

AbstractRigid vinyl foam offers fabricators a maintenance‐free alternative to wood. It is suitable for both internal and external uses, and unlike wood, vinyl foam products will not rot, warp, or peel, and will never need painting. In order to thoroughly evaluate potential applications for foam PVC, samples were provided to a commercial cabinet manufacturer to obtain his perspective of pertinent properties and potential applications. Results of this evaluation are presented along with processing and formulation recommendations for making good‐quality PVC f

ISSN:1083-5601    

DOI:10.1002/vnl.730010108.n

出版商:Society of Plastics Engineers    

年代:1995

数据来源: WILEY

摘要:

AbstractPrompted by commercial significance and academic interest, extensive model compound andin‐situstudies of PVC degradation/stabilization appear in the literature. This paper presents the results of somein‐situstudies of the chemical reaction pathways undergone by organotin thioglycollate esters during PVC stabilization. Infrared spectroscopy indicates that in the case of diocyltin bis(isooctylthioglycollate), not only is the mercaptoester/chloride generated, but also the corresponding thioglycollate (Oct2Sn TG). The extent to which this species is observed is dictated by the processing technique. An attempt is made to correlate the chemical reaction pathway of the organotin compounds with the changes (unsaturation) within the polymer. The possible relevance of these observations to the phenomenon of mono/di synergism is also discussed. While these studies extend our knowledge of the organotin stabilization of PVC, they also show that our understanding is far from compl

ISSN:1083-5601    

DOI:10.1002/vnl.730010109.n

出版商:Society of Plastics Engineers    

年代:1995

数据来源: WILEY

摘要:

AbstractThis paper describes Miconite (hydrated potassium, magnesium aluminosilicate) and explains the processability and properties of Miconite‐filled propylene homopolymer. With particles averaging 2.5 and 44 microns, this study found the compound processability, as given by its melt index, unchanged for filler loadings lower than 35%. Tensile strength of the original polymer doubled with the addition of the first 10% of Miconite and stayed constant for all loadings tested up to 60%. Tensile modulus increased linearly with filler loading. Elongation and impact behavior showed negligible decreases for loadings lower than 30%. Deterioration by ultraviolet and/or heat‐aging was negative. Miconite provides matrix materials with fire and smoke retarding qualit

ISSN:1083-5601    

DOI:10.1002/vnl.730010110.n

出版商:Society of Plastics Engineers    

年代:1995

数据来源: WILEY

摘要:

AbstractSome of the additives used in plastics formulations, such as flame retardants, fillers, heat distortion temperature modifiers, and pigments, can have a detrimental effect on the impact resistance of the material. Impact modifiers can sometimes be used to “correct” for the detrimental effects of these additives by boosting the impact performance of the material. The functions of core/shell impact modifiers in improving impact resistance are described. Some general guidelines for selecting impact modifier products are discus

ISSN:1083-5601    

DOI:10.1002/vnl.730010111.n

出版商:Society of Plastics Engineers    

年代:1995

数据来源: WILEY