Degradation studies on plasticized PVC films submited to gamma radiation

Vinhas, Glória Maria; Souto-Maior, Rosa Maria; Lapa, Camila M.; Almeida, Yêda Medeiros Bastos de

doi:10.1590/s1516-14392003000400012

Cited by 26 publications

(11 citation statements)

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“…gamma radiation) changes are observed on their molecular structure, mainly chain scission, which leads to reduction in molar mass Vinhas et al (2003). …”

Section: Introductionmentioning

confidence: 99%

Photodegradation and photostabilization of polymers, especially polystyrene: review

2013

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Exposure to ultraviolet (UV) radiation may cause the significant degradation of many materials. UV radiation causes photooxidative degradation which results in breaking of the polymer chains, produces free radical and reduces the molecular weight, causing deterioration of mechanical properties and leading to useless materials, after an unpredictable time. Polystyrene (PS), one of the most important material in the modern plastic industry, has been used all over the world, due to its excellent physical properties and low-cost. When polystyrene is subjected to UV irradiation in the presence of air, it undergoes a rapid yellowing and a gradual embrittlement. The mechanism of PS photolysis in the solid state (film) depends on the mobility of free radicals in the polymer matrix and their bimolecular recombination. Free hydrogen radicals diffuse very easily through the polymer matrix and combine in pairs or abstract hydrogen atoms from polymer molecule. Phenyl radical has limited mobility. They may abstract hydrogen from the near surrounding or combine with a polymer radical or with hydrogen radicals. Almost all synthetic polymers require stabilization against adverse environmental effects. It is necessary to find a means to reduce or prevent damage induced by environmental components such as heat, light or oxygen. The photostabilization of polymers may be achieved in many ways. The following stabilizing systems have been developed, which depend on the action of stabilizer: (1) light screeners, (2) UV absorbers, (3) excited-state quenchers, (4) peroxide decomposers, and (5) free radical scavengers; of these, it is generally believed that excited-state quenchers, peroxide decomposers, and free radical scavengers are the most effective. Research into degradation and ageing of polymers is extremely intensive and new materials are being synthesized with a pre-programmed lifetime. New stabilizers are becoming commercially available although their modes of action are sometimes not thoroughly elucidated. They target the many possible ways of polymer degradation: thermolysis, thermooxidation, photolysis, photooxidation, radiolysis etc. With the goal to increase lifetime of a particular polymeric material, two aspects of degradation are of particular importance: Storage conditions, and Addition of appropriate stabilizers. A profound knowledge of degradation mechanisms is needed to achieve the goal.Electronic supplementary materialThe online version of this article (doi:10.1186/2193-1801-2-398) contains supplementary material, which is available to authorized users.

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“…gamma radiation) changes are observed on their molecular structure, mainly chain scission, which leads to reduction in molar mass Vinhas et al (2003). …”

Section: Introductionmentioning

confidence: 99%

Photodegradation and photostabilization of polymers, especially polystyrene: review

2013

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“…A rigid PVC film is rendered flexible by incorporation of liquid plasticizers (DOP) into base resin. The plasticizers minimize the dipolar interactions between polymer's chains and promote their mobility . Thus, the lower values of Ts and Ym were obtained for PVC test specimens.…”

Section: Resultsmentioning

confidence: 99%

Analysis of PVC Produced With An Environmentally Friendly Additive Exposed to Gamma Radiation

Silva

Araújo

Madaleno

et al. 2019

Macromolecular Symposia

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Commercial Poly(vinyl chloride) (PVC) compounds are based on the combination of the polymer and additives that gives the formulation necessary for the end‐use. In medical‐device applications, PVC may be treated by gamma irradiation in sterilization process. As a consequence of ionization during irradiation, PVC chains undergo simultaneously crosslinking and scission effects. Therefore, it is necessary the study of new additives with radiolytic stabilization characteristics. In this study, the vegetable oil extracted from coffee grounds (OCG) was incorporated in PVC resin as an additive to produce PVC films and PVC test specimens. The viscosity measurements showed that OCG is a promising radioprotection at 0.5 wt% concentration. The results of mechanical and thermal properties are also discussed. The aim of this study is to show that it is possible to develop a formulation for processing PVC with radiation resistance and, at the same time, friendly to the environment due to recycle the wastes from coffee industry.

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“…A transfer of charge should be taking place in a similar way among the adjacent chains of A0. A weak dipole interaction is reported [20] to exist between H þ and Cl À of adjacent chains in PVC. This interaction must be providing a path for the flow of charge under the influence of electric field.…”

Section: Discussionmentioning

confidence: 97%

DC Electrical Study of Modified PMMA, PVC and their Blend

Soman

Kelkar

2010

Macromolecular Symposia

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Summary: Thin films of high molecular weight PMMA, PVC and their blend were prepared with solution cast method. Further they were modified by adding Camphor Sulphonic Acid (CSA) to them. DSC studies indicate single glass transition temperature (Tg) for unmodified as well as modified blends indicating the miscibility of polymers. FTIR studies show the interaction between CSA-PVC, CSA-PMMA, CSA-(PVCþPMMA) blend. The D.C. electrical study was carried out at various temperatures from room temperature (307 K) to 373 K. After modification the variation of DC conductivity (s) is found to decrease in PVC and the PVC-PMMA blend whereas it is found to increase in PMMA with rise in temperature.

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Degradation studies on plasticized PVC films submited to gamma radiation

Cited by 26 publications

References 1 publication

Photodegradation and photostabilization of polymers, especially polystyrene: review

Photodegradation and photostabilization of polymers, especially polystyrene: review

Analysis of PVC Produced With An Environmentally Friendly Additive Exposed to Gamma Radiation

DC Electrical Study of Modified PMMA, PVC and their Blend

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