Kinetics of poly(vinyl chloride) thermal degradation by ionizing radiation

In this study, the relationship between ionizing radiation treatment and thermal degradation kinetics of Poly (vinyl chloride) (PVC) polymer film was investigated. The unirradiated and 25 kGy irradiated samples treated with gamma rays or electron beam radiation were submitted to thermogravimetric analysis (TGA) at different heating rates (10 – 30 K.min-1). The TGA data was used to obtain the apparent activation energy values (Ea) according to Flynn-Wall-Ozawa method. TGA analysis suggested that electron beam radiation promotes a slight increase on maximum temperature for dehydrochlorination reaction on PVC. Gamma-rays irradiation caused a small reduction of maximum temperature of HCl evolution of PVC. Thermal degradation kinetics results showed that 25 kGy irradiated samples presents an apparent activation energy values from 104 - 109 KJ.mol-1. The apparent Ea values suggested that 25 kGy gamma radiation or 25 kGy electron beam radiation convert PVC polymer films more prone to HCl evolution due to radiolysis of polymer. Evaluation of the Ea values by Flynn-Wall-Ozawa method allows a good analytical instrument to comprehend dehydrochlorination reaction on irradiated PVC polymer films.

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Thermal Degradation Kinetics of Plasticized Poly (Vinyl Chloride) with Six Different Plasticizers

Journal of Macromolecular Science Part B ◽

10.1080/00222348.2017.1316659 ◽

2017 ◽

Vol 56 (6) ◽

pp. 420-434 ◽

Cited By ~ 8

Author(s):

Qin Wang ◽

Wei Wu ◽

Yanfang Tang ◽

Jianjian Bian ◽

Songwei Zhu

Keyword(s):

Thermal Degradation ◽

Vinyl Chloride ◽

Degradation Kinetics ◽

Thermal Degradation Kinetics ◽

Poly Vinyl Chloride ◽

Kinetics Of

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Thermal degradation kinetics of poly(vinyl chloride-co-vinyl acetate)

Polymer Degradation and Stability ◽

10.1016/s0141-3910(02)00224-0 ◽

2002 ◽

Vol 78 (3) ◽

pp. 519-524 ◽

Cited By ~ 9

Author(s):

Sujay Chattopadhyay ◽

Giridhar Madras

Keyword(s):

Thermal Degradation ◽

Vinyl Acetate ◽

Vinyl Chloride ◽

Degradation Kinetics ◽

Thermal Degradation Kinetics ◽

Poly Vinyl Chloride ◽

Kinetics Of

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Thermal Degradation Kinetics and Modeling Study of Ultra High Molecular Weight Polyethylene (UHMWP)/Graphene Nanocomposite

Molecules ◽

10.3390/molecules26061597 ◽

2021 ◽

Vol 26 (6) ◽

pp. 1597

Author(s):

Iman Jafari ◽

Mohamadreza Shakiba ◽

Fatemeh Khosravi ◽

Seeram Ramakrishna ◽

Ehsan Abasi ◽

...

Keyword(s):

Thermal Stability ◽

Molecular Weight ◽

Thermal Degradation ◽

High Molecular Weight ◽

Degradation Kinetics ◽

Graphene Nanosheets ◽

Thermal Degradation Kinetics ◽

Graphene Nanocomposites ◽

Kinetics Of ◽

Ultra High Molecular Weight

The incorporation of nanofillers such as graphene into polymers has shown significant improvements in mechanical characteristics, thermal stability, and conductivity of resulting polymeric nanocomposites. To this aim, the influence of incorporation of graphene nanosheets into ultra-high molecular weight polyethylene (UHMWPE) on the thermal behavior and degradation kinetics of UHMWPE/graphene nanocomposites was investigated. Scanning electron microscopy (SEM) analysis revealed that graphene nanosheets were uniformly spread throughout the UHMWPE’s molecular chains. X-Ray Diffraction (XRD) data posited that the morphology of dispersed graphene sheets in UHMWPE was exfoliated. Non-isothermal differential scanning calorimetry (DSC) studies identified a more pronounced increase in melting temperatures and latent heat of fusions in nanocomposites compared to UHMWPE at lower concentrations of graphene. Thermogravimetric analysis (TGA) and derivative thermogravimetric (DTG) revealed that UHMWPE’s thermal stability has been improved via incorporating graphene nanosheets. Further, degradation kinetics of neat polymer and nanocomposites have been modeled using equations such as Friedman, Ozawa–Flynn–Wall (OFW), Kissinger, and Augis and Bennett’s. The "Model-Fitting Method” showed that the auto-catalytic nth-order mechanism provided a highly consistent and appropriate fit to describe the degradation mechanism of UHMWPE and its graphene nanocomposites. In addition, the calculated activation energy (Ea) of thermal degradation was enhanced by an increase in graphene concentration up to 2.1 wt.%, followed by a decrease in higher graphene content.

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