Characterization of the influence of specimen thickness on the aging behavior of a polypropylene based model compound

Grabmayer, Klemens; Beißmann, Susanne; Wallner, Gernot M.; Nitsche, David; Schnetzinger, Karl; Buchberger, Wolfgang; Schobermayr, Harald; Lang, Reinhold W.

doi:10.1016/j.polymdegradstab.2014.11.004

Cited by 25 publications

(27 citation statements)

References 38 publications

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“…Hence, the oxidation temperature does not unambiguously reflect the end of the induction time for investigated grades and temperatures. As shown by Grabmayer et al ., the critical oxidation temperature is also dependent on the stabilizer system but almost independent on the specimen thickness. Presumably, the lower critical oxidation temperature values of the PP‐REβ grade are related to additional stabilizers such as small amounts of thiosynergist s (e.g., Irganox PS‐800 or 802 by BASF (Ludwigshafen am Rhein, Germany)).…”

Section: Resultsmentioning

confidence: 70%

“…Within the first aging intervals, an initial drop up to 15 °C of the oxidation temperature was observed for all exposure temperatures. This drop is related primarily to physical loss like evaporation of the antioxidants and was more pronounced for the α‐crystalline PP‐R grades . A steady decrease in oxidation temperature was monitored for all PP‐R grades with faster decline at higher exposure temperatures.…”

Section: Resultsmentioning

confidence: 94%

“…A further physical effect is the diffusion and evaporation of the antioxidants . The solubility and rate of evaporation in hot air are dependent on the specific formulation of polymeric materials . Although, PP‐RBα and PP‐REβ exhibited the same initial antioxidant concentrations, a more pronounced drop of antioxidant content was obtained within the first aging period.…”

Section: Resultsmentioning

confidence: 99%

“…AGRU Kunststofftechnik GmbH extruded 2 mm thick sheets on an Extrudex EN45‐25D extruder. For aging experiments 100 μm thick micro‐sized specimens were prepared by automated, computerized‐numerical‐control‐aided edgewise planning . Hot air exposure was performed at 95, 105, 115, 125, and 135 °C in Binder FED 53 (Tuttlingen, Germany) heating chambers with forced circulation.…”

Section: Methodological Approachmentioning

confidence: 99%

“…Preliminary investigations on the hot air aging behavior of PP block and random copolymers have been carried out by Povacz et al . or Grabmayer et al . At an exposure temperature of 135 °C, a significant effect of the pigment type (carbon black vs. carbon nanotube), the stabilizer system, and also the specimen thickness has been reported in the previous work .…”

Section: Introductionmentioning

confidence: 93%

See 4 more Smart Citations

Hot air aging behavior of polypropylene random copolymers

Grabmann

Wallner

Maringer

et al. 2018

J of Applied Polymer Sci

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This article deals with the global aging behavior of three polypropylene random copolymer (PP-R) materials with varying primary structure and morphology. Hot air aging experiments at elevated temperatures from 95 to 135 C were carried out using micro-sized specimens with a thickness of 100 μm. Technological and analytical aging indicators were monitored for an exposure time of up to 750 days. Independent of comonomer type (ethylene vs. butylene) and morphology (α vs. β crystal form) a critical molar mass of 300 kg mol −1 was obtained. The consumption of antioxidants was slower for the β-nucleated PP-R grade with finer spherulitic structure. The β-grade outperformed the α-crystal PP-R grades resulting in about 20% higher time-to-embrittlement values.

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Section: Resultsmentioning

confidence: 70%

Section: Resultsmentioning

confidence: 94%

Section: Resultsmentioning

confidence: 99%

Section: Methodological Approachmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 93%

See 3 more Smart Citations

Hot air aging behavior of polypropylene random copolymers

Grabmann

Wallner

Maringer

et al. 2018

J of Applied Polymer Sci

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Synergistic Effects of Amine‐Containing Antioxidants on the Aging Performances of Ethylene Propylene Diene Rubber

Li¹,

Zhou²,

Cao³

et al. 2020

ChemistrySelect

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In this study, two types of amine-containing antioxidants composed of 2-mercaptobenzimidazole zinc (MBZ) and 4,4'-bis (α, α-dimethylbenzyl) diphenylamine (445) were used to improve the thermo-oxidative aging resistance of ethylene propylene diene rubber (EPDM). The synergistic effects on the performances of EPDM and the corresponding aging mechanism were investigated by FTIR, tensile test, differential scanning calorimetry (DSC), rotary rheometer and other equipment. The results showed that the hardness increased gradually with the increasing aging time regardless of the type of antioxidants. Compared with the EPDM without antioxidants, the elongation retention of those samples with MBZ or 445 improved obviously. Additionally, the sample with the MBZ/445 complex showed the highest retention values at the same aging time. The antioxidative mechanisms were further analyzed by carbonyl index, activation energy and oxidation induction time, respectively. Results indicated that the degree of oxidation of EPDM using the MBZ/445 complex was much lower than other control systems during the aging process. As a result, the MBZ/445 complex was a favorable antioxidative additive for EPDM.[a] Dr.

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High‐temperature stabilization of polypropylene using hindered phenol–thioester stabilizer combinations, Part 1: Optimization and efficacy via nondust blends

Allen

Jones

Liauw

et al. 2021

Vinyl Additive Technology

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The thermal degradation of unstabilized polypropylene has been investigated under long‐term processing (twin extruder) and thermal aging at 150°C, with additive concentration studies on combinations of an established hindered phenolic antioxidant (pentaerythritol tetrakis (3‐(3,5‐di‐tert‐butyl‐4‐hydroxyphenyl) propionate) [S1010] and two popular thioesters (distearyl‐3,3′‐thiodipropionate [DSTDP] and didodecyl‐3,3′‐thiodipropionate [DLTDP]) using melt flow rate, carbonyl index and powder diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) (FTIR), and differential scanning calorimetry (DSC) (oxidation induction time [OIT]) and ultimate embrittlement time (Fracture) on injection‐molded test pieces. It was found that 20:80 phenol:thioester ratios provided the best long‐term thermal stability (LTTS); however, this was the reverse for processing stabilization (80:20), underlining the antioxidant nature of the two stabilizers (long term vs. melt). Melt preblending of the stabilizers (to form a no‐dust blend) gave rise to improved LTTS. DRIFTS FTIR indicated that there was an improvement in preblending the additives, which removed any volatile impurities. Increased additive dispersion and localized potential efficacy in the stabilization cycle is important, as well as possible improved addition of the additives to the extruder rather than fine powder. The data are discussed in relation to the long‐term stabilization of polypropylene in high‐temperature applications such as under the bonnet of automobiles where minimizing stabilizer losses and maximizing synergy are important.

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Characterization of the influence of specimen thickness on the aging behavior of a polypropylene based model compound

Cited by 25 publications

References 38 publications

Hot air aging behavior of polypropylene random copolymers

Hot air aging behavior of polypropylene random copolymers

Synergistic Effects of Amine‐Containing Antioxidants on the Aging Performances of Ethylene Propylene Diene Rubber

High‐temperature stabilization of polypropylene using hindered phenol–thioester stabilizer combinations, Part 1: Optimization and efficacy via nondust blends

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