Dynamic mechanical spectroscopy applied to study the thermal and photodegradation of poly(2,6-dimethyl-1,4-phenylene oxide)/high impact polystyrene blends

Saron, Clodoaldo; Felisberti, Maria I.

doi:10.1016/j.msea.2003.01.001

Cited by 28 publications

(27 citation statements)

References 20 publications

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“…The major contribution to photodegradation of HIPS is usually attributed to the PB phase, which is constituted of different isomers that present different stabilities to degradation, although the degradation also affects the PS matrix. 6 Exposure to sunlight causes a drastic drop in impact resistance attributed to the photooxidation of the unsaturated rubber phase induced by UV radiation, limiting the lifetime of molded parts in outdoor applications. 4,7 To overcome this problem, it has been suggested that PB be replaced in the polymer composition by a saturated rubber such as poly(ethylene-co-propylene-co-2-ethylidene-5-norbornene), EPDM.…”

Section: Introductionmentioning

confidence: 99%

“…The hydrogen bonded to the same carbon as the phenyl group is labile and its loss occurs by the absorption of energy producing a radical group that undergoes subsequent reactions such as depolymerization and oxidation, resulting in low molar mass compounds. 6,11,12 Differences in sensitivity to individual degradation processes arise from the effects of low amounts of structural polymeric inhomogeneities (e.g., unsatura-tion, oxygenated structures) and nonpolymeric impurities such as metallic contaminants or photoactive pigments. The knowledge of degradation mechanisms of homopolymers and copolymers is helpful only to some extent in elucidation of degradation of polymer blends.…”

Section: Introductionmentioning

confidence: 99%

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Mechanical properties of photoaged in situ polymerized PS/EPDM blends

Lourenço

Felisberti

2007

J of Applied Polymer Sci

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In this study, the mechanical properties of in situ polymerized PS/EPDM blends with different composition were evaluated before and after accelerated photoaging and compared with the properties of commercial HIPS submitted to similar aging conditions (ASTM G53). The mechanical properties of the PS/EPDM blends as well as their photochemical stability are influenced by the polymerization temperature and blend composition. Although the initial mechanical properties of HIPS are superior in comparison with the in situ polymerized PS/EPDM blends, a pronounced drop of them was observed already for short time exposure. For example, after the aging period, all PS/EPDM blends showed higher strain at break than HIPS. Because PS/EPDM blends present higher resistance to photoaging stability than HIPS, the mechanical properties of the HIPS become worse than the other blends as the aging time increases.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Mechanical properties of photoaged in situ polymerized PS/EPDM blends

Lourenço

Felisberti

2007

J of Applied Polymer Sci

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“…This result is in agreement with the shift of the glass transition to higher temperature because trans-1,4 polybutadiene presents a higher T g than the other isomers. 23 The differences between the Raman infrared spectra in the region characteristic of the absorption of the C¼ ¼C bond for HIPS and photoaged HIPS do not justify the intense absorption at 1720 cm À1 observed in the infrared spectrum shown in Figure 7(a), attributed to C¼ ¼O. This fact, associated with the drop of mechanical performance of HIPS, is strong evidence that the degradation of the matrix is also important.…”

Section: Resultsmentioning

confidence: 92%

“…This should also be true for blends with PPO, as previously verified from dynamic mechanical analyses. 23 …”

Section: Resultsmentioning

confidence: 99%

Thermal and photochemical degradation of PPO/HIPS blends

Saron

Sánchez

Felisberti

2007

J of Applied Polymer Sci

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In general, polymer blends show a degradation behavior different from a simple combination of the individual components, making any forecast difficult without experiments. Interactions between polymers can sensibilize or stabilize the blend against degradation. In this work, the thermal and photooxidative degradation of blends of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) and high impact polystyrene (HIPS) have been studied under accelerated conditions. The extent of degradation was accompanied by infrared spectroscopy (FTIR) and Raman spectroscopy (FT-Raman) and impact resistance and strain-stress testing followed its influence on the macroscopic properties of the blends. The results showed that HIPS and the blend containing 60 wt % of PPO are more susceptible to thermal and photochemical degradation, while the blends containing 40 and 50 wt % of PPO are more stable. Infrared and Raman spectroscopic analyses showed that the degradation of HIPS and its blends is caused not only by degradation of the polybutadiene phase. Effects of interactions, such as exchange of energy in excited state between the PPO and PS components of the polymeric matrix may also be responsible for the degradation and loss of mechanical properties of the PPO/HIPS blends. The chemical degradation directly affects the mechanical properties of the samples with photodegradation being more harmful than the thermal degradation at 758C.

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“…Standard deviations around 2% have been obtained for high quality CFRP laminates. Dynamic mechanical analysis (DMA) or dynamic mechanical thermal analysis (DMTA) indicate damage in polymers or PMC (46), and aging effects in polymers by a shift in the transition temperature (47). DMA, DMTA, and additional thermal analysis methods are discussed and compared in an application on PNC in Ref.…”

Section: Mechanical Test Methodsmentioning

confidence: 99%

Nondestructive Testing of Polymers and Polymer–Matrix Composites

Brunner

Hack

Neuenschwander

2015

Encyclopedia of Polymer Science and Technology

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Because of their unique properties, polymers and polymer–matrix composites pose both challenges and opportunities for nondestructive testing. The increasing use of these materials creates a demand for nondestructive verification of various properties or specifications, determination of structural integrity, or prediction of service‐life. On the other hand, development of new nondestructive test methods, improved sensitivity, or faster data acquisition and analysis may allow for nondestructive testing applications that hitherto did not seem feasible or economical. This article provides a brief overview of established methods and emerging applications in nondestructive testing of polymers and polymer–matrix composites.

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Dynamic mechanical spectroscopy applied to study the thermal and photodegradation of poly(2,6-dimethyl-1,4-phenylene oxide)/high impact polystyrene blends

Cited by 28 publications

References 20 publications

Mechanical properties of photoaged in situ polymerized PS/EPDM blends

Mechanical properties of photoaged in situ polymerized PS/EPDM blends

Thermal and photochemical degradation of PPO/HIPS blends

Nondestructive Testing of Polymers and Polymer–Matrix Composites

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