Fotodegradação de compósitos de poliestireno/argila montmorilonita: efeito do tipo de argila e presença de sal

Oliveira, Camila F. de P.; Demarquette, Nicole R.; Carastan, Danilo J.; Fechine, Guilhermino J. M.

doi:10.1590/s0104-14282012005000010

Cited by 10 publications

(7 citation statements)

References 17 publications

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“…According to Araujo et al , the coupling agent may act with a pro‐degrading character, directed toward the polymer matrix. From Oliveira et al, , some materials retard the degradation, but in certain circumstances, depending on the materials that are present, the coupling agents can induce the converse effect: instead, they may act as accelerators in the degradation process, as observed in this study.…”

Section: Resultssupporting

confidence: 60%

The photodegradation and biodegradation of rEPS/curaua fiber composites

et al. 2013

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The development of composite materials comprised of postconsumer polymers and natural fibers is important for the possibility to obtain materials that are more compatible with the environment. Depending on the application of these materials and their final disposal, the relevant degradation processes must be considered in the studies of these materials. The aim of this work is to evaluate the effect of the degradation process in simulated soil and in the aging accelerated UV chamber on the properties (tensile strength, chemical, morphology) of the composites developed with recycled expanded polystyrene matrix reinforced by curaua fiber. In the tensile strength tests, it was found that the presence of the curaua fiber and the coupling agent did not have significant effect in the degradation processes of the polymer matrix. However, the use of the coupling agent without the addition of fiber curaua promoted the accelerated degradation of the matrix. The carbonyl index was used as the main assessment parameter of the degradation of the composites, since an increasing in the carbonyl index was observed in the initial periods of degradation decreasing for longer time periods. The presence of cracks in the samples following exposure to UV was observed, but no biofilm formation was identified in the samples exposed to the simulated soil. POLYM. COMPOS., 34:967-977,

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Section: Resultssupporting

confidence: 60%

The photodegradation and biodegradation of rEPS/curaua fiber composites

et al. 2013

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“…After organophilization, these results showed only a slight decrease in the percentage of MgO in the clay, probably, because the Mg 2+ cations participate in the cation exchange process. 25…”

Section: Methodsmentioning

confidence: 99%

The effect of clay organophilization on wood plastic composite (WPC) based on recycled high density polyethylene (HDPE) and coir fiber

Nunes¹,

Farias

Medeiros

et al. 2021

Progress in Rubber, Plastics and Recycling Technology

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One way to optimize composite mechanical properties is through hybridization with small amounts of reinforcing fillers. Thus, this study investigates the effect of incorporation of 3 wt% of clay (BT) and organoclay (OBT) on the properties of a recycled wood plastic composite (WPC) based on HDPE and 20 wt% of coir fiber compounded with 5 wt% of maleic anhydride-grafted polypropylene (PP-g-MA), as coupling agent, and 5 wt% of Struktol TPW 113, as lubricating agent. Raw materials were characterized by X-ray fluorescence (XRF), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). Coir fiber was characterized by optical microscopy and TGA. Wood plastic formulations (with clay and organoclay) were prepared in an internal mixer coupled to a torque rheometer operating at 190°C, 60 rpm for 10 min. Then, the mixtures were compression molded. Formulations were characterized by SEM, TGA, DSC, tensile and water absorption tests. FTIR analysis showed the characteristic bands of organophilic clay. XRD showed an increment in the interplanar distance of the clay, after the incorporation of quaternary ammonium salt (distearyl dimethyl ammonium chloride, Praepagen® WB), confirming the organoclay formation. Organophilization decreases the clay hydrophilic character and reduces the water uptake of WPC-BT. Despite the fact that BT incorporation led to WPC nanocomposite with intercalated structure, this WPC-clay composition did not show a significant increase in tensile strength and elongation at break. The poor interfacial adhesion between the raw materials and the polymer matrix, the low aspect ratio provided by coir fibers and also, the partially intercalated structure of composites have contributed to this behavior.

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“…Os danos causados pela foto-oxidação de materiais poliméricos também são aplicados aos materiais compósitos do tipo polímero/argila, no entanto, apesar de existir vários relatos na literatura a respeito de polímeros/silicatos, pouca atenção tem sido dada ao seu comportamento durante a fotodegradação [7][8][9][10] . Em geral, os estudos de processos foto-oxidativos de materiais compósitos polímero/argila mostram que a presença da argila acelera os processos de degradação dos mesmos quando comparados ao polímero puro [11][12][13] .…”

Section: Introductionunclassified

Influência de estabilizantes na degradação foto-oxidativa de filmes de compósitos de SWy-1/poli(óxido de etileno)

2015

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ResumoCompósitos de poli(óxido de etileno) (PEO) com argila montmorilonita SWy-1 e estabilizantes (2-hidroxibenzofenona e tinuvin 770) foram preparados pelo método de intercalação em solução. Os filmes obtidos foram expostos a irradiação UV, e os produtos da fotodegradação foram monitorados por FTIR (Fourier Transform Infrared Spectroscopy, ou Espectroscopia no infravermelho por transformada de Fourier) e SEC (Size Exclusion Chromatography, ou cromatografia de exclusão por tamanho). O PEO puro apresentou maior coeficiente de degradação, k d, comparado com as demais amostras. O sistema que apresentou o menor valor para o coeficiente de degradação (k d = 1,9×10-6 mol g -1 h -1 ) foi o compósito de PEO/5%SWy-1 com 0,25% de tinuvin 770. Nesse caso, a estabilização da matriz de PEO pode ser atribuída à argila juntamente com o tinuvin 770. A argila dispersa e absorve a irradiação UV, e o tinuvin age como estabilizante do tipo HALS (do inglês hindered amine light stabilizer, ou estabilizantes à luz tipo aminas impedidas). Palavras-chave: poli(óxido de etileno), montmorilonita, fotoestabilizantes, degradação foto-oxidativa. AbstractPoly(ethylene oxide) (PEO) with SWy-1 montmorillonite and stabilizers (2-hydroxybenzophenone and tinuvin 770) composites were prepared by intercalation in solution method. The films of the composites were exposed to UV irradiation. The photodegradation products were monitored by FTIR (Fourier Transform Infrared Spectroscopy) and SEC (Size Exclusion Chromatography) method. The PEO pure showed higher degradation rate coefficients, k d , compared to the others samples. The system that showed the lowest value for the degradation rate coefficients (k d = 1.9×10 -6 mol g -1 h -1 ) was the PEO/SWy-1 5% composite with 0.25% of tinuvin 770. In this case, the stabilization of the PEO matrix can be attributed to clay associated with tinuvin 770. The clay scatters and absorbs UV irradiation and tinuvin acts as a stabilizer of the HALS (hindered amine light stabilizers) kind.

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Fotodegradação de compósitos de poliestireno/argila montmorilonita: efeito do tipo de argila e presença de sal

Cited by 10 publications

References 17 publications

The photodegradation and biodegradation of rEPS/curaua fiber composites

The photodegradation and biodegradation of rEPS/curaua fiber composites

The effect of clay organophilization on wood plastic composite (WPC) based on recycled high density polyethylene (HDPE) and coir fiber

Influência de estabilizantes na degradação foto-oxidativa de filmes de compósitos de SWy-1/poli(óxido de etileno)

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