Photochemical degradation of poly(ethylene terephthalate). III. Determination of decomposition products and reaction mechanism

Day, M.; Wiles, D. M.

doi:10.1002/app.1972.070160118

Cited by 154 publications

(83 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The changes in bonding structure observed in Figure 9 are consistent with the established mechanisms for LDPE [43] and PET [44].…”

Section: Chemical Characterizationsupporting

confidence: 85%

Optical and chemical effects governing femtosecond laser-induced structure formation on polymer surfaces

Assaf¹,

Kietzig²

2018

Materials Today Communications

View full text Add to dashboard Cite

With the emergence of femtosecond technology, laser machining has recently led to the creation of novel porous structures on polymers. However, the mechanism behind their formation is yet to be understood. In this study, the dependence of femtosecond laser-induced surface structure on processing parameters is established at two distinct wavelengths (800 nm and 275 nm) for six different polymer films: LDPE, PC, PET, PLA, PMMA, and PTFE. All of the observed structures are then optically and chemically characterized as a first step towards elucidating their formation mechanism. The threshold fluence at operating conditions was determined to be the main parameter affecting porosity formation during machining. Furthermore, for transparent films, a transition from multiphoton to linear absorption is observed to occur at 800 nm but not at 275 nm. This shift in optical properties was determined to be a major contributor to incubation effects.These observations are also in agreement with UV/VIS analysis as measurements show that polymers with a cut-off wavelength lower than that of the laser beam undergo a shift in absorption behavior. Finally, some polymers experience a continuous darkening of their surface with increasing fluence due to an increasing degree of photo-oxidation.

show abstract

“…The changes in bonding structure observed in Figure 9 are consistent with the established mechanisms for LDPE [43] and PET [44].…”

Section: Chemical Characterizationsupporting

confidence: 85%

Optical and chemical effects governing femtosecond laser-induced structure formation on polymer surfaces

Assaf¹,

Kietzig²

2018

Materials Today Communications

View full text Add to dashboard Cite

show abstract

“…An obvious challenge is that polymeric films degrade when exposed to solar irradiation, oxygen, and moisture, i.e., conditions that are found outdoors where the photocatalytic system are to operate [54][55][56][57][58][59]. Moreover, as the oxidative degradation products include volatiles such as carbon dioxide and carbon monoxide, employing polymeric substrates for photoconversion of CO 2 could seem like Sisyphus' work [60][61][62][63]. In spite of this, polymeric substrates foils remain interesting as carrier foils since it is the total amount of carbon dioxide converted that matter, i.e., the amount of carbon dioxide photocatalytically converted or bound should be larger than the amount of oxidized carbon species released during substrate decomposition.…”

Section: Flexible Substrates As Carrier Foilsmentioning

confidence: 98%

Fixation of Carbon Dioxide Using Molecular Reactions on Flexible Substrates

Jensen

Krebs

2014

Green Chemistry and Sustainable Technology

View full text Add to dashboard Cite

“…Neste esquema, os radicais R podem ser gerados por reações tipo Norrish I [38] ou nesta reação cíclica.…”

Section: Obtenção De Filmesunclassified

Estudo do efeito do envelhecimento sob radiação UV no transporte de água em filmes de PET reciclados de bebidas carbonatadas

Vichessi

Filho

2008

Polímeros

View full text Add to dashboard Cite

Resumo: Este trabalho descreve um estudo sobre o efeito do envelhecimento sob radiação UV no transporte de água em filmes planos de PET reciclados de garrafas de bebidas carbonatadas. A partir do formalismo termodinâmico utilizando a relação de Eyring e os resultados de coeficientes de permeabilidade, foram determinadas a entropia e a entalpia de ativação para o transporte da água. Estas funções representadas num gráfico de efeito de compensação termodinâmica permitiram correlacionar a degradação do material, avaliada via espectroscopia na região do infravermelho com transformada de Fourier, com o transporte de água. Foram analisados os possíveis efeitos da presença de estabilizantes, pigmentos e história de processamento. Palavras-chave: PET, reciclagem, transporte de água, efeito de compensação termodinâmica, degradação, FT-IR. Study of the UV Ageing Effect on Water Transport through PET Films Recycled from Beverage BottlesAbstract: This work describes a study about the UV ageing effect on water transport through PET film sheets recycled from beverage bottles. Using a thermodynamic formalism based on the Eyring relationship and results of water permeability coefficient, it is possible to determine the entropy and enthalpy of activation for the water transport process. These functions were correlated using the compensation thermodynamic plot and correlations were made between the degradation of the PET samples, measured by FTIR, and transport properties. Also, possible effects from the presence of stabilizers, pigments and processing history were analyzed. Keywords: PET, recycling, water transport, thermodynamic compensation effect, degradation, FTIR. IntroduçãoNas últimas décadas, a aplicação de termoplásticos cresceu aceleradamente devido às propriedades que estes materiais apresentam: tais como, boa moldabilidade a quente e resistência mecânica, baixa densidade, transparência, capacidade de coloração e/ou impressão, boa resistência mecânica e principalmente baixo custo [1,2] . O problema do descarte dos resíduos poliméricos, que ocupam grande parte do lixo urbano mundial e são de difícil decomposição, surgiu em conjunto com o consumo acelerado.A reciclagem destes resíduos permitiria em parte, solucionar o problema ambiental bem como possibilitaria o desenvolvimento de novos materiais a partir de blendas e compósitos que agregam maior valor ao material pós-consumo. Devido à baixa reciclabilidade dos polímeros, o custo de recuperação pode ser superior ao da obtenção da matéria-prima, além da qualidade do material reciclado ser inferior à resina virgem [1] . Entretanto, tomando-se como exemplo materiais commodities, os custos de recuperação do poli(tereftalato de etileno)(PET) e polietileno de alta densidade (HDPE) são inferiores ao valor da matéria-prima, com o preço do barril de petróleo a U$ 20,00 e U$ 35,00. Em 2005, o valor do barril de petróleo situou-se na faixa de U$ 50,00, tornando assim a reciclagem destes materiais economicamente viável [3] . Existem três tipos de processos de reciclagem poliméri-ca:...

show abstract

Photochemical degradation of poly(ethylene terephthalate). III. Determination of decomposition products and reaction mechanism

Cited by 154 publications

References 23 publications

Optical and chemical effects governing femtosecond laser-induced structure formation on polymer surfaces

Optical and chemical effects governing femtosecond laser-induced structure formation on polymer surfaces

Fixation of Carbon Dioxide Using Molecular Reactions on Flexible Substrates

Estudo do efeito do envelhecimento sob radiação UV no transporte de água em filmes de PET reciclados de bebidas carbonatadas

Contact Info

Product

Resources

About