Photodegradation mechanisms in poly(2,6-butylenenaphthalate-co-tetramethyleneglycol) (PBN–PTMG). I: influence of the PTMG content

Nagai, Yasutaka; Nakamura, Daisuke; Miyake, Tomoyuki; Ueno, Hitoshi; Matsumoto, Naomi; Kaji, Atsushi; Ohishi, Fujio

doi:10.1016/j.polymdegradstab.2004.10.016

Cited by 23 publications

(5 citation statements)

References 9 publications

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“…In order to obtain a new type of TPEE, the rigid segments other than PBT have been changed and applied in the synthesis of new TPEE. In addition to PBT, poly(ethylene terephthalate) (PET) [1,4], poly(butylene 2,6naphthalene dicarboxylate) [5,6], poly(butylene-co-isophthalate) [7], and aromatic polycarbonate [8] were used as rigid segments.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Characterizations of Poly(trimethylene terephthalate)-b-poly(tetramethylene glycol) Copolymers

Liu

Yao

Run

2013

International Journal of Polymer Science

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A series of poly(trimethylene terephthalate)-b-poly(tetramethylene glycol) (PTT-PTMEG) copolymers were synthesized by two-step melt-polycondensation. The copolymers were characterized by using Fourier transform infrared spectroscopy (FTIR),1H NMR spectroscopy, rheometer, differential scanning calorimetry (DSC), polarized optical microscopy (POM), thermal gravimetric analysis (TGA), and mechanical properties. The results suggest that by increasing the flexible PTMEG contents from 0% to 60 wt%, the copolymers show decreased glass transition temperatures, melting points, melt-crystallization temperatures, hardness, tensile strength, thermostability, and smaller spherulites dimensions; however it has much increased impact strength and elongation at breaking point. Compared with commercial poly(butylene terephthalate) (PBT)-type TPEE with 25 mol% flexible segments, PTT-type TPEE having 25 mol% flexible segments has a lower glass transition temperature, melting point, crystallization temperature, and much lower tensile strength although it has a much higher impact strength than that of PBT-type TPEE, and it is not suitably used as a commercial TPEE.

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Section: Introductionmentioning

confidence: 99%

Synthesis and Characterizations of Poly(trimethylene terephthalate)-b-poly(tetramethylene glycol) Copolymers

Liu

Yao

Run

2013

International Journal of Polymer Science

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“…UV absorption in PS has been found to occur at the benzene ring, causing loss of mechanical properties, chain scission, cross-linking reactions and is a precursor to oxidative degradation (Nagai et al 1999). Nagai et al (2005b) analyzed the photo-degradation of a polyether-polyester elastomer under laboratory conditions and found the degradation mechanism upon UV exposure was a selective degradation of the ether parts of soft segments in the polymer matrix, and resulted in the formation of ester, aldehyde, formate, and propyl end groups.…”

Section: Photo-degradationmentioning

confidence: 99%

Occurrence, Degradation, and Effect of Polymer-Based Materials in the Environment

Lambert

Sinclair

Boxall

2013

Reviews of Environmental Contamination and Toxicology

157

151

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There is now a plethora of polymer-based materials (PBMs) on the market, because of the increasing demand for cheaper consumable goods, and light-weight industrial materials. Each PBM constitutes a mixture of their representative polymer/sand their various chemical additives. The major polymer types are polyethylene, polypropylene,and polyvinyl chloride, with natural rubber and biodegradable polymers becoming increasingly more important. The most important additives are those that are biologically active, because to be effective such chemicals often have properties that make them resistant to photo-degradation and biodegradation. During their lifecycle,PBMs can be released into the environment form a variety of sources. The principal introduction routes being general littering, dumping of unwanted waste materials,migration from landfills and emission during refuse collection. Once in the environment,PBMs are primarily broken down by photo-degradation processes, but due to the complex chemical makeup of PBMs, receiving environments are potentially exposed to a mixture of macro-, meso-, and micro-size polymer fragments, leached additives, and subsequent degradation products. In environments where sunlight is absent (i.e., soils and the deep sea) degradation for most PBMs is minimal .The majority of literature to date that has addressed the environmental contamination or disposition of PBMs has focused on the marine environment. This is because the oceans are identified as the major sink for macro PBMs, where they are known to present a hazard to wildlife via entanglement and ingestion. The published literature has established the occurrence of microplastics in marine environment and beach sediments, but is inadequate as regards contamination of soils and freshwater sediments. The uptake of microplastics for a limited range of aquatic organisms has also been established, but there is a lack of information regarding soil organisms, and the long-term effects of microplastic uptake are also less well understood.There is currently a need to establish appropriate degradation test strategies consistent with realistic environmental conditions, because the complexity of environmental systems is lost when only one process (e.g., hydrolysis) is assessed in isolation. Enhanced methodologies are also needed to evaluate the impact of PBMs to soil and freshwater environments.

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“…It is worth mentioning that the half-lives of various plastics in the ocean are 38 years for PE, 16 years for PP, 35 years for PS, and 44 years for PET, respectively [ 86 ]. In specific situations, the molecular chains of plastic can experience photooxidation (photolysis) due to factors such as temperature, humidity, oxygen, and light [ 61 , 85 , 87 , 88 , 89 , 90 ]. Specifically, this effect utilizes the free radicals generated in the initiation period after linkage breakage to induce autoxidation, ultimately breaking the plastic particles’ linkages and transforming them into small soluble molecules, which completes the degradation [ 85 , 91 ].…”

Section: Introductionmentioning

confidence: 99%

Sources, Degradation, Ingestion and Effects of Microplastics on Humans: A Review

Lin,

Huang,

Chen

et al. 2023

Toxics

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Celluloid, the predecessor to plastic, was synthesized in 1869, and due to technological advancements, plastic products appear to be ubiquitous in daily life. The massive production, rampant usage, and inadequate disposal of plastic products have led to severe environmental pollution. Consequently, reducing the employment of plastic has emerged as a pressing concern for governments globally. This review explores microplastics, including their origins, absorption, and harmful effects on the environment and humans. Several methods exist for breaking down plastics, including thermal, mechanical, light, catalytic, and biological processes. Despite these methods, microplastics (MPs, between 1 and 5 mm in size) continue to be produced during degradation. Acknowledging the significant threat that MPs pose to the environment and human health is imperative. This form of pollution is pervasive in the air and food and infiltrates our bodies through ingestion, inhalation, or skin contact. It is essential to assess the potential hazards that MPs can introduce. There is evidence suggesting that MPs may have negative impacts on different areas of human health. These include the respiratory, gastrointestinal, immune, nervous, and reproductive systems, the liver and organs, the skin, and even the placenta and placental barrier. It is encouraging to see that most of the countries have taken steps to regulate plastic particles. These measures aim to reduce plastic usage, which is essential today. At the same time, this review summarizes the degradation mechanism of plastics, their impact on human health, and plastic reduction policies worldwide. It provides valuable information for future research on MPs and regulatory development.

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Photodegradation mechanisms in poly(2,6-butylenenaphthalate-co-tetramethyleneglycol) (PBN–PTMG). I: influence of the PTMG content

Cited by 23 publications

References 9 publications

Synthesis and Characterizations of Poly(trimethylene terephthalate)-b-poly(tetramethylene glycol) Copolymers

Synthesis and Characterizations of Poly(trimethylene terephthalate)-b-poly(tetramethylene glycol) Copolymers

Occurrence, Degradation, and Effect of Polymer-Based Materials in the Environment

Sources, Degradation, Ingestion and Effects of Microplastics on Humans: A Review

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