2 edition of Radiation effects in the polycarbonate of bisphenol-A found in the catalog.
Radiation effects in the polycarbonate of bisphenol-A
Ernest Alderson Edmonds
Thesis (Ph.D.) - University of Birmingham, Dept. of Physics.
An extremely efficient flame retardant with low water solubility has been developed for bisphenol-A based polycarbonate. Potassium trimethylsilylbenzenesulfonate (KTSS) combining trimethylsilyl and sulfonate groups in its molecule is 7 times less water soluble and 5 times more effective in flame retardancy than potassium. enhancing the stability of polymers to radiation-induced effects. Sun of the Chanchun Institute of Applied Chemistry, China, has made a series of important advances in demonstrating new approaches to improving radiation resistant properties of polymers. Both the phenomena and ideas are new. One approach is by formation of network.
In this investigation, the degradation mechanisms of Bisphenol A Polycarbonate (BPA-PC) plates under blue light radiation are studied. The BPA-PC plates are used both in light conversion carriers in LED modules and encapsulantes in LED packages. Optical degradation of the products is mainly due to the degradation of BPA-PC encapsulants under blue light radiation. The effects of oxygen plasma treatment and the subsequent air exposure on the surface composition and properties of bisphenol A polycarbonate (BPA-PC) were analysed by X-ray photoelectron spectroscopy (XPS), ellipsometry, static time-of-flight secondary ion mass spectrometry (ToF-SIMS) with principal component analysis (PCA) and nanoindentation.
Abstract: Polycarbonate, which is a polymer plastic, is found in many bottles and food packaging around the world. However, because Bisphenol A is used in the processing of it, there is a potential danger to humans. Bisphenol A is a molecule that is a hormone inhibitor and also mirrors the function of estrogen. The overall food contamination by Bisphenol A is unknown, but the nutrition/ health impact of this chemical is an important subject to be discussed for all individuals. The main aim of one study recently analyzed was to assess the reproductive impact of BPA leached from regularly available polycarbonate plastic containers.
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1. Introduction. In recent years there has been increasing interest in the effect of gamma-irradiation on the structure and properties of polymeric materials, because they have been used in several environments that involve ionizing radiation, as insulating materials in nuclear power generation stations, as well as medical supplies sterilizable by gamma by: Amorphous Brazilian bisphenol-A polycarbonate (Durolon) is used in medical supplies.
Upon gamma-irradiation it undergoes main chain scissions. The major consequences are a decrease in the molecular weight and a yellowness of the by: The main polycarbonate material is produced by the reaction of bisphenol A (BPA) and phosgene COCl 2. The overall reaction can be written as follows: The first step of the synthesis involves treatment of bisphenol A with sodium hydroxide, which deprotonates the hydroxyl groups of the bisphenol A.
(HOC 6 H 4) 2 CMe 2 + 2 NaOH → Na 2 (OC 6 H 4 Refractive index (n): – Bisphenol A polycarbonate was thermally degraded in a rheometer barrel at temperatures from to °C, and samples collected af 40, 60 and 80 min were analysed by gel permeation.
However, bisphenol A polycarbonate is susceptible to photodegradation under ultraviolet (UV) radiation, which causes breakdown of the material, leading to yellowing, loss of toughness and embrittlement.
In this paper, the authors look into the effects of UV on polycarbonate. Radiation crosslinking of bisphenol-A polycarbonate (PC) was carried out by the γ-irradiation of the polymeric films containing 5 and 2 wt % of bisphenol-A dimethacrylate (BPDMA) or triallyl cyanurate, respectively, as well as by the BPDMA grafting from acetone solution onto PC preirradiated in air.
The modified samples were analyzed for the sol/gel content, and the dependences of gel. The contribution of humidity to the photodegradation of a commercial bisphenol A polycarbonate (BPA PC), aged under QUV-A radiation for periods of up to h, at relative humidity values of 0. BPA or Bisphenol A is a synthetic chemical which was first synthesized in and was originally used to increase the growth of poultry and cattle.
During the s it was recognized as an artificial estrogen and was subsequently used for estrogen replacement in women.
bisphenol A, bisphenol a effects, bisphenol a epoxy resins, bisphenol a. The data show that during three microwave-heating cycles of a baby bottle made from polycarbonate, microwave radiation had no effect on the migration of BPA in water.
All levels found were well below the SML of mg/kg specified for BPA in the European Commission Directive /19/EC. Data show that during three microwave-heating cycles of a baby bottle made from polycarbonate, microwave radiation had no effect on the migration of bisphenol A into water from polycarbonate.
All levels found were well below the specific migration limit of mg kg −1 specified for bisphenol A in Commission Directive /19/EC. Bisphenol A (BPA) is an organic synthetic compound with the chemical formula (CH 3) 2 C(C 6 H 4 OH) 2 belonging to the group of diphenylmethane derivatives and bisphenols, with two hydroxyphenyl is a colorless solid that is soluble in organic solvents, but poorly soluble in water ( wt % at 83 °C).
BPA is a precursor to important plastics, primarily certain polycarbonates and. Bisphenol A (BPA), a colourless crystalline solid belonging to the family of organic compounds; its molecular formula is C 15 H 16 O 2.
BPA is best known for its use in the manufacture of polycarbonate plastics and epoxy resins, particularly those found in water bottles, baby bottles, and.
Background. BPA is an industrial chemical used to make polycarbonate, a hard, clear plastic, which is used in many consumer products. BPA is also found in epoxy resins, which act as a protective. Polycarbonate plastic contains Bisphenol A (BPA) as a key building block.
The estimated dietary intake of BPA from polycarbonate is more than times lower than the maximum acceptable daily dose for BPA, established by the U.S. Environmental Protection Agency. Bisphenol A (BPA) is a synthetic compound for hardening and clearing polycarbonate plastics.
BPA is mainly classified as an estrogen-like endocrine-disrupting chemical. In the last decade, attention has arisen in scientific communities that it is not safe to use this chemical in mainly polycarbonate plastics.
Exposure to BPA starts in prenatal period, which is the critical period for its. remainder of this discussion the term radiation will be used to mean both high-energy electrons and gamma rays except where an explicit distinc- tion is made. NO induced radioactivity arises in materials irradiated with 6oCo gamma radiation or with electrons of energies up to 5 MeV.
The Effects of Radiation. Bisphenol A (BPA), a monomer used in the manufacture of epoxy, polycarbonate, and polystyrene resins, is a xenoestrogen present in many consumer products. We investigated the effects of 2-week exposure to BPA, either alone or in combination with X-rays, on the induction of DNA damage in somatic cells of female mice in vivo.
Bisphenol-A polycarbonate has been commercially available since the s, and its use in medical devices dates from approximately that time. Possessing a broad range of physical properties that enable it to replace glass or metal in many products, polycarbonate offers an unusual combination of strength, rigidity, and toughness that helps.
THE EFFECTS OF ULTRAVIOLET RADIATION ON POLYCARBONATE s of UV on polycarbonate glazing. Abstract. Unstabilised bisphenol A polycarbonate samples were aged under UV radiation for periods of up to hours.
The samples were then characterised using FTIR/ATR, GPC, SEM, microscopy, light transmission and colour changes. Bisphenol A (BPA) is used to produce certain types of plastic that are used in thousands of formulations for myriad products.
Containers made with these plastics may expose people to small amounts of BPA in food and water. Medical devices and other more ubiquitous products, such as thermal paper coatings, also may contribute significantly to human exposure.
A Japanese translation of “Our Stolen Future”, a book about the endocrine disrupter effects of bisphenol A, was published in This publication caused great concern among users and consumers of polycarbonates around Disquiet has largely subsided since Q How are you cooperating with overseas polycarbonate and bisphenol A.
The various and widespread uses of polycarbonate (PC) polymers require a meaningful and environmentally friendly disposal method. In this study, depolymerisation of polycarbonate with water in a microwave reactor is suggested as a recycling method.
Hydrolysis was investigated in an alkaline (NaOH) solution using a phase-transfer catalyst. Irradiation effects of γ-radiation on the physical and electrical properties of polycarbonate (Makrofol-E(film has been studied to be able to investigate the dielectric response of irradiated polymers for a wide range of fluence and frequency.
The dielectric constant (ε') The loss tangent (tanδ), dielectric loss factor (ε''), the a.c electrical conductivity (σ) and the relaxation time.