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Bisphenol A (BPA) is widely used as a color developer in thermal paper. Thermal paper is ubiquitous in daily life due to its use in cash register receipts, so opportunities for human contact abound. For this study, 10 blank cash register receipts were obtained from businesses in suburban Boston. BPA was extracted and analysis of concentration was performed using gas chromatograph/flame ionization detector. In some receipts, BPA was not detected but in others it was as high as 19 mg for a 12-inch long receipt, which is in line with concentrations indicated in patents. This study is intended to highlight the potential for human exposure to BPA as well as the ease with which exposure may be reduced through the use of BPA-free thermal paper. [ABSTRACT FROM AUTHOR]

Photocrosslinking of thymine-based water-soluble polymer films was investigated at varying preparation conditions. Adding salt or decreasing the pH of the solution from which the films were cast resulted in the decreased efficiency of photoimmobilization, while increasing the pH was found to increase the photoimmobilization efficiency. A mechanistic rationale for the observed effects is proposed. [ABSTRACT FROM AUTHOR]

Dissolution kinetics of dyes entrapped in photocrosslinked polymer matrix were investigated. Films containing thymine‐based bioinspired photopolymers and non‐toxic dyes were deposited on the polyethylterephthalate (PET) substrate from aqueous solutions. The films were cured by exposure to various UV‐irradiation doses (λ=254 nm) and developed in a weakly acidic aqueous medium. The UV‐Vis spectra of the films before and after curing and development were taken and the intensities of the bands corresponding to the absorbance of the respective dyes entrapped in the films were monitored for a variety of irradiation doses, development times, polymer compositions and two different dyes. [ABSTRACT FROM AUTHOR]

The immobilization of thymine‐containing copolymers of vinylphenylsulfonate (VPS) and vinylbenzylthymine (VBT) on a nonreactive substrate has been investigated. These polymers are environmentally benign, water‐soluble and when irradiated with low levels of UV light undergo a 2π+2π photodimerization reaction of the thymine moieties. These photoinduced dimers form a crosslinked network that renders the polymer significantly less soluble in water. Consequently the irradiated polymer is immobilized on the substrate, allowing removal of unexposed regions by simple aqueous wash. Visualization of the photoresist is done by “toning” the remaining anionic copolymer with the cationic dye methylene blue. By evaluating the color density of the crosslinked, toned films by UV‐Vis spectroscopy, this report describes the impact of copolymer composition and curing conditions on polymer photoreactivity. Mechanistic rationale is proposed. [ABSTRACT FROM AUTHOR]

The author talks about the growth of the green chemistry community. He looks back on the state of the chemical industry in 2008. According to him, the transition of green chemistry to an economic and business imperative integrated throughout research, development and manufacturing has been realized across various fields. He notes that green chemistry is regarded as a mechanism to address environmental hazards, an opportunity to create workforce development and a pathway to science literacy in classrooms.