Renata Jovanovic

Emulsion‐Based Pressure‐Sensitive Adhesives: A Review

Abstract Pressure sensitive adhesives (PSAs) adhere instantaneously to a variety of surfaces upon application of slight pressure and can be obtained using different technologies. Increasing environmental concerns and regulations are the major driving forces for the development of emulsion‐based PSAs. Given the number of factors affecting the emulsion polymerization process and versatility of emulsion‐based polymers, there is a need to identify and model those factors that significantly influence particular PSA applications. In this review, factors such as emulsion polymerization components, latex rheology, and film formation are examined in light of their relevance to adhesion. In addition, the body of knowledge related to measurement methods, design factors, and modeling of each of the three major PSA performance characteristics (i.e., tack, peel strength, and shear strength) is reviewed with a particular emphasis on emulsion‐based PSAs.

In‐Line Monitoring of Butyl Acrylate/Vinyl Acetate Emulsion Copolymerizations Using ATR–FTIR Spectroscopy

A study of butyl acrylate/vinyl acetate (BA/VAc) batch emulsion copolymerization was carried out in a 5L stainless steel and a 1.2L glass reactor. Conversion and copolymer composition were monitored off‐line using standard techniques (i.e. gravimetry, gas chromatography and 1H‐NMR spectroscopy) and in real‐time, in situ using Attenuated Total Reflectance‐Fourier Transform Infrared (ATR–FTIR) spectroscopy. The basis for in‐line polymerization monitoring using ATR–FTIR spectroscopy in this work was the change of the intensity of characteristic peaks of monomers with time. Real‐time peak profiles (absorbance vs. time) of the monomers were used to calculate conversion and copolymer composition for real‐time ATR–FTIR monitoring. The data obtained using the ReactIR™ 1000 reaction analysis system showed good agreement with data obtained using standard techniques. In addition, there were indications that this technique can be used for early detection of catastrophic coagulation inside a reactor. The limitations in real‐time monitoring of BA/VAc emulsion polymerizations using ReactIR™ 1000 were also investigated.

Computer-Based Study Skills Training: The Role of Technology in Improving Performance and Retention.

The influence of computer-based study skills training on the academic performance of first year chemical engineering students was investigated. Students were randomly assigned to a treatment group that used R.E.S.U.L.T.S.© study skills software and a comparison group that did not use the software. Pre-university and first-term university academic performance measures of these groups were compared. Student goals, use of time, self assessments, and feedback were also examined. Although improvements in post-treatment performance were observed, pre-treatment group differences were also found to exist. Despite this limitation, the findings provide useful insights concerning what helps students learn. They also raise questions for future research.