Structure of tall oil fatty acid-based alkyd resins and alkyd–acrylic copolymers studied by NMR spectroscopy

One- and two-dimensional NMR spectroscopy was used to evaluate the structure of tall oil fatty acid (TOFA)-based alkyd resins and waterborne alkyd–acrylic copolymers. An increase in the functionality of the polyol that is used in the alkyd resin synthesis was found to increase the reactivity of the polyol towards the diacid compared with the TOFA, which causes the formation of more branched and higher molar mass alkyd resin structures. During the copolymerization, polyacrylate chains were grafted to the double bonds and allylic sites of the fatty acid chains in the alkyd resin. Butyl acrylate preferentially grafted to the double bonds, while methyl methacrylate tended to graft to the allylic position. High proportions of the double bonds remaining after copolymerization were crucial to the film formation of copolymers, because the chemical drying of copolymer films occurred by an autoxidation process.     

Exploiting degrees of inflectional ambiguity: Stem form and the time course of morphological processing.

The authors compared sublexical and supralexical approaches to morphological processing with unambiguous and ambiguous inflected words and words with ambiguous stems in 3 masked and unmasked priming experiments in Finnish. Experiment 1 showed equal facilitation for all prime types with a short 60-ms stimulus onset asynchrony (SOA) but significant facilitation for unambiguous words only with a long 300-ms SOA. Experiment 2 showed that all potential readings of ambiguous inflections were activated under a short SOA. Whereas the prime-target form overlap did not affect the results under a short SOA, it significantly modulated the results with a long SOA. Experiment 3 confirmed that the results from masked priming were modulated by the morphological structure of the words but not by the prime-target form overlap alone. The results support approaches in which early prelexical morphological processing is driven by morph-based segmentation and form is used to cue selection between 2 candidates only during later processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Bringing maker practices to school: tracing discursive and materially mediated aspects of student teams’ collaborative making processes

The present investigation aimed to analyze the collaborative making processes and ways of organizing collaboration processes of five student teams. As a part of regular school work, the seventh-grade students were engaged in the use of traditional and digital fabrication technologies for inventing, designing, and making artifacts. To analyze complex, longitudinal collaborative making processes, we developed the visual Making-Process-Rug video analysis method, which enabled tracing intertwined with social-discursive and materially mediated making processes and zoomed in on the teams’ efforts to organize their collaborative processes. The results indicated that four of the five teams were able to take on multifaceted epistemic and fabrication-related challenges and come up with novel co-inventions. The successful teams’ social-discursive and embodied making actions supported each another. These teams dealt with the complexity of invention challenges by spending a great deal of their time in model making and digital experimentation, and their making process progressed iteratively. The development of adequate co-invention and well-organized collaboration processes appeared to be anchored in the team’s shared epistemic object.

     

Synthesis and characterization of tall oil fatty acids-based alkyd resins and alkyd–acrylate copolymers

The polymerization and properties of environmentally friendly waterborne binders for wood coatings were studied. Conjugated and non-conjugated tall oil fatty acids-based alkyd resins were synthesized and further copolymerized via miniemulsion polymerization with acrylates (butyl acrylate and methyl methacrylate). The ratio between alkyd resin and acrylate monomers was varied and the effect on copolymerization and the copolymer binder properties, such as particle size, molecular weight, grafting of acrylate to alkyd resin and reaction of double bonds, were studied. It was observed that the use of MMA influenced on the degree of grafting of acrylate and monomer conversion because the steric hindrances prevent MMA to react with alkyd double bonds as eagerly as BA. The increasing amount of alkyd resin was noticed to decrease the polymerization rate. The research showed that it was possible to prepare stable hybrids, alkyd–acrylate copolymers, with varied chemical composition.