Biobased carbon content of resin extracted from polyethylene composite by carbon-14 concentration measurements using accelerator mass spectrometry
An estimation procedure for biobased carbon content of polyethylene composite was studied using carbon-14 (14C) concentration ratios as measured by accelerated mass spectrometry (AMS). Prior to the measurement, additives and fillers in composites should be removed because they often contain a large amount of biobased carbon and may shift the estimation. Samples of resin with purity suitable for measurement were isolated from composites with a Soxhlet extractor using heated cyclohexanone. After cooling of extraction solutions, the resin was recovered as a fine semi-crystalline precipitate, which was easily filtered. Recovery rates were almost identical (99%), even for low-density polyethylene and linear low-density polyethylene, which may have lower crystallinity. This procedure could provide a suitable approach for estimation of biobased carbon content by AMS on the basis of the standard ASTM D 6866. The biobased carbon content for resin extracted from polyethylene composites allow for the calculation of biosynthetic polymer content, which is an indicator of mass percentage of the biobased plastic resin in the composite.
Co-cross-linking of bio-based multi-functional epoxide and bisphenol A diglycidyl ether with 2-ethyl-4-methylimidazole
Abstract A co-cross-linking reaction of bio-based multi-functional epoxides (1) derived from limonene oxide and bisphenol A diglycidyl ether (BPADE) in the presence of 2-ethyl-4-methylimidazole (EMI) as a cross-linker afforded the corresponding network copolymers (2) having the 10% thermal decomposition temperature (Td10) of 294.4 °C at maximum. Adhesive strength induced by 1, especially tetra-functional epoxide, and BPADE exhibited remarkably higher than that by BPADE alone.
Efficiently establishing concepts of inferential statistics and hypothesis decision making through contextually controlled equivalence classes.
Computerized lessons that reflect stimulus equivalence principles were used to teach college students concepts related to inferential statistics and hypothesis decision making. Lesson 1 taught participants concepts related to inferential statistics, and Lesson 2 taught them to base hypothesis decisions on a scientific hypothesis and the direction of an effect. Lesson 3 taught the conditional influence of inferential statistics over decisions regarding the scientific and null hypotheses. Participants entered the study with low scores on the targeted skills and left the study demonstrating a high level of accuracy on these skills, which involved mastering more relations than were taught formally. This study illustrates the efficiency of equivalence-based instruction in establishing academic skills in sophisticated learners.