On the Sieve Analysis of Tea

Condensation of Arylboroxine Structures on Lewis Basic Copolymers as a Noncovalent Strategy toward Polymer Functionalization

“…Although the exact mechanism responsible for the thermal decomposition in these functionalized copolymers remains unclear, preliminary TGA-mass spectrometry analysis indicates that the initial fragmentation of the arylboroxine at 220 °C36 may be generating radicals capable of catalyzing the degradation of the polystyrene/4-VP at temperatures below 400 °C. 37 In conclusion, we have demonstrated that the incorporation of arylboroxines into PS/4-VP random copolymers is synthetically straightforward, increases polymer T g , and lowers the onset temperature of thermal degradation. Current and future work will be directed toward expanding the structural and functional complexity of the arylboronic acids used in the functionalization reaction and further understanding the role of arylboroxines in modifying the properties of PS/4-VP random and block copolymers.…”

“…The parent polymer shows no significant weight loss until 400 °C, consistent with other reports of the thermal degradation of polystyrene and poly(4-vinylpyridine) homopolymers. − Degradation is observed at increasingly lower temperatures as the amount of incorporated 4-fluorophenylboroxine increases. Although the exact mechanism responsible for the thermal decomposition in these functionalized copolymers remains unclear, preliminary TGA−mass spectrometry analysis indicates that the initial fragmentation of the arylboroxine at 220 °C may be generating radicals capable of catalyzing the degradation of the polystyrene/4-VP at temperatures below 400 °C …”

Essential oils and related products

“…The aroma components of green and black tea were compared by Hara and Kubota (171). Kharebava et al (221) investigated the volatile oil from black tea.…”