Chang, Tianying published the artcileTerahertz dielectric spectroscopic analysis of polypropylene aging caused by exposure to ultraviolet radiation, Recommanded Product: Bis(2,2,6,6-tetramethylpiperidin-4-yl) decanedioate, the main research area is polypropylene aging UV radiation exposure terahertz dielec spectroscopic analysis; THz dielectric spectroscopy; polypropylene; ultraviolet aging.
Terahertz dielec. spectroscopy is shown to be an effective tool for bench-marking UV aging of polypropylene. In this, thin-film polypropylene samples exposed to standard artificial UV radiation in accelerated aging from 1 day to 30 days are closely monitored by a terahertz time-domain spectroscopy system and analyzed using an effective data processing method. It is found that the terahertz absorption of the polypropylene samples is generally weak and the terahertz dielec. constant varies slightly though discernibly during the aging process, with the refractive index decreasing slightly with increasing length of UV exposure. Nonetheless, the rate of variation of the polypropylene refractive index with increasing terahertz frequency exhibits a drastic inflection around the 15-days aging point and the rate changes suddenly from pos. value to neg. value. Based on this prominent and consistent THz dielec. spectroscopic feature of the aging process, an efficient judging criterion is established to distinguish the early-term, mid-term, and late-term phases as well as the degree of polypropylene UV aging, corresponding to the fundamental transformation of the polymer material from a nonpolar to a polar substance at a critical level of oxidation induced by UV radiation.
Polymers (Basel, Switzerland) published new progress about Absorptivity. 52829-07-9 belongs to class piperidines, name is Bis(2,2,6,6-tetramethylpiperidin-4-yl) decanedioate, and the molecular formula is C28H52N2O4, Recommanded Product: Bis(2,2,6,6-tetramethylpiperidin-4-yl) decanedioate.
Referemce:
Piperidine – Wikipedia,
Piperidine | C5H11N – PubChem