Spin Trapping Analysis of Radical Intermediates on the Thermo-Oxidative Degradation of Polypropylene.

The purpose of this study is to investigate the thermo-oxidative degradation behavior of polypropylene (PP) by comparing three types of pristine PP granules (consisting of homopolymer, random copolymer, and block copolymer) with their corresponding oxidized analogues. These analogues were intensely oxidized under oxygen at 90 °C for 1000 h by using the electron spin resonance (ESR) spin trapping method that can detect short-lived radical intermediates during the degradation. The degrees of oxidation could be evaluated by chemiluminescence (CL) intensity, which was related to the concentration of hydroperoxide groups generated in the PP chain.

Polyethyleneimine-crosslinked cellulose aerogel for combustion CO capture.

Polyethylenimine (PEI) will block the channel of pore when it was impregnated in the porous solid, limiting its practical application in CO adsorption. In this method, a novel polyethyleneimine-crosslinked cellulose (PCC) aerogel sorbent was prepared by the sol-gel process, hydrolysis reaction and crosslinking reaction. The specific surface area of porous PCC aerogel was still retained 234.

Irradiation of cellulosic pulps: understanding its impact on cellulose oxidation.

Different pulp samples were irradiated by three energy sources: plasma, electron beaming, and γ radiation. The effect of increased exposure to irradiation was studied by multidetector gel permeation chromatography with fluorescence labeling of carbonyl groups to quantify changes of the cellulose. Whereas plasma treatment had no effect, for gamma and electron beam the degradation primarily affects the high molar mass area.

Effect of electron beam irradiation on the structure and properties of electrospun PLLA and PLLA/PDLA blend nanofibers.

Poly(L-lactide) (PLLA) and a PLLA/poly(D-lactide) (PDLA) blend (50/50 wt.%) were electrospun into nanofibers. Electron beam (e-beam) irradiation of the electrospun PLLA and blend nanofibers was used as a method to alter their structures and surface properties.