Papers by Keyword: Average Molecular Weight

Abstract: Sulfonated cyclohexanone-formaldehyde resin (SCF) was synthesized using cyclohexanone and formaldehyde as raw materials, sodium sulfite as sulfonating agent. The composition of the SCF resin was characterized by FTIR and 13C NMR, and the possible mechanism for formation of the resin was suggested. The effects of reaction parameters, such as ratio of formaldehyde and cyclohexanone, the amount of sulfonating agent, as well as reaction temperature and pH, on the viscosity and average molecular weight were investigated. The results showed that the optimum reaction conditions was that the ratio of reactant was n (formaldehyde):n (cyclohexanone):n (sodium sulfite) = 2.0:1.0:0.7, and pH value of the system was 10 at 90°C temperature. The average molecular weight of the resulted resin was 58392.

Abstract: Hot-embossing experiments were conducted on poly (methyl methacrylate) orthogonal arrays with base widths of 1μm, 3μm, 5μm, 10μm, and 50μm. The relationship between the base width with respect to average molecular weight and number average molecular weight of micropattern were also investigated. It was discovered that the average molecular weight and number average molecular weight decreased as the base width increased.

Abstract: Pyrolysis of high density polyethylene (HDPE) to polyethylene wax (PEW) in a 1 L continues stirred-tank reactor (CSTR) was studied at 360-420 °C with 5-240 min, yield of PEW was discussed and the properties such as the drop melting point and average molecular weight of wax were determined. The PEW had a melting point of 104-120 °C, and an average molecular weight of around 3000 with a good dispersity at 673 K. Moreover, the composition of wax determined by fourier transform infrared spectroscopy (FT-IR) indicated that it was less branched than commercial waxes.