Identification of styrene copolymers and a terpolymer by second derivative ultraviolet spectroscopy

A method for distinguishing styrene copolymers and a terpolymer by second derivative ultraviolet spectroscopy will be described. The polymers were dissolved in chloroform except for one which was dissolved in 2-butanone. Concentrations of about 5 g/L were used. The polymer solutions were applied to the removable windows of divided, quartz cells and were allowed to dry to a thin film. The ultraviolet region was scanned from 300 to 230 nm. Then thinner films were used, and the 240–200 nm region was scanned. The second derivative spectra that resulted could be distinguished easily. This technique allows rapid, sample preparation and identification of these copolymers and the terpolymer.     

Use of Fourier transform infrared and second derivative ultraviolet spectrometry in determining polystyrene–poly(4‐vinylpyridine) blend composition

Polymer blend usage has increased in recent years as the blends provide a convenient means for modifying polymer properties. It is often necessary to be able to determine the percentages or ratios of polymers present in a blend. One blend of interest is the immiscible blend of polystyrene (PS) and poly(4‐vinylpyridine) (P4VP). The percentages were determined by two methods: Fourier transform infrared (FTIR) spectroscopy and second derivative ultraviolet (UV) spectroscopy. The peak ratio versus percentage polymer technique was used in both methods. For FTIR, the ratio of the absorbance values of the out‐of‐plane C? H bending vibration of P4VP at 822 cm^?1 and the aromatic C ? C stretch for PS at 1493 cm^?1 were ratioed. For derivative UV, the vibrational structure of the aromatic secondary bands was used: 269 nm minimum for PS and the 271 nm maximum for P4VP. Both methods gave excellent and comparable results. The derivative UV determination had the advantage of requiring less sample due to its greater sensitivity. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2422–2426, 2005     

Fourier transform infrared and second derivative ultraviolet spectrometry in determining polystyrene‐poly(4‐methylstyrene) blend composition

Polymer blend usage has increased in recent years as the blends provide a convenient means for modifying polymer properties. It is often necessary to determine the percents or ratios of the polymers present in a blend. One blend of interest is the immiscible blend of polystyrene (PS) and poly(4‐methylstyrene) (P4MS). The percentages were determined by two methods: Fourier transform infrared (FTIR) spectroscopy and second derivative ultraviolet (UV) spectroscopy. The peak ratio versus percent polymer technique was used in both methods. For the FTIR, the ratio of the absorbance values for the out‐of‐plane C? H para‐substituted bending vibration of P4MS at 813 cm^?1 and the out‐of‐plane monosubstituted C? H bending vibration for PS at 757 cm^?1 were ratioed. For derivative UV, the vibrational structures of the aromatic secondary bands were used: the 269 nm minimum for PS and 275 nm minimum for P4MS. The derivative UV method gave considerably better results and also had the advantage of requiring less sample due to its greater sensitivity. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3400–3403, 2006     

不同处理条件对菜籽粕中酚类物质的影响

研究了不同处理条件地菜籽粕中酚类物质的影响，菜籽粕经不同压力、温度、湿度和氨水－甲醇－正己烷溶液处理后酚类物质含量有不同程度的下降，初步试验结果表明：添加１０％，１５％２０％水量时，酚类物质含量分别减少３５％、３６％、３８％。在５０和１００ｋＰａ加压处理时，酚类物质含量分别减少４９％，４１％。在温度１００％，１１５℃时酚类物质含量分别减少３７％，３９％，经过氨水－甲醇－正己烷溶液处理后酚类物质含量