Reference

Polymeric N-substituted maleimide antioxidants

Polymeric N-substituted maleimide antioxidants. Dale, James A.; Ng, Steve Y. W. (Dynapol, USA). U.S. US 4078091 7 Mar 1978, 8 pp. (English). (United States of America). CODEN: USXXAM. CLASS: IC: A23D005-04. NCL: 426545000. APPLICATION: US 75-565168 4 Apr 1975. DOCUMENT TYPE: Patent CA Section: 35 (Synthetic High Polymers) Section cross-reference(s): 17 The N-substituted maleimides (I; R and R' = C1-5 alkyl; n = 2-2000) were prepd. and used as antioxidants, esp. for foods. Thus 2,6-di-tert-butyl-4-nitrophenol [728-40-5] was nydrogenated to give 2,6-di-tert-butyl-4-aminophenol [950-58-3] which was treated with maleic anhydride [108-31-6] to give N-(3,5-di-tert-butyl-4-hydroxyphenyl)maleamic acid (II) [36435-93-5]. Dehydration of II gave the maleimide [40937-74-4] which was polymd. in the presence of AIBN to give I (R = R' = CMe3)(III) [66643-11-6] (mol. wt. = 16,000). No changes occurred in III in acidic THF-water at 51.5° while basic incubation led to minor changes in mol. wt. distribution. Pendant group cleavage did not occur at 31% concn. in either medium.

Case studies of storage yellowing of white polyester sewing threads and the development of a laboratory test to simulate such yellowing

Case studies of storage yellowing of white polyester sewing threads and the development of a laboratory test to simulate such yellowing. Williams, D. J. (Org. Div., ICI PLC, Blackley/Manchester M9 3DA, UK). J. Soc. Dyers Colour., 100(9), 268-74 (English) 1984. CODEN: JSDCAA. ISSN: 0037-9859. DOCUMENT TYPE: Journal CA Section: 40 (Textiles) There was a lack of correlation between the 36,000 ppm N oxides test (a screening test proposed by McEwan and Murdoch (1981) involving exposing the textile sample to 36,000 ppm N oxides) and the storage yellowing or fading of white polyester sewing thread whitened with C.I. Fluorescent Brightener 199, sewed into a polyester blouse or cotton-polyester dress, wrapped in paper products, and stored in a polyethylene (I) [9002-88-4] film. The yellowing was not due to the interaction of N oxides with the original textile substrate or with the disperse fluorescent brightening agent present, but rather to the presence of 3,3',5,5'-tetra-tert-butyl-4,4'-stilbenequinone [809-73-4] derived from the interaction of atm. N oxides with the antioxidant BHT [128-37-0] which had migrated from the I packaging into the stage lubricant. The 3 factors required to cause storage yellowing are the presence of BHT, a stitch lubricant or finish for which BHT has affinity, and exposure of the garment to atm. N oxides. A proposed test for predicting package-induced yellowing of sewing threads involves warm storage of the thread in the presence of either BHT or 2,6-di-tert-butyl-4-nitrophenol [728-40-5].