Graphene Oxide Functionalized Cottonseed-Lignin Resin with Enhanced Wet Adhesion for Woody Composites Application

With rising interior air pollution, health, and food shortage concerns, wood adhesives derived from non-food sustainable materials have therefore attracted considerable attention. Here we developed an eco-friendly cottonseed-lignin adhesive consisting of non-food defatted cottonseed flour (DCF), alkali lignin (AL), and graphene oxide (GO). The cation-π interaction, and hydrogen and covalent bonds between AL@GO and DCF collectively enhanced the cross-linking structure of the cured cottonseed-lignin adhesive, based on the Fourier-transform infrared spectroscopy, thermogravimetric analyses, scanning electron microscopy, and sol-gel tests. The high performance of the developed cottonseed-lignin adhesive was evidenced by its increased wet/dry shear strength and decreased rheological properties before curing and improved thermal stability and decreased soluble substances after curing. Particularly, the highest wet shear strength of poplar plywood bonded with cottonseed-lignin adhesive was 1.08 MPa, which increased by 74.2 and 54.3% as compared to the control and requirement of the Chinese standard GB/T 9846-2015 for interior plywood (≥0.7 MPa), respectively. The technology and resultant adhesives showed great potential in the preparation of green woody composites for many applications.

Effects of enzymatic, sprouting and solvent methods on free and total gossypol reduction, oil content, flour yield and crude protein content

Use of cottonseed as protein source for food application and monogastric animals are restricted due to the presence of polyphenolic toxic content known as gossypol. Reduction of gossypol and improving crude protein content in cottonseed flour may increase its utility for feed and food industries. The present study aims to analyze the influence of three individual methods viz., sprouting method, enzymatic method and solvents method on free and total gossypol content, crude protein content, oil content and flour yield. Enzymatic treatments were performed using culture candida tropicalis, saccharomyces cerevisiae and combinations of both whereas for solvent treatments four different solvents namely acetone, ethanol, methanol and iso-propanol with their four different levels (70-100%) were applied. Results of this study revealed that 70% aqueous acetone showed maximum free gossypol reduction (97%), crude protein content (65.6%), oil content 31.3 % and 57% flour yield was observed. However, total gossypol reduction was only 51%. Other side, enzymatic treatment based on candida tropicalis found more effective in terms of total gossypol reduction (73%), however crude protein content was recorded only 39.4%.

Dietary cottonseed consumption induced subfertility in male and female rats: a potent eco-friendly rodenticide compound

Effects of cottonseed flour in male and female rats’ fertility based on hormonal and histomorphometry changes were studied. Sixty-four Sprague-Dawley adult male and female rats were randomly divided into control and treatment groups. Treatment group was received diets containing cottonseed flour for 35 days. Control group was given standard rat food. Body and testis weights, epididymis semen evaluation indices and serum sex steroid hormones were determined. Histomorphometry alterations of testes and ovary were evaluated. Then, normal female and male rats were mated by rats in both groups and after 35 days, number of pups was measured. However, there was no significant difference in whole body and testes weights, sperm concentration and viability between the control and treatment groups, respectively. Moreover, sperm motility in the treatment rats was significantly lower than the control group. Serum hormones alterations were not significant, but histomorphometry evaluations of testes showed significant changes in the testis structures after chronic consumption of cottonseed flour. In the female rats, body weight did not have significant difference between the treatment and control groups. Histomorphometry data in female ovary showed significant reduction of primary follicle volume and number in the treatment group against control. Follicle stimulating hormone showed insignificant reduction in the treatment group. Number of pups was significantly reduced in the female rats fed by cottonseed flour. Cottonseed flour in rat diet had adverse effects on rat reproduction. Therefore, it can be used as an efficient product for control of the rat population as a natural rodenticide agent.

Investigation of a formaldehyde-free cottonseed flour-based adhesive for interior plywood

A new formaldehyde-free wood adhesive, primarily composed of defatted cottonseed flour (CF) and polyamine-epichlorohydrin (K736) resin, was investigated for the preparation of interior plywood. Sodium hydroxide was an essential component of the adhesive. The effects of pH values of the CF-K736 adhesive, the CF/K736 weight ratio on the pot life of the adhesive, and the water resistance of the resulting plywood panels were investigated in detail. The hot-pressing temperature and time were optimized in terms of the water resistance of the resulting plywood panels. The resulting 5-ply plywood panels met the industrial water resistance requirements for interior application under the following conditions: pH > 11, CF/K736 weight ratio in the range of 8/1 to 5/1, hot-press temperature ≥ 120 °C, and hot-pressing time > 4 min. The pot life of the adhesive was approximately 3 h when the pH was 12 and the CF/K736 weight ratio was 8/1. The curing mechanism of the adhesive is discussed.

Environment-Friendly Cottonseed Protein Bioplastics: Preparation and Properties

A novel class of environmentally friendly protein-based bioplastics—cottonseed protein plastic sheets (CP-sheets)—were prepared by compression molding in the presence of cottonseed flour as main raw material, aldehydes as crosslink agent and glycerol as plasticizer. FTIR, TGA, tensile tests and water uptake measurements were applied to characterize the structure, thermal stability, mechanical properties and water absorption of the CP-sheets. It was found that the crosslinked CP-sheets (CP-FA, CP-GX and CP-GA) showed higher thermal stability and tensile properties, less water uptake than the CP-sheet withou crosslinking treatment (CP-0CL). The CP-sheets with good thermal, mechanical and hydrophobic properties are emerging and promising bioplastics for potential applications in food packaging as well as flower planting.

Glycosylated flavones as selective inhibitors of topoisomerase IV.

Three flavonoids which promoted Escherichia coli topoisomerase IV-dependent DNA cleavage were isolated from cottonseed flour and identified as quercetin 3-O-beta-D-glucose-[1,6]-O-alpha-L-rhamnose (rutin), quercetin 3-O-beta-D-galactose-[1,6]-O-alpha-L-rhamnose, and quercetin 3-O-beta-D-glucose (isoquercitrin). The most active one (rutin) also inhibited topoisomerase IV-dependent decatenation activity (50% inhibitory concentration, 64 microg/ml) and induced the SOS response of a permeable E. coli strain. Derivatives of quercetin glycosylated at position C-3 were shown to induce two site-specific DNA cleavages of pBR322 DNA, which were mapped by DNA sequence analysis to the gene encoding resistance to tetracycline. Cleavage at these sites was hardly detectable in cleavage reactions with quercetin or fluoroquinolones. None of the three flavonoids isolated from cottonseeds had any stimulatory activity on E. coli DNA gyrase-dependent or calf thymus topoisomerase II-dependent DNA cleavage, and they were therefore specific to topoisomerase IV. These results show that selective inhibitors of topoisomerase IV can be derived from the flavone structure. This is the first report on a DNA topoisomerase inhibitor specific for topoisomerase IV.