June 2019 Abstracts

Country-level Life Cycle Assessment of Carbon Footprint in Processing of Bovine Upper Leather

by Mianhong Chen, Youdan Duan, Liming Dong, Min Chen and Haiming Cheng

Leather-making processes have achieved great improvements in reducing environmental pollution all over the world. In this study, we collected the data from the tanneries in five countries on the material flow to quantify and analyze the carbon footprint of leather-making process, based on the Life Cycle Assessment with two impact assessment methods that characterize the impact of climate change (IPCC 2013 GWP 100 years and GHG Protocol). To process 1000 kg of raw hides, tanneries in Chile, China, India, Italy, and Spain emitted 882, 1180, 1608, 1198, and 755 kg of carbon dioxide equivalent (CO2Eq), respectively. The carbon footprint of 1 kg of finished leather for shoe upper in five countries ranges from 3.41 to 6.30 kg CO2Eq. The average power consumption was the largest factor causing carbon emissions, followed by the consumption of acrylic resin, and chromium tanning agent. Carbon footprint analysis suggested that enzyme-assisted beamhouse and recycling of the liming float and the tanning float can effectively reduce carbon emissions during the leather-making process. This study will lay the foundation for the carbon footprint research of the downstream products of leather (shoes, apparel industry, etc.).

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Synthesis and Leather Application Properties of a Carboxylated Graphene Oxide Modified Waterborne Polyacrylate Leather Finishing Agent

by Shuangquan Lai, Yong Jin, Liangjie Shi and Weining Du

Carboxylated graphene oxide (GO-COOH), prepared by the reaction of bromoacetic acid with the hydroxyl and epoxy groups on the graphene oxide (GO) layers, was blended into a poly(ethyl acrylate) (PEA) emulsion and a PEA emulsion based polyacrylate leather finishing agent respectively, to prepare PEA/GO-COOH composite emulsions and GO-COOH modified waterborne polyacrylate leather finishing agents. The consequence of the amount of GO-COOH on the properties of the PEA film and related leather coatings were systematically investigated. The results indicate that stable GO-COOH dispersed composite emulsions were generated leading to homogeneously dispersed composite films. With an increase in the GO-COOH amount from 0 wt% to 0.5 wt%, the tensile strength increased by 106.2%. Additionally, TGA results demonstrated an improvement of the thermal stability of PEA film after modified with GO-COOH. Most importantly, the folding resistance and rubbing fastness properties of leather finished with GO-COOH modified polyacrylate leather finishing agents were improved proportionate to the GO-COOH amount. Therefore, the GO-COOH modified waterborne polyacrylate leather finishing agent possesses improved performances and likely offers beneficial leather finishing application properties.

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Graphene Oxide Grafted Maleic Anhydride Vinyl Acetate Co-polymer and its Enhancement of Flame Retardant and UV-resistance of Retanned Leather

by Yazhou He, Zhenyu Zhang, Haojun Fan, Yi Chen and Jun Yan

Maleic anhydride grafted graphene oxide (GOMA) monomer was prepared by modifying the graphene oxide (GO) with hexachlorocyclotriphosphazene (HCCP), ethylenediamine (ETA) and maleic anhydride (MA). Then a polymeric retanning agent, abbreviated as poly(GOMA-MA-VA) was synthesized from GOMA, MA and vinyl acetate (VA) by free radical polymerization. The structures of GOMA and poly(GOMA-MA-VA) were characterized by Fourier transform infrared (FTIR) spectroscopy, Raman and X-ray photoelectron spectroscopy (XPS), simultaneously, the flammability, UV-resistance as well as the thermal stability and mechanical properties of re-tanned leathers were also investigated. Results show that GO grafted by polymer presents well dispersing stability and can penetrate into collagen fibers to form strong combination with fibers. Furthermore, this novel multifunctional retanning agent can efficiently improve the flame retardance, ultraviolet (UV) resistance, thermal stability and mechanical properties of resultant leather.

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Investigation of the Synthesis of a Novel Glycidyl Ether-amine Epoxy Tanning Agents and their Tanning Performance

by Xiaoyan Pang, Zhiwen Ding, Wei Ding, Xiao Xiao, Xuepin Liao and Bi Shi

Isophorone diamine (IPDA) and epichlorohydrin (ECH) were used to fabricate the epoxy tanning agents, and polyalcohol compounds (glycerol, polyethylene glycol, ethylene glycol) were employed to introduce the ether bonds into the epoxy tanning agents to improve their compatibility with water. The prepared epoxy tanning agents were named IGE, IPE and IEE for the introduction of glycerol, polyethylene glycol and ethylene glycol, respectively. FT-IR and 1H NMR analysis indicated that epoxy groups, ether bonds and hexatomic rings were successfully introduced into IGE, IPE and IEE. The tanning performances of the epoxy tanning agents were further evaluated in water, ethanol-50 (50% of ethanol in water) and ethanol-95 (95% of ethanol in water) medium, which suggested that ethanol-50 was the most favorable one for the epoxy tanning agents. The IGE tanned leather exhibited the highest shrinkage temperature of 83ºC in ethanol-50 due to its low viscosity, high epoxy value and wide molecular dispersion. Morphology observation indicated that the IGE tanned leather exhibited better dispersion of fiber network than that of IPE and IEE tanned leathers. These results illustrated that IGE was an appropriate tanning agent in water-ethanol medium, which could be considered as a candidate for the organic tanning agents.

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