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People wear clothes for warmth, survival and necessity in modern life, but in the modern era, eco-friendliness, shortened production times, design and intelligence also matter. To determine the relationship between data series and verify the proximity of each data series, a gray relational analysis, or GRA, is applied to textiles, where seamless bonding technology enhances the bond between components. In this study, a polyurethane prepolymer, 2-hydroxyethyl acrylate (2-HEA) as an end-capping agent and n-octyl acrylate (ODA) as a photoinitiator were used to synthesize a dual-curing polyurethane hot-melt adhesive. Taguchi quality engineering and a gray relational analysis were used to discuss the influence of different mole ratios of NCO:OH and the effect of the molar ratio of the addition of octyl decyl acrylate on the mechanical strength. The Fourier transform infrared spectroscopy (FTIR) results showed the termination of the prepolymer's polymerization reaction and the C=O peak intensity at 1730 cm−1, indicating efficient bonding to the main chain. Advanced Polymer Chromatography (APC) was used to investigate the high-molecular-weight (20,000–30,000) polyurethane polymer bonded with octyl decyl acrylate to achieve a photothermosetting effect. The thermogravimetric analysis (TGA) results showed that the thermal decomposition temperature of the polyurethane hot-melt adhesive also increased, and they showed the highest pyrolysis temperature (349.89 °C) for the polyhydric alcohols. Furthermore, high peel strength (1.68 kg/cm) and shear strength (34.94 kg/cm2) values were detected with the dual-cure photothermosetting polyurethane hot-melt adhesive. The signal-to-noise ratio was also used to generate the gray relational degree. It was observed that the best parameter ratio of NCO:OH was 4:1 with five moles of monomer. The Taguchi quality engineering method was used to find the parameters of single-quality optimization, and then the gray relation calculation was used to obtain the parameter combination of multi-quality optimization for thermosetting the polyurethane hot-melt adhesive. The study aims to meet the requirements of seamless bonding in textile factories and optimize experimental parameter design by setting target values that can effectively increase production speed and reduce processing time and costs as well. [ABSTRACT FROM AUTHOR]

BACKGROUND Based on the biorefinery concept, the main focus of this work was the increase in value of spent coffee grounds via an acid liquefaction process using polyhydric solvents in the presence of sulfuric acid, at moderate temperature. For that purpose the effect of temperature, sulfuric acid concentration and time on biomass conversion was studied using design of experiments combined with statistical analysis. RESULTS The ANOVA results (95% confidence level) showed that temperature is the factor with most influence on biomass conversion, within the studied range, while reaction times above 40 min don't seem to bring significant advantages. The maximum conversion obtained in this study was 70 wt% which was achieved at 160°C, 4 wt % of catalyst and 80 min. The polyol obtained using these conditions presented a hydroxyl number value of 199 mg KOH/g polyol and a viscosity of 390 cP, at 25°C. CONCLUSION This work showed that it is possible to convert spent coffee grounds into liquid polyols via an acid liquefaction process at moderate temperature and autogeneous pressure. These polyols have similar properties to those of petroleum-based polyols typically used in the polyurethane foam industry. © 2014 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Polyurethane (PU) and polyhydric alcohols composites were successfully prepared to be used as coating materials for fabrics. The effects of various polyhydric alcohols on the PU composites properties have been investigated. The tensile strengths, glass‐transition temperatures, thermal‐mechanical properties, and swelling capacities of the PU/polyhydric‐alcohol‐blended films are described in detail, along with their surface and cross‐sectional morphologies. The tensile strengths and glass‐transition temperatures of the PU/polyhydric‐alcohol‐blended films were found to decrease remarkably with increasing polyhydric‐alcohol concentration. The swelling capacities and porosities of the PU/poly(propylene glycol) (PPG)‐blended and PU/glycerol‐blended films were observed to increase with increasing PPG or glycerol concentration. However, the poly(ethylene glycol) (PEG) concentration in the PU/PEG‐blended film did not significantly affect its properties. The air and water‐vapor permeability of nonwoven nylon fabrics coated with PU/PPG and PU/glycerol increased with increasing PPG or glycerol contents, while those coated with PU/PEG were unaffected by PEG content. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47429. [ABSTRACT FROM AUTHOR]