• Textile Coloration and Finishing
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• v.17 no.3 s.82
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• pp.16-25
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• 2005

In this research, we investigated hydrolysis of the ester crosslinking on cotton fabric treated with polymer of maleic acid(PMA), citric acid(CA) and combination of polymer of maleic acid and citric acid using Fourier transform infrared spectroscophy. The rate of hydrolysis of the ester crosslinkage increased with pH regardless of the type of polycarboxylic acid used and even after hydrolysis for 256 hour in pH 13_4 solution, the treated fabric retained $10-20\%$ ester crosslinkage. The durability to alkaline hydrolysis of the ester crosslinkage formed by CA was lower than that of by PMA and combination of poly(maleic acid) and citric acid indicating that the ester formed by CA on the cotton fabric is more susceptible to hydrolysis than that formed by PMA and combination of PMA and CA. The total amount of ester and polycarboxylic acid molecules removed from fabric increased with increasing hydrolysis time but the rate of hydrolysis of ester linkage were higher than that of removal of polycarboxylic acid molecule from the fabric. The characteristic of hydrolysis of fabric treated with combination of PMA and CA was related with the mixing ratio of PMA and CA in treating fabric.

• Textile Coloration and Finishing
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• v.15 no.4
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• pp.24-31
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• 2003

In this research, we applied FT-IR spectroscopy to study the hydrolysis of the ester-crosslinking formed by various polycarboxylic acids on the cotton fabric. We observed the following; (1) the ester-crosslinking is less durable to hydrolysis than ether-crosslinking under all conditions; (2) the ester-crosslinking formed by polycarboxylic acids having more than three carboxyl groups, such as butanetetracarboxylic acid (BTCA), are substantially more durable to hydrolysis than the acids having two or three carboxyl groups, such as maleic and citric acid; (3) alkaline conditions drastically accelerate the hydrolysis of both urea- and ester-crosslinking; and (4) the ester-crosslinking formed by poly(maleic acid) is more resistant to hydrolysis at alkaline conditions than BTCA. (5) polycarboxylic acid molecules were removed from the fabric at same rate as the hydrolysis of the ester linkage. FT-IR spectroscopy has proved to be a useful analytical technique for evaluating the hydrolysis of the crosslinked cotton fabric.

• Textile Coloration and Finishing
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• v.21 no.3
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• pp.1-9
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• 2009

Polycarboxylics acids are used as crosslinking agents for cotton cellulose to produce durable finished press cotton fabric. It has been observed that the strength of the cotton fabric treated with polycarboxylic acids showed significant reduction as a result of the crosslinking process. The effect of acid-catalyzed depolymerization on the tear strength of cotton fabric is investigated by evaluating the cotton fabric treated by succinic acid, which does not crosslink cotton cellulose and form little ester on the cotton fabric. We find that the tear strength of cotton fabric treated with succinic acid decreases at elevated temperature due to acid-catalyzed depolymerization of cellulose. The magnitude of fabric strength reduction increases as the acid concentration increases. At a constant acid concentration, it increases as the curing temperature and time increases. It decreases as the pH of the acid solution increases. We also find that the dissociation constant of an acid also has a significant effect on the fabric strength reduction. The magnitude of fabric tear strength reduction increases as the acid dissociation constant decreases.

• Journal of Radiation Industry
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• v.4 no.1
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• pp.19-23
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• 2010

Vinyl ester (VE) resins, introduced in the late 1960s, have made large strides in reinforced plastics applications as adhesive and matrix materials on their appropriate mechanical performance characteristics in the glassy state. Generally, VE resins are a group of dimethacrylate resins based on bisphenol A type epoxy resin. They exhibit easy handling properties as well as good resistance to most chemical agents due to their mechanical and thermal properties. In this study, the effects of curing methods of vinyl ester resins on gel contents, flexural strength and dynamic mechanical properties were investigated. Thermal curing (room temperature, $80^{\circ}C$) and electron beam curing were used to crosslink a VE resin/styrene complex (65/35 wt%) with methyl ethyl ketone peroxide (MEKPO) as a catalyst and an 8 wt% cobalt naphthenate in styrene solution as a accelerator. For the samples, gel contents as well as flexural strength and dynamic mechanical properties were characterized and compared by soxhlet apparatus, universal testing machine (UTM) and dynamic mechanical analysis (DMA). As a result, the electron-cured VE resin was confirmed as a better condition than those for gel contents, flexural strength and dynamic mechanical properties, respectively.