The employment of sustainable chemicals, such as citric acid, represents a possibility for the development of textile dyeing processes. This study aimed to analyze the possibility of replacement of acetic acid (common...The employment of sustainable chemicals, such as citric acid, represents a possibility for the development of textile dyeing processes. This study aimed to analyze the possibility of replacement of acetic acid (commonly used in textile processing) by citric acid in polyester and polyamide 6 dyeing processes. The utilization of citric acid as leveling agent for disperse dyestuffs was also investigated. Dyeing processes in turquoise color for these fabrics were performed employing citric and acetic acid. Color differences between dyeing processes and color fastness to water were evaluated. All the color dyeing differences were not significant and there was no transference in color fastness tests (grade 5). Otherwise, the differences among polyamide dyeing processes could be related to the efficiency of citric acid solution as sequestering agent. Notwithstanding citric acid to be more expensive than acetic acid and the need of previous dissolution by stirring, it could be advantageous for some formulations.展开更多
Blends of polyamide (Nylon 66) with two different kinds of liquid crystalline polyesters were studied in all the composition range. Homogeneous samples were obtained by coprccipitation from 2 wt%. solution of blends. ...Blends of polyamide (Nylon 66) with two different kinds of liquid crystalline polyesters were studied in all the composition range. Homogeneous samples were obtained by coprccipitation from 2 wt%. solution of blends. The thermal properties, crystallinity and morphology of these blends were studied by using DSC, polarizing microscopy, and scanning electron microscopy. The phase transition and morphology of the blends are markedly-influenced by the composition of liquid crystalline polyesters. The mechanical behaviour of PHB/HNA-Nylon 66 blend was improved. although polyamidc (Nylon 66)with the liquid crystalline polyesters were incompatible, but a rather strong interaction between the polymers did exist.展开更多
文摘The employment of sustainable chemicals, such as citric acid, represents a possibility for the development of textile dyeing processes. This study aimed to analyze the possibility of replacement of acetic acid (commonly used in textile processing) by citric acid in polyester and polyamide 6 dyeing processes. The utilization of citric acid as leveling agent for disperse dyestuffs was also investigated. Dyeing processes in turquoise color for these fabrics were performed employing citric and acetic acid. Color differences between dyeing processes and color fastness to water were evaluated. All the color dyeing differences were not significant and there was no transference in color fastness tests (grade 5). Otherwise, the differences among polyamide dyeing processes could be related to the efficiency of citric acid solution as sequestering agent. Notwithstanding citric acid to be more expensive than acetic acid and the need of previous dissolution by stirring, it could be advantageous for some formulations.
文摘Blends of polyamide (Nylon 66) with two different kinds of liquid crystalline polyesters were studied in all the composition range. Homogeneous samples were obtained by coprccipitation from 2 wt%. solution of blends. The thermal properties, crystallinity and morphology of these blends were studied by using DSC, polarizing microscopy, and scanning electron microscopy. The phase transition and morphology of the blends are markedly-influenced by the composition of liquid crystalline polyesters. The mechanical behaviour of PHB/HNA-Nylon 66 blend was improved. although polyamidc (Nylon 66)with the liquid crystalline polyesters were incompatible, but a rather strong interaction between the polymers did exist.
