Abstract:

Objective In order to further understand the dyeing performance of biodegradable polylactide/poly (3-hydroxybutyrate-co-valerate) (PLA/PHBV) blended fibers and their chenille yarns, and to improve the controlled dyeing technology of chenille yarn containing biodegradable polyester fiber, dyeing research was carried out.
Method The dyeing properties of PLA/PHBV fiber and PET/(PLA/PHBV) chenille yarn was studied and the parameters of dyeing rate constant, half dyeing time and diffusion coefficient were analyzed. Dyeing kinetics of C. I. Dispersed Red 60 on chenille yarn and its raw materials were explored and the biodegradable properties of each fiber were also studied.
Results The research results show that dyeing rate of C. I. Dispersed Red 60 on PLA/PHBV fiber and PET/(PLA/PHBV) chenille yarn was increased obviously with the increase of temperature, but the dyeing temperature was found not to exceed 110 ℃ in order to achieve the required mechanical properties of the fiber (Tab. 1 and Fig. 2). When the bath ratio was close to infinity, C. I. Dispersed Red 60 could stain the three materials faster at the initial stage of dyeing, after dyeing at 100 ℃ for 50 min, the adsorption capacity of the fibers to dyes basically reached the equilibrium state (Fig. 4(a)). When the dyeing temperature was increased to 110 ℃, the initial dyeing rate and equilibrium dyeing amount of C. I. Dispersed Red 60 on the three materials were significantly increased, and the time to reach the equilibrium state was shortened to about 40 min (Fig. 4(b)). The adsorption of C. I. Dispersed Red 60 on PET, PLA/PHBV and chenille yarn conformed to the quasi-second-order kinetic equation (Fig. 6). Among them, C. I. Dispersed Red 60 had the highest dyeing equilibrium adsorption capacity on PLA/PHBV fiber, and the lowest on PET fiber. With the increase of dyeing temperature, the dyeing rate of C. I. Disperse Red 60 on the three materials was accelerated (Tab. 3), the half staining time was shortened and the diffusion coefficient was increased (Tab. 4). The results of soil burial test showed that the degradation efficiency of all fibers increased with the extension of soil burial time, and PLA/PHBV fiber had the best degradation performance, followed by PLA. Moreover, the existence of PLA or PLA/PHBV biodegradable polyester fibers could accelerate the degradation rate of PET fiber (Fig. 8 and Fig. 9).
Conclusion It can be concluded from the research that with the increase of dyeing temperature, the dyeing rate of C. I. Dispersed Red 60 on PLA/PHBV fiber and chenille yarn increased, but the dyeing temperature should not exceed 110 ℃, otherwise the strength loss of PLA/PHBV fiber and chenille yarn was serious. The adsorption of C. I. Disperse Red 60 on PET, PLA/PHBV fibers and chenille fibers was consistent with the quasi-second-order dyeing kinetics model. By increasing the dyeing temperature to 110 ℃, the equilibrium dyeing amount, diffusion rate and diffusion coefficient of C. I. Dispersed Red 60 on PET, PLA/PHBV fiber and chenille yarn can be significantly improved, and the half-dyeing time can be shortened. C. I. Dispersed Red 60 had the highest equilibrium dye amount, diffusion rate and diffusion coefficient on PLA/PHBV fiber, and the shortest half-dyeing time. The corresponding value was the lowest in PET fiber. The blending of PLA/PHBV fiber is beneficial to improve the balance dyeing amount, diffusion rate and diffusion coefficient of chenille yarn, and shorten the half-dyeing time. The existence of PLA or PLA/PHBV biodegradable polyester fiber is beneficial to accelerate the degradation rate of refractory PET fiber, which provides a useful reference for the development of products containing biodegradable fiber. Biodegradable polyester materials have the dual advantages of protecting fossil resources and reducing carbon dioxide emission. The research, development and application of biodegradable polyester materials in textile field is an important innovative direction of sustainable development.

Key words: polylactide/poly(3-hydroxybutyrate-co-valerate) fiber, chenille yarn, disperse dye, dyeing property, dyeing kinetics