High heat-resistant and high-strength polylactic acid fiber and preparation method thereof

Abstract

The invention discloses a preparation method for a high heat-resistant and high-strength polylactic acid fiber. The preparation method comprises the following steps: introducing an organic small molecule nucleating agent to polylactic acid through melt mixing; then self-assembling molecules of the organic small molecule nucleating agent having the content of 0.05 to 0.5wt% to form slender and efficient nucleating microfiber highly oriented along a fiber drawing direction under the actions of a melt spinning temperature field and a shear force field, wherein the microfiber induces the polylactic acid to be crystallized to form a highly oriented crystal structure while the crystallization of the polylactic aid is remarkably accelerated, so that the finally obtained high-performance polylactic acid fiber has the crystallinity degree of 42 to 59%, the tensile strength of 400 to 690 MPa and the boiling water shrinkage of 0.65 to 4.63%. The preparation method disclosed by the invention is not only smart in concept, and simple and efficient in process, easily realizes industrial scale production and opens up a simple and effective approach for development of the high heat-resistant and high-strength polylactic acid fiber.

Description

technical field [0001] The invention belongs to the technical field of polylactic acid fiber and its preparation, and in particular relates to a polylactic acid fiber with high heat resistance and high strength and a preparation method thereof. Background technique [0002] Synthetic polymer materials are widely used in various fields of the current national economy due to their outstanding advantages such as light weight and good flexibility. However, while traditional polymer materials bring great convenience to human production and life, because their synthetic raw materials mainly come from limited petrochemical resources, and their wastes are difficult to degrade quickly in the natural environment, with the development of petrochemical With the dwindling of resources and the deteriorating white pollution problems caused by waste plastics, the development of renewable resources as raw materials and biodegradable polymer materials to replace traditional petroleum-based, n...

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Problems solved by technology

However, due to the very slow crystallization rate of PLA, it is difficult to complete the crystallization in the melt spinning process, so that the heat resistance of the obtained fiber is limited by its low glass transition temperature (55-60 °C), and the heat resistance temperature is usually only 50 °C. -55°C, the resulting fabric cannot meet the high-temperature ironing and washing requirements of ordinary textiles (AATCCRev., 2003, 3:56-61); at the same time, PLA fibers with low crystallinity are easily hydrolytically degraded under higher temperature conditions , cannot be stained by conventional staining methods (ACSSustainableChem.Eng., 2015, 3:1039-1046)

In addition, although compared with traditional polymer fibers such as nylon (PA) and polyethylene terephthalate (PET), PLA fibers have more excellent hand feel, resilience, curl retention, flame retardancy, and Ultraviolet and other properties, but its mechanical strength is relatively not high enough (Ji Ping, Xu Yinbao, Jiang Zhirong, Properties and Applications of Polylactic Acid Fiber, Technological Innovation, 2003, 7:17-22)

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