subject: To Improve The Dyeing Properties Of Polyester Blends Of Polypropylene Fiber Additive - Dyeing, Fiber [print this page] PP fiber is one of the main synthetic varieties, rich in raw materials, low price, light weight, high thermal stability, hydrophobicity, and good thermal and corrosion resistance, anti-mildew, has good processing properties and mechanical properties . But the high crystallinity and no dye molecules compared with the role of polar groups, leading to difficulties in its staining [one]. Purports to have the dyeability of polypropylene fiber is required on the modified polypropylene [2,3], one of its methods of mixing can be dyed Additive .
Modified polypropylene blend additives used generally polar materials such as polyester, polyamides, polyolefins, reactive resin-like polymer additives and so on, and at least four conditions must meet the following :
? Modifier and polypropylene has good compatibility, can be formed in the molding process matrix? Micro-fiber two-phase structure, and generate a large number of micro-pores, the formation of dye spread to the internal fiber channel, which Implementation staining
? Modifier has a good affinity with the dye, made from the fiber to ensure sufficient depth and color fastness of dyeing;
? Modifying agent should have good thermal and chemical stability, non-toxic;
? PP modifier should not be spinning, mechanical properties, thermal properties and optical properties have a negative impact.
Polyethylene terephthalate (PET) and its modification is most commonly used additives of polypropylene fibers can be dyed. Use polyester modified polypropylene has two advantages: on the one hand, simple, chromatography wide, bright color; the other hand, with a dye additives in the polypropylene seat evenly distributed, so the law can only polypropylene fiber surface staining, but also to make polypropylene fiber body staining. Polyester blend additives not only the structure of porous polypropylene, but also in situ in the polypropylene fibers to form a matrix - micro-fiber two-phase structure, because there is a lot of interface between the two phases and the formation of large pores, there help spread the dye molecules along the porous fiber interior, which produce the so-called "wicking effect", and with Polyester and aromatic ester such as the active site affinity dye, in the weak hydrogen bonds, van der Waals force, ionic bond or polar covalent bond under the dye adsorption, so as to achieve the purpose of dyeing.
1 polyester blend additives dyeability of modified polypropylene dyeability with the relationship between
For polypropylene modification to improve its dyeing properties of additive itself must be dyed. Modified polypropylene may be dyed the same type of additives that can be infected if the additives are dispersed, then the modification can only disperse dyeable polypropylene; If the additive is a cationic dye, the cationic dyeable polypropylene can ; If the additive is a high temperature and pressure can be dyed, the modified polypropylene is also required under the conditions of high temperature and pressure dyeing.
2 polyester blend additives dyeability Earlier for modified polypropylene polyester is PET. However, only PET modified polypropylene, high temperature and pressure conditions, only with disperse dyes. Anionic-dyeable polyester containing additives is through the introduction of basic groups of the copolymer composition, it has affinity for acid dyes, usually the third component is the introduction of amine (tertiary amine, quaternary ammonium) compounds. However, the third monomer containing nitrogen poor thermal stability, resulting in poor staining fibers are heat-resistant, color fastness low. Therefore, limiting the development of such additives.
Cationic dye chromatography as complete, colorful and inexpensive, so the main chain in the polyester monomer into the third?? Dimethyl isophthalate sodium (SIPM), which are combined with cationic dyes get a solid color polyester blend additives is one of the most popular. In addition to the introduction of additives containing SIPM a dye blocks, the structure has been damaged during bit of polyester macromolecules regular structure [4], to slow down the crystallization rate, crystallinity decreased, increasing the amorphous region is conducive to dye molecules Since the amorphous polyester interior area to the infiltration, and with-SO3-binding. Although the additives on the dyeing rate
SIPM content with the increase of SIPM to join, but if excessive, the spinnability of additives, and other physical properties deteriorate. SIPM molar content of 1.5% (relative to the terephthalic acid content, the same below) below, less fiber dyeing, dye left in the residue of the majority; SIPM molar content of 1.5% above, the basic color to fiber requirements [5]. Therefore, the content of general SIPM 2% ~ 3 mol%.
3 block copolymer and the additive random copolyester
Block copolymer is a long chain embedded in polyester with pure PET segment and the fourth from the third monomer and monomer modified copolyester segment, due to its chain of the regularity and symmetry are the third four monomer damage, difficult to participate in the crystallization, the formation of crystalline chains. Random copolyester is the third single and fourth single randomly distributed across the polyester long chain. Compared with the random copolyester, block copolymer of SIPM heat setting in the fiber are more concentrated in the amorphous region, susceptible to dye cationic dye molecules. Therefore, the block copolymer is better than random dyeing of polyester. For example, the molar content of 2.5% SIPM the same block copolymer and random copolymer of the slice, parallel staining experiments show that the spinning [6], the former high rate of dyeing, dye saturation value of 3.52, the color depth; the latter 2.25, lighter in color, consistent with the prediction.
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