Metilurea is an important pharma intermediate. With its simple molecular structure and unique chemical properties, it has been widely used in the fields of medicine, pesticides and fine chemicals. Besides being used as an intermediate in pharmaceutical of medicine and pesticide, the research and application of methylurea in the field of dyes are also of great value. Its chemical properties determine its potential in dye molecular modification, dye preparation process and functional dye development.
Applicability of Methylurea in Dye Field
The characteristics of methylurea make it have the following advantages in the field of dyes:
Molecular modification ability: by reacting with active groups in dye molecules, dye molecules are modified to give them new functions.
Mild reaction conditions: the reaction of methylurea does not need high temperature and high pressure, which is suitable for large-scale industrial production.
Environment-friendly: Compared with some highly toxic organic reagents, methylurea is less toxic and more in line with the principle of green chemistry.
Specific Application of Methylurea in the Field of Dyes
Preparation of amide dyes
Amide dyes are an important class of organic dyes, which are widely used in textile, leather and paper dyeing. Metilurea reacts with acidic or basic compounds to generate dye molecules containing amide groups:
Reaction process: the urea group of n methyl urea reacts with aromatic acid or acyl chloride to form amide bond, which makes the dye have good stability and color fastness.
Performance improvement: the introduction of n methyl urea can improve the solubility and dispersibility of dyes and improve their adhesion in fiber materials.
Modification of azo dyes
Azo dyes are famous for their bright colors and good light fastness. Metilurea has the following functions in the modification of azo dyes:
Enhance color stability: the carbonyl group of n methyl urea can form hydrogen bonds with the aromatic ring of azo dyes, which enhances the intermolecular force, thus improving the light resistance and thermal stability of dyes.
Introducing functional groups: By reacting with amino groups or hydroxyl groups in azo dyes, n methyl urea can introduce new functional groups, making the dyes have antibacterial, ultraviolet-proof or conductive properties.
Development of reactive dyes
Reactive dyes are dyes that combine with fiber materials through chemical reactions. Metilurea in reactive dyes can:
Enhance fiber adhesion: the urea group of methylurea can covalently bind with hydroxyl or amino groups on the fiber surface, thus enhancing the adhesion of dyes.
Reduce the processing temperature: By using reactive dyes modified by methyl urea, the dyeing process can be completed at a lower temperature, reducing energy consumption.
Modification of disperse dyes
Disperse dyes are mainly used for dyeing polyester fibers, and n methyl urea can improve the performance of disperse dyes in the following ways:
Improve dispersibility: The water solubility and hydrogen bonding ability of methylurea can help to reduce the aggregation of disperse dye particles and improve dyeing uniformity.
Improve washability: disperse dyes modified by n methyl urea are not easy to decolorize after high temperature dyeing, which is suitable for the application of high performance fiber materials.
Development of functional dyes
With the rise of functional textiles, methylurea has also played an important role in the development of functional dyes:
Antibacterial dyes: The complexes of methylurea with metal ions such as silver and copper can be used to prepare antibacterial dyes for medical textiles.
Conductive dyes: By combining with conductive compounds, methylurea can generate conductive dyes for smart textile materials.