What are the main components of acrylic yarn?

Acrylic yarn is mainly composed of polyacrylonitrile, which is copolymerized with over 85% acrylonitrile and no more than 15% of the second and third monomers. It is spun into staple fibers or filaments by wet or dry spinning.

The content of acrylonitrile accounts for more than 85%, which is called a monomer. Pure polyacrylonitrile has a compact structure, brittle and hard properties, and poor dyeing performance. The second monomer is usually used with compounds containing ester groups, such as methyl acrylate, methyl methacrylate, vinyl acetate, etc. After the addition of the second monomer, the regularity of the macromolecular arrangement becomes worse, and the intermolecular force decreases, resulting in a tendency to loosen the microstructure of the fiber, improving the flexibility of the fiber, improving the elasticity and handle, and facilitating the introduction of dye molecules to improve the dyeing performance of the fiber.

The content of the second monomer accounts for about 5% - 9%, and its amount not only affects the dyeing property of the fiber, but also has a significant impact on other properties. When other conditions remain unchanged, with the increase in the content of the second monomer, due to the decrease in the glass transition temperature of methyl acrylate, the stability of the heat resistant discoloration of the fiber decreases, that is, the fiber is prone to yellowing after heating, and the thermal creep variable of the fiber increases, the thermal shrinkage deformability increases, and the initial modulus decreases. The fiber is prone to deformation after heating, but due to the increased flexibility of the macromolecular chain segments, the finished fiber exhibits a good elastic recovery ability. The purpose of adding a third monomer is to introduce a certain amount of hydrophilic strong groups into the fiber to improve dyeing performance. The third monomer content is very low, generally around 1%.