The relationship between surfactant structure and soft property
Among the surfactant softeners, cationic surfactants have a strong adsorption effect on the surface of the fiber, and its directional alignment is relatively tight, which leads to the best effect.
The influence which Hydrophobic - based carbon chain makes to soft effects,can be thought of: C - C key can circle within a single bond and make the long chain into a curl of an irregular arrangement while keeping the bond Angle 109 DHS 28 cases. The molecular long chain has softness. Thanks to the softness, extension and contraction performance was attached to it when it is under the action of external force. In this way, the molecular of the softener plays a lubricating role on the surface of the fiber, reducing the dynamic and static friction coefficient between the fibers and the fibers, increasing the smoothness and softness of the fabric.
The effect of hydrophobic structure
The hydrophobic group is a surfactant with a linear or near linear chain of long chain aliphatic hydrocarbons. It has good effect on softness, and the softness of branched chain surfactant is not good.
Among monoalkyl, bialkyl and trialkyl long chain surfactants, the bialkyl cationic surfactant has a better effect ( withpoor biodegradability).
When the length of the alkyl chain increases, the soft effect is better. But with the increasing of the carbon chain, the water repellency enhances and the water absorption is worse. The C16 - C18 is the best.
An increase in the non-saturation of the alkyl chain can result in poor flexibility.
It can increase the surfactant water absorption Introducing weak hydrophilic groups or increasing number of hydrophilic groups into long chain hydrophobic group The introduction or addition of hydrophilic groups must be concentrated in the vicinity of the main hydrophilic groups to maintain the overall structure of hydrophilic and hydrophobic parts. If dispersed in the hydrophobic group chain, the softness can be significantly reduced.