Imagine a soft cotton bath towel that won't dry, or a white shirt that yellows when ironed.
Silicone fabric softeners play an important role in the textiles we use daily. Pretreatment, dyeing and fixing processes make fabrics impossibly stiff and unappealing unless they are properly finished using corrective measures. Silicone softeners turn brittle fabrics into soft and pleasing textiles that we wear and use with comfort and ease.
But today's finishes took time to develop. Over the last century, chemists have tried a variety of silicone technologies to enhance fabrics. In the mid-20th century, a first generation of polysiloxane was widely adopted for its improved fabric softening effects. Enhancements in the 1980s launched next-generation polysiloxane technologies using amino-functional silicones.
The interactions of amino groups with textiles, in particular cotton, allowed these new polysiloxanes to physically adsorb onto fiber surfaces, further enhancing the softening effects. The textile industry was initially excited to adopt this new type of finish. Unfortunately, the final products were still hydrophobic, unable to absorb water, and their fabric colors discolored when heated or ironed.
Researchers have since dramatically improved silicone fabric treatment technologies. New-age polysiloxanes were advanced in the 2000s using polyetheramines to modify their silicone backbone. The resulting amine groups and short polyglycol chains not only increased water absorption and fabric softness, but also enhanced the softener’s emulsion stability. Emulsion stability is important feature for textile makers, because it alleviates softener emulsion separation issues so often associated with other types of polysiloxane used in the fabric finishing process.