Study of the ditallowdimethylammonium chloride interaction with cellulose

Abstract

From a theoretical standpoint, the driving force for the deposition of ditallowdimethylammonium chloride ("DTDMAC" or "quat') onto cotton must be distinguished from the nature of its interaction with cellulose. We found that the driving force is purely hydrophobic. Due to its strong hydrophobicity, DTDMAC is expelled out of the aqueous rinse bath and deposits onto available surfaces. Besides its tendency not to leave the cotton surface and return to solution (hydrophobic effect), it binds to cellulose by weak London dispersion forces. A strong Coulombic interaction occurs only when a negative charge is present. Consequently, the strong affinity of DTDMAC for cellulose mainly results from the large specific surface area of the fiber; negative charges play a secondary role. Much experimental evidence supports the hydrophobic nature of DTD-MAC adsorption onto cellulose. DTDMAC deposits onto charge-free surfaces; its deposition is mainly governed by the available surface area, not by the surface nature. The hydrophobic nature of the interaction of DTDMAC with cotton may be displayed and distinguished from electrostatic binding. Structural effects demonstrate the correlation between hydrophobicity, deposition and the softening power of quaternaries. This model proposes a single mechanism to account for the deposition of DTDMAC onto cotton and synthetics. It is consistent with experimental facts that remain unexplained by the electrostatic model. 72, 137-143 (1995). JAOCS

Elucidation of Softening Mechanism in Rinse Cycle Fabric Softeners. Part 1: Effect of Hydrogen Bonding

“…Cotton surfaces are negatively charged because cotton consists of cellulose that contains anionic carboxyl groups that are generated by oxidation of OH groups. On the other hand, Crutzen [11] suggests that hydrophobic interactions derived from the long alkyl chains of cationic surfactants are the primary driving force for adsorption, because the softening agent can adsorb onto fiber surfaces that are not charged. Minegishi and Arai [12] report that the time required for the softening agent to reach adsorption equilibrium is strongly dependent on mechanical force.…”

“…It is suggested that a fiber-softening agent must decrease the frictional force between fibers and human skin. However, in another report, Crutzen [11] suggests that the effective softening agent does not necessarily reduce the frictional force.…”

Rinse‐added fabric softener technology at the close of the twentieth century

“…Over the last 40 yr, numerous investigations have been carried out on the kinetics and mechanism of cationic fabric softener deposition (2,(23)(24)(25). Kunieda and Shinoda (26) and Laughlin et al (27)(28)(29) investigated the basic phase behavior of dioctadecyldimethyl ammonium chloride as a model for the commercially ubiquitous product derived from tallow and have come to sometimes contradictory conclusions.…”

Elucidation of Softening Mechanism in Rinse‐Cycle Fabric Softeners. Part 2: Uneven Adsorption—The Key Phenomenon to the Effect of Fabric Softeners

“…However, there is uncertainty associated with this mechanism, because the sequence of adsorption is thermodynamically unfavorable: adsorption is followed by the formation of multilayers between the fibers and water by the cationic surfactants, which are sparingly soluble in water, together with subsequent formation of a monolayer between the fibers and air. Crutzen [5] suggested that hydrophobic interactions derived from the long alkyl chains of cationic surfactants are an important driving force in adsorption, because the softener can be adsorbed even on uncharged fiber surfaces. Minegishi [6] reported that the time required to attain adsorption equilibrium is strongly influenced by a mechanical force when the softener is adsorbed on cotton fibers.…”