Samuel Smith

The Preparation and Chemistry of Dicationically Active Polymers of Tetrahydrofuran

Abstract The anhydrides of the very strong acids, CF 3 SO 3 H and FSO 3 H, polymerize tetrahydrofuran (THF) to give a living polyether having cationic activity at each chain end. The surprising fact that both chain ends are cationically active necessitates the postulation of a reaction mechanism wherein the YSO,-ester end group (Y=CF 3 or F) formed as an intermediate in the polymerization generates an oxonium ion by a subsequent O-alkylation reaction involving either a THF molecule or a nearest neighbor ether group of the polymer chain. Kinetic studies of polymerizations involving (CF, SO,) 2 0 and the bis-ester, CF 3 SO 3 —C 4 H 5 —O 3 SCF 3 , as initiators indicate that chain growth is much faster where an oxonium ion rather than an ester is the end group. The chemistry of poly-THF dications is discussed. These are strong alkylating agents which make possible the facile preparation of unusual copolymers, block copolymers, and functionally terminated polymers.

Textile Characteristics Affecting the Release of Soil during Laundering1 Part II: Fluorochemical Soil-Release Textile Finishes

The behavior of fluorochemical surface finishing agents is examined with reference to several of the parameters which govern the ease with which soil is removed from textiles by laundering. Special attention is given to the composition and properties of a class of hybrid fluorochemical finishes which contain, in addition to perfluoroaliphatic groups that provide stain repellency in air, hydrophilic groups that enable the final polymer to show a reversal of surface character during laundering and thus provide improved soil release performance, particularly with respect to durable-press fabrics. The present work also includes a brief investigation of the normal stain release response of unfinished cotton, resin-stabilized cotton in the presence and absence of conventional hand-modifying, film-forming finishes, and unfinished polyester fabrics.

Textile Characteristics Affecting the Release of Soil during Laundering1 Part I: A Review and Theoretical Consideration of the Effects of Fiber Surface Energy and Fabric Construction on Soil Release

The efficiency of a given laundering process in effecting soil release from textiles is a complex function of the nature of the soil, the manner in which the soil was originally distributed in the fabric, the surface energy of the textile fibers, the fiber surface topography, and the overall fabric construction. The effects of these variables on the response of soiled textiles to laundering are reviewed and a theory is proposed to relate the known interactions with surface properties.