02307nas a2200205   4500008004100000022001400041245013300055210006900188260006800257300001400325490000800339520148100347653003401828653001901862653001501881653001701896100003101913700002501944856013201969       2010                        eng d  a0021-899500aInfluence of structure of organic modifiers and polyurethane on the clay dispersion in nanocomposites via in situ polymerization0 aInfluence of structure of organic modifiers and polyurethane on   a111 RIVER ST, HOBOKEN, NJ 07030 USAbJOHN WILEY & SONS INCcNOV  a1774-17860 v1183 a<p>Influence of polyurethane (PU) structure on the nature of PU/clay nanocomposite was studied using varying amounts of trimethylol propane (TMP) as branching agent. The effect of hydroxyl groups in the modifier of organoclays on the structure of PU/clay nanocomposites was studied. Nanocomposites were characterized using wide-angle X-ray diffraction measurements (WAXD) and transmission electron microscopy (TEM). The results show that formation of completely exfoliated and well dispersed polyurethane/clay nanocomposites via in situ polymerization, is facilitated by the presence of tethering groups on the clay surface and an ability to form branched and crosslinked structures. Incorporation of long alkyl chains in addition to tethering hydroxyl groups in the modifier structure of the clay did not significantly improve the compatibility of linear PU with the clay. Intercalated thermoplastic polyurethane/clay nanocomposites, prepared using poly(caprolactone diol) as soft segment and isophorone diisocyanate and 1,4-butanediol as hard segments show increase in storage tensile moduli at temperatures before glass transition temperature when functional groups capable of chemically reacting with the growing polymer chains are present in the clay modifier. This is indicative of improved interaction of the polymer with the clay surface when the modifier has larger number of hydroxyl groups. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 118: 1774-1786, 2010</p>10aintercalation and exfoliation10aNanocomposites10aorganoclay10apolyurethane1 aRama, Mallikarjuna, Shroff1 aSwaminathan, Sivaram  uhttps://library.ncl.res.in/content/influence-structure-organic-modifiers-and-polyurethane-clay-dispersion-nanocomposites-situ-0