title: Modification of montmorillonite with aminopropylisooctyl polyhedral oligomeric silsequioxane.
abstract: Sodium montmorillonite (Na-MMT) was modified with various amounts of aminopropylisooctyl polyhedral oligomeric silsequioxane (POSS) and a second surfactant (alkyl ammonium based) via ion-exchange reactions. Interlayer spacing, interlamellar structure, and thermal and surface properties of these organoclays were characterized by wide angle X-ray diffraction, thermogravimetric analysis, and contact angle measurement. The interlayer space of POSS-modified clay (POSS-MMT) was strongly dependent on the arrangement of POSS surfactant but less dependent on the POSS concentration. The sodium ions in Na-MMT were only partially exchanged by protonized POSS due to the steric hindrance effect. In addition, the dual-surfactant-modified clays exhibited increased exchange ratios by controlling the amount of the second surfactant, resulting in a good balance in hydrophobicity and polarity of the modified clays. The resultant organoclays were mixed with polypropylene (PP) via a melt-compounding method. It was found that the dual-surfactant-modified clays with low polarity and similar hydrophobicity to PP were well dispersed in the PP matrix.
authors.affiliation: Department of Materials, Loughborough University, Loughborough, Leicestershire LE11 3TU, UK.
authors.forename: Feng
authors.initials: F
authors.lastname: Zhao
authors.forename: Chaoying
authors.initials: C
authors.lastname: Wan
authors.forename: Xujin
authors.initials: X
authors.lastname: Bao
authors.forename: Bala
authors.initials: B
authors.lastname: Kandasubramanian