Effect of nanoscale diamondoids on the thermomechanical and morphological behaviors of polypropylene and polycarbonate

Abstract

Nanoscale MolecularDiamond products (various diamondoid materials), obtained from petrochemical feedstocks, have been investigated as additives for polypropylene and polycarbonate. Three of the homologues of this family (diamantane, triamantane, and the [121]tetramantane isomer) have marginal effects on the thermal and mechanical properties of nonpolar/semicrystalline polypropylene. Mixtures of methylated tetramantane nanofillers also increase the stress-strain behavior of polypropylene composites without significantly impacting their glass transition temperatures. The addition of the selected diamondoids to amorphous/moderately polar polycarbonate increases the polymer tensile modulus significantly with marginal increases in the yield stress. The effects of the selected diamondoids on the thermal stability, crystallinity, and optical properties of polypropylene and polycarbonate are also reported. The results for the mechanical properties show that the selected diamondoids behave as plasticizers in polypropylene, whereas in polycarbonate, they act as antiplasticizers without adversely affecting the optical clarity.

Diamonds are a Chemist's Best Friend: Diamondoid Chemistry Beyond Adamantane

“…Ghosh et al could show that diamondoids are "... capable of modifying some thermomechanical properties of polymers without sacrificing other properties, as is often the case with larger filler inclusions." [169] In comparison to other polymer "additives" the role of diamondoids is not fully explored but the present results show that polymantanes (especially the functionalized ones) will probably give rise to materials with the above mentioned desirable properties.…”

“…[168] The [169] used diamondoids as additives for polypropylene and polycarbonate, and Chevron [35] tried using them as nucleating agents for the manufacturing of thermoplastics. Ghosh et al could show that diamondoids are "... capable of modifying some thermomechanical properties of polymers without sacrificing other properties, as is often the case with larger filler inclusions."…”

A comparative experimental and molecular simulation study on the mechanical and morphological behaviors of adamantane-based polypropylene composites

“…This has introduced a new way to obtain high performance PP as an engineering plastic. However, the physical properties of PP/diamondoids nanocomposites such as crystallization, mechanical and morphological behavior have been rarely studied [3]. Since it is difficult to control and measure all of these properties experimentally, computational modeling is considered as an alternative technique to provide some crucial insights.…”

“…ADM (C 10 H 16 ) is the smallest member of this group and since its first convenient synthesis by Schleyer [2] in 1957, extensive studies have been devoted to the use of ADMs as nanofillers [3][4][5]. It is due to the fact that ADM groups improve the properties such as stiffness, glass transition temperature and solubility of the composite [6][7][8].…”

Derivatization of diamondoids for functional applications

“…Because of such a unique molecular structure, diamondoids possess high thermal stability (melting point 269 1C, the highest melting hydrocarbons known), 3 superior chemical resistance, wide optical transparency, marvelous lubricating performance, and outstanding mechanical and electrical properties. 8,9 As the smallest member of the diamondoid series, adamantane (C 10 H 16 ) consists of a single cage-shaped diamond crystal subunit and dangling carbon bonds that are terminated with hydrogen. [4][5][6][7] The general chemical formula of diamondoid hydrocarbons is C 4n+6 H 4n+12 (where n is the number of diamond cage subunit), which are composed of all trans-fused cyclohexane rings in ''chair'' conformation.…”