High Compatibility of the Poly(oxypropylene)amine-Intercalated Montmorillonite for Epoxy

Abstract

ABSTRACT:The poly(oxypropylene)amine (POP-amine) intercalated montmorillonite (MMT) was found to have a high organophilicity and compatibility with epoxy materials. The 2000 g mol −1 molecular weight POP-amine modified MMT, analyzed to have 63 w% organics and 58.0 Å X-ray diffraction (XRD) d-spacing, was compounded with a curing agent (Jeffamine R D2000) and an epoxy resin (diglycidyl ether of bisphenol A). With 1-10 w% organoclay additions, the cured epoxies exhibited an exfoliated characteristic and significant improvements in thermal stability, solvent resistance and mechanical properties. The tensile strength (2.8 vs. 0.3 Mpa), flexural modulus (9.6 vs. 3.1 Mpa), and elongation (81.2 vs. 25.3%) were observed for the improved epoxy polymer.KEY WORDS Nanocomposites / Organophilic / Poly(oxypropylene)amine / Clay / Epoxy / In recent years, organic/inorganic nanocomposites have attracted a great deal of interests due to their proven industrial applications. 1-3 Most potential composite systems are hybrids of organic polymers and inorganic mineral clays consisting of layered silicates. [4][5][6][7][8][9][10] Mainly due to the high aspect ratio and plate-like morphologies 11 of the silicates, the nanocomposites have exhibited unique properties including mechanical strength, 12-16 thermostability, 17, 18 chemical resistance, 19, 20 gas barrier properties, 21, 22 solvent resistance, 20 etc. However, the naturally abundant silicate clay is hydrophilic in nature and lacks the affinity for hydrophobic organic polymers. To improve its miscibility with polymers, the layered silicate must be modified to become organophilic by widening the interlayer space with surfactants. The modification generally involves swelling the layered silicate lattice and also exchanging the interlayer metal cations with organic surfactant salts. 23 The widened interlayer spacing can then be incorporated by polymers, in which the layered silicates are exfoliated and well-dispersed. In literature, this key intercalating process has been well studied by using alky ammonium salts or amino acids as the intercalating agents. 5,12,23 The enlargement of the basal spacing to a maximum of 28 Å has been achieved. Previously, we found that further widening up to 92 Å was possible by employing the poly(oxypropylene)-backboned diamines. 24 The modified clays become highly organophilic and dispersible in hydrophobic toluene. The observation impels us to investigate their compatibility with the polymer matrix. In this paper, the epoxy system of diglycidyl ether of bisphenol A and a polyetheramine is chosen to study its compatibility with organic polymers. By simple mixing in the curing process, the modified organoclay is introduced into the epoxy matrix and their improving mechanical, thermal, and solvent resistant properties are demonstrated.

First Isolation of Individual Silicate Platelets from Clay Exfoliation and Their Unique Self-Assembly into Fibrous Arrays

“…In the literature, 18,20 Na + -MMT is generally exfoliated in the polymer-surrounded matrix and hence only possibly observed in the shape of interlayer lines from the side view.…”

Inhibitive properties comparison of different polyetheramines in water-based drilling fluid

“…Suter et al (2011) found that a polyether diamine with polyoxypropylene chains as backbones, a backbone of three monomer units per charged amine group was the maximum backbone length contributing to the highest inhibition efficiency, which was consistent with our experimental results. The interaction between clay and PEAs is presented in Scheme 1, which was proposed by Lin et al (2003) to explain the interaction between the polymer and montmorillonite, however, also illustrated the clay swelling inhibitive mechanism of PEAs.…”

Effect of amine‐terminated butadiene‐acrylonitrile/clay combinations on the structure and properties of epoxy nanocomposites

“…An increasing number of studies indicate that the increased hydrophobicity of clay and thus its interaction with the matrix can be achieved by modification of the montmorillonite (MMT) using various aminated polymer‐based polycations9–15 including aminated liquid rubbers, especially polybutadiene16; aminated nitrile rubbers such as ATBN17, 18; and aminated polyoxypropylene (APOP) and polyoxyethylene . 19–22 Most previous studies were devoted to the effect of the polymer‐modification of MMT on its degree of dispersion (exfoliation); the successful application of APOP‐modified MMT in epoxies10, 23–26 indicates that polymer‐intercalated clay may represent an effective type of toughener. Lin and coworkers23 observed the self‐pinning formation of lamellar arrays and enhanced behavior in the case of low‐ T g network.…”