Preparation of nylon 66/mesoporous molecular sieve composite under high pressure

Abstract

Nylon 66/mesoporous molecular sieve (pore diameter: 2.7 nm) composites were prepared by annealing mixtures of nylon 66 and mesoporous molecular sieve (FSM) powders under high pressures and high temperature (FSM content: 0 -60 wt %; pressure: 0.5-30 MPa; temperature: 300°C; time: 1 h). X-ray diffraction and TEM measurements indicated the presence of the pores of FSM in the composite. Above 2 MPa, nylon 66 was charged in the pores of FSM. The fraction of the charged nylon 66 increased with pressure and was independent of the FSM content (pressure: 2-30 MPa; fraction of charged nylon 66: 54 -66%). The infrared spectrum of the composite showed the bands based on SiOO, COH, NOH, CAO. DSC measurement indicated that the heat of fusion of nylon 66 crystallite in the FSM pores was low compared with that of nylon 66. The composites prepared above 2 MPa were found to be superior in storage modulus to nylon 66. The modulus increased with an increase in the fraction of charged nylon 66 and the amount of FSM.

Mesostructured silica for the reinforcement and toughening of rubbery and glassy epoxy polymers

“…tetraethylorthosilicate, TEOS) [9][10][11][12] or purely inorganic reagents (e.g., sodium silicate and colloidal silica) [12][13][14][15][16][17][18]. These mesostructured forms of silica show considerable promise as reinforcing agents for several engineering polymer systems at relatively low particle loadings due in part to the high surface area and favorable interfacial interactions between the polymer and the silica surface [19][20][21][22][23][24][25][26]. The unique pore structures provide enough intraparticle space for the polymer to impregnate the particles and form a unique composite structure.…”

Reinforcement of a Rubbery Epoxy Polymer by Mesostructured Silica and Organosilica with Wormhole Framework Structures

“…[16][17][18] A few attempts have been made to use ordered mesoporous forms of silica for polymer reinforcement. [18][19][20][21][22][23][24] For instance, two dimensional MCM-41 [19,20] silica (pore size $3 nm) and three dimensional MCM-48 silica [21,22] (pore size $3 nm) were found to function as reinforcing agents in the in-situ polymerization of polyimide, poly(3-trimethoxysilypropylmethacrylate), poly(vinyl acetate) and poly(methyl Mesostructured forms of silica (denoted MSU-J) and aminopropyl-functionalized silica (denoted AP-MSU-J) with wormhole framework structures are effective reinforcing agents for a rubbery epoxy polymer. At loadings of 2.0-10 wt %, MSU-J silica with an average framework pore size of 14 nm (65 8C assembly temperature) provides superior reinforcement properties in comparison to MSU-J silica with a smaller average framework pore size of 5.3 nm (25 8C assembly temperature), even though the surface area of the larger pore mesostructure (670 m 2 g À1 ) is substantially lower than the smaller pore mesostructure (964 m 2 g À1 ).…”

“…However, attempts to use MCM-41 and related mesoporous forms of silica as reinforcing agents by direct dispersion in a polymer matrix have been less successful. For instance, a Nylon 66 [23] composite containing 35 wt % of hexagonal FSM silica (average pore diameter <3.5 nm) exhibited only a 2-fold increase in storage modulus. Marginal improvements in the tensile properties also were observed for hexagonal MCM-41 silica filled polypropylene under supercritical CO 2 conditions.…”

Ordered Mesoporous Silica Derived from Layered Silicates

“…The morphological control of mesoporous silica such as FSM-16 and KSW-2 is quite difficult because the starting layered silicates cannot be morphologically controlled. On the other hand, there has been a report on the preparation of a Nylon66/FSM-16 composite as a polymer film, [189] which may be another possibility for the application of mesoporous silica derived from layered silicates.…”