No abstract

A new type of organic intercalation system using poly(muconic acid) and poly(sorbic acid) crystals as the host compounds is described. The layered polymer crystals as the host are derived from benzyl-, dodecyl-, or naphthylmethylammonium salts of (Z,Z)-muconic or (E,E)-sorbic acids by topochemical polymerization. The subsequent solid-state hydrolysis of the resulting ammonium polymer crystals provides the corresponding carboxylic acid polymer crystals. When alkylamines are reacted with poly(muconic acid) or poly(sorbic acid) crystals dispersed in methanol at room temperature for a few hours, the intercalation proceeds to give layered ammonium polymer crystals via solid-state reactions, in which the polymers maintain a layered structure throughout. The interplanar spacing value of the polymer crystals changes according to the size of the guest molecules; that is, it exactly depends on the carbon number of the alkylamines used for each reaction of poly(muconic acid) or poly(sorbic acid) crystals. The stacking structure of alkyl chains with a tilt in the intercalated alkylammonium layers exists irrespective of the chemical and crystal structures of the host polymers. The intercalation of higher alkylamines into poly(muconic acid) crystals proceeds fast and quantitatively, while the conversion is dependent on the reaction conditions such as the structure and amount of the amine and the reaction time during the intercalation with poly(sorbic acid) crystals, due to the difference in the repeating layered structures of these polymer crystals. Some functional amines are also used as the guest molecules for this organic intercalation system.

Abstract. Stability of nanostructures of epoxy/acrylic triblock copolymer blends was studied. PMMA-b-PnBA-b-PMMA triblock copolymers (acrylic BCPs) having several compositions on the ratio of the block chains and the molecular weight were initially prepared and were blended with diglycidyl ether of bisphenol-A epoxy thermosets. The blends were cured using phenol novolac with tri phenyl phosphine (TPP) as the catalyst. Several nanostructures, such as spheres, cylinders, curved lamellae, were observed in the cured blends. The nanostructures were controlled by the molecular weight of the immiscible PnBA-block chain and the ratio of the PnBA in the blends. Moreover, the effect of the gel time to the nanostructures was examined by altering the trace amount of the TPP in the blends. The types of the nanostructures were almost kept irrespective of the gel time of the blends when the composition of the blends was maintained. This suggested the stability of the nanostructures of the epoxy/acrylic BCP blends made via the self-assembly mechanism, therefore a phase diagram of the cured blends was proposed.

Four kinds of stereoregular poly(muconic acid)s, which are synthesized by topochemical polymerization and subsequent solid-state hydrolysis, are used as the organic host materials for intercalation. We describe the reaction behavior and layered structure of intercalation compounds using stereoregular poly(muconic acid)s and n-alkylamines as host and guest, respectively. The packing structure of the guest alkylamines was determined by X-ray diffractions as well as IR and Raman spectroscopies. We have found that the orientation of the guest molecules is controlled by the host polymer tacticity, depending on the structure of the two-dimensional hydrogen-bonding network formed in the polymer sheets of the crystals.

Epoxy thermosets are applied as structural materials and adhesives in many industries, such as aerospace, automotive, and electronics, due to their excellent mechanical properties and heat/solvent resistance. In the applications, polymer blends have been studied to toughen the epoxy thermosets [1-14]. Among various toughening modifiers, block copolymers (BCPs) consisting of chemically distinct block chains have attracted attention in order to give nanostructured epoxy blends [15-40]. After the finding of the nanostructured epoxy blends with amphiphilic BCPs [15, 16], many BCPs were synthesized to study the nanostructures and the mechanical properties of the cured blends. Dean et al. [21] reported that methylenedianiline-cured DGEBA/ poly(ethylene oxide)-b-poly(butadiene) (PEO-b-PB) block copolymer blends showed a phase transition from spherical micelles to branched cylindrical micelles and finally to vesicles, as the volume fraction of the epoxy-miscible PEO block decreased. Ritzenthaler and coworkers [23, 24] studied epoxy/ ABC triblock copolymer blends. Raspberry-like nanostructures were identified in polystyrene-bpolybutadiene-b-poly(methyl methacrylate