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Poly(ester amide)s (PEAs) composed of variable diols, dicarboxylic acids, and α-amino acids were synthesized and characterized to elucidate structure–property relationships. The PEAs were synthesized using both solution and interfacial approaches to obtain varying molecular weights (MWs) and polydispersities. Studies using differential scanning calorimetry and powder X-ray diffraction revealed a range of amorphous and semicrystalline behavior that was dependent on structure. The viscosities of the PEAs as a function of temperature were studied by rheology, and phase transitions were confirmed for some polymers. Mechanical properties were also investigated, and it was found that the PEAs could be tuned to exhibit elastomeric or brittle behavior by varying both the length of the diol and the amino acid moiety. This information provides new insights into the effects of PEA structure, MW, and MW distribution on PEA properties and will aid in the design and selection of PEAs with optimal properties for targeted applications.

SynopsisLiquid immersion development (LID) of a latent electrostatic image has become established as an important alternative to dry toning during the past decade. In this development method, a charged, colloidally stable colored particle that is dispersed in a dielectric fluid undergoes electrophoresis under the influence of a n applied field. These particles then neutralize a latent electrostatic image of opposite polarity, which resides on either a .photoreceptor drum or on dielectric paper. This results in a hard copy of the latent image being obtained. In this paper we outline the physicochemical properties that are demanded of a liquid toner and describe an alternative approach to the preparation of a LID materials package. This new approach utilizes a nonaqueous polymer colloid as the vehicle, which when colored and charged, gives a LID toner. The advantage of nonaqueous dispersions is that the steric stabilizer is irreversibly attached to the particle. Since desorption of the stabilizer is not a problem, these materials are colloidally stable for a n indefinite period of time. The particles were colored using both dyes and pigments. While neither approach was entirely satisfactory, the feasibility of coloring such particles was demonstrated. A positive charge was imparted to the particles by specific adsorption of the cation of a metal soap a t the polymer-fluid interface. It was found that these experimental LID toners were able to develop a latent electrostatic image in a commercially available printer with the image being well fixed to the paper. While this approach has not been optimized, it appears to be an attractive route for preparing novel LID developers.

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