Document Type

Open Access Thesis

Embargo Period

8-27-2015

Degree Program

Polymer Science & Engineering

Degree Type

Master of Science (M.S.)

Year Degree Awarded

2015

Month Degree Awarded

September

Advisor Name

Shaw

Advisor Middle Initial

Ling

Advisor Last Name

Hsu

Abstract

The temperature profile needed to complete the reaction between the sodium-diamine complex and the isocyanate terminated prepolymer has been established. The sodium diamine complex has the advantage of blocking the nearly instantaneous reaction between the diamine and isocyanate from taking place until it is released at elevated temperatures. Because of its low melting temperature (~40 °C) and its low molecular weight (low viscosity), this chain extension reaction is not dependent on the participation of the prepolymer. Instead, the rate of reaction is dependent on the dissolution of the 4,4’-methylenedianiline (MDA) complex into the system. The dissolution of the MDA complex has been demonstrated to be strongly dependent on particle size. Both the plasticizer Bis(2-ethylhexyl) adipate and the quaternary ammonium compound found in soy lecithin play crucial roles for this reaction. The quaternary ammonium compound is crucial in the dissolution of the complexes. Although the plasticizer has been shown to dissolve the complex to a small extent, the principal role of the plasticizer is to disperse the complexes and to prevent their agglomeration. Other additives such as Dimethyl Sulfoxide (DMSO) have demonstrated to be highly efficient in dissolving the complex. However its effectiveness limits the mixing window needed before reaction take place, resulting in a disadvantage.

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