EPOXY THERMOSET COMPOSITIONS COMPRISING EXCESS EPOXY RESIN AND PROCESS FOR THE PREPARATION THEREOF
In one aspect, embodiments disclosed herein relate to a process for curing a thermoset composition, including: reacting a curable composition comprising an epoxy resin, an epoxy-reactive compound, and a catalyst, wherein there is a stoichiometric excess of the epoxy resin; to form an intermediate product having unreacted epoxy groups and secondary hydroxyl groups; and etherifying at least a portion of the unreacted epoxy groups and the secondary hydroxyl groups, catalyzed by the catalyst, to form a thermoset composition.
1 . A process for curing a thermoset composition, comprising:
reacting a curable composition comprising an epoxy resin, an epoxy-reactive compound, and a catalyst, wherein there is a stoichiometric excess of the epoxy resin; to form an intermediate product having unreacted epoxy groups and secondary hydroxyl groups;
etherifying at least a portion of the unreacted epoxy groups and the secondary hydroxyl groups, catalyzed by the catalyst, to form a thermoset composition.
2 . The process of claim 1 , wherein the reacting comprises reacting the epoxy resin with the epoxy-reactive compound.
3 . The process of claim 1 , wherein the curable composition comprises from about 10 percent to about 1000 percent stoichiometric excess of the epoxy resin.
4 . The process of claim 1 , wherein the catalyst is an imidazole.
5 . A thermoset composition comprising the reaction product of a stoichiometric excess of an epoxy resin, an epoxy-reactive compound, and a catalyst, wherein the stoichiometric excess of epoxy resin has substantially reacted.
6 . The thermoset composition of claim 5 , wherein the thermoset composition has a glass transition temperature (T g ) as measured by DSC greater than that of a similar epoxy-resin based composition formed using a balanced stoichiometry.
7 . The thermoset composition of claim 5 , further comprising at least one of a filler, a nanofiller, a surfactant, a toughening agent, and a tackifying agent.
8 . The thermoset composition of claim 5 , wherein the thermoset composition has a fracture toughness of at least 1.2 MPa·m 1/2 .
9 . The thermoset composition of claim 5 , wherein the thermoset composition has a density of less than 1.18 g/cc.
10 . The thermoset composition of claim 5 , wherein the thermoset composition ahs a tensile modulus of at least 3000 MPa.
11 . A process for forming a composite, comprising:
disposing a curable composition on a substrate, wherein the curable composition comprises an epoxy resin, an epoxy-reactive compound, and a catalyst, wherein there is a stoichiometric excess of the epoxy resin; reacting the epoxy resin with the epoxy-reactive compound to form an intermediate product having unreacted epoxy groups and secondary hydroxyl groups;
etherifying at least a portion of the unreacted epoxy groups and the secondary hydroxyl groups, catalyzed by the catalyst, to form a thermoset composition.
12 . The process of claim 11 , wherein the curable composition comprises from about 10 percent to about 1000 percent stoichiometric excess of the epoxy resin.