Epoxidharze aus hydantoinen

Several N,N′-diglycidyl derivatives, N,O-diglycidyl compounds, diglycidyl ethers, diglycidyl esters, tri-and polyglycidylated products can be prepared from hydantoins. Syntheses and physical properties of these resins are compared, and for selected examples some properties after curing with usual hardeners are given.     

Monothiirane als reaktive Verdünner für Epoxidharze

Long-chain aliphatic monothiiranes can be used as reactive diluents for epoxy resins. The properties of the cured products are the same as those reached with adequate monooxiranes (monoglycidylethers or esters). The advantage of the use of monothiiranes is the acceleration of the curing with aliphatic polyamines and acid anhydrides, and their lower toxicity.     

Einfluß struktureller Merkmale auf die physikalischen Eigenschaften vernetzter Epoxidharze

With the epoxy polyaddition system some fundamental relations between chemical structure and physical properties of crosslinked materials are shown. It became evident, that the morphology of the polymers is characteristically influenced not only by the segments between the crosslinks but also by the crosslinking fragments formed during the polyaddition reaction. Amine cured epoxy-systems show distinct β-relaxations causing higher toughness and flexibility as well as higher glass transition temperatures than the anhydride cured polymers. Similar systems result by crosslinking epoxidised cycloolefines with aliphatic polycarboxylic acids. The importance of the structure of the segments in positions between the crosslinks is shown by specific resin/hardener compositions. The influence of the network structure on the physical properties of the cured specimen is demonstrated by the degree of curing, crosslinking density, structural symmetry of the agents used, the molecular orientation and cristallization.