Ultrasonic Mixing Of Epoxy Curing Agents

A new technique for mixing solid curing agents into liquid epoxy resins using ultrasonic energy has been developed. This procedure allows standard curing agents such as 4,4'-diaminodiphenyl sulfone (4,4'-DDS) and its 3,3'-isomer, (3,3'-DDS) to be mixed without prior melting of the curing agent. It also allows curing agents with very high melt temperatures such as 4,4'-diaminobenzophenone (4,4'-DABP) (242 C) to be mixed without premature curing. Four aromatic diamines were ultrasonically blended into MY-720 epoxy resin. These were 4,4'-DDS; 3,3'-DDS; 4,4'-DABP and 3,3'-DABP. Unfilled moldings were cast and cured for each system and their physical and mechanical properties compared.

Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

This book covers all aspects of the different classes of nanomaterials – from synthesis to application. It investigates in detail the use and feasibility of developing nanocomposites with these nanomaterials as reinforcements. The book encompasses synthesis and properties of cellulose nanofibers, bacterial nanocellulose, carbon nanotubes / nanofibers, graphene, nanodiamonds, nanoclays, inorganic nanomaterials and their nanocomposites for high-end applications such as electronic devices, energy storage, structural and packaging. The book also provides insight into various modification techniques for improving the functionality of nanomaterials apart from their compatibility with the base matrix.