Difunctional terminating agent

Similar products form from isocyanate-terminated polyethers. These materials can be crosslinked with difunctional quatemizing agents, such as l,4-bis(chloromethyl)benzene ... 

A further approach based on anionic polymerization methods is the use of a difunctional coupling agent to react across terminal sites. This method has been used in particular to generate an A—B—A triblock from an A—B diblock ... 

Effects of Curing Agent Type. Epoxide-Cured Propellant. Carboxyl-terminated polybutadiene is a linear, difunctional molecule that requires the use of a polyfunctional crosslinker to achieve a gel. The crosslinkers used in most epoxide-cured propellants are summarized in Table IV and consist of Epon X-801, ERLA-0510, or Epotuf. DER-332, a high-purity diepoxide that exhibits a minimum of side reactions in the presence of the ammonium perchlorate oxidizer, can be used to provide chain extension for further modification of the mechanical properties. A typical study to adjust and optimize the crosslinker level and compensate for side reactions and achieve the best balance of uniaxial tensile properties for a CTPB propellant is shown in Table V. These results are characteristic of epoxide-cured propellants at this solids level and show the effects of curing agent type and plasticizer level on the mechanical properties of propellants. 

The fact that the polymers have terminal anions, enables these molecules to be linked together at their ends. If the linking agent is difunctional, such as in the case of an alkyl dihalide, it is referred to as a coupling agent and the... 

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