Coupling agents, zircoaluminates

Various inorganic esters have been claimed as coupling agents for reinforced plastics, including aminobenzyl phosphonates, dicetylisopropylborate, alkoxy compounds of aluminum, zirconium and titanium, zircoaluminates, and numerous substituted titanates [1]. These metal alkoxides could function in a similar manner to the orthosilicates by reacting with hydroxylated substrates. Like the simple orthosilicates such as tetraethyl orthosilicate (TEOS), it is less evident how an-... 

Hunt et al. [ 17] have investigated the role of various coupling agents, such as zirconates, titanates, and zircoaluminates, in zirconia-polypropylene suspensions for use in the production of ceramics by injection moulding. All the coupling agents were observed to reduce the melt viscosity. 

The filler surface treatment can also be applied as an additive to the adhesive formulation. Coupling agents, such as organotitanates, zircoaluminates, or organosilanes, are added to the formulation so that they preferentially find their way to the filler s surface and provide for optimal surface chemistry and adhesion between the filler and the matrix resin. These coupling agents are discussed in Chap. 10. 

Zircoaluminates or aluminum zirconium me-tallo-organic complexes have proven useful as coupling agents and adhesion promoters. 

Zircoaluminate coupling agents are analogous to the silanes. Each of their product line has organic functionality and an inorganic backbone, so that one end can interact with the matrix resin and the inorganic component will have an affinity for the filler or reinforcement surface. 

Fig. 5. Representative structure of zircoaluminate coupling agents. RX is an organofiinctional group.

Cohen, L. B., Mineral Filled Resins In Situ Surface Modification With Zircoaluminate Metallo Organic Coupling Agents, SPE ANTEC, Paper 636, New Orleans, Apr. 1984. 

Cohen, L. B., Zircoaluminates Strengthen Premium Range Of Chemical Coupling Agents, Plastics Eng., 39(11), pp. 29-32 (1983). 

Cohen, L. B., The Chemistry and Reactivity of Zircoaluminate Coupling Agents for Filled and Reinforced Plastics, Society of the Plastics Industry, 41st RP/C Conference, Jan. 1986. 

Other Coupling Agents - The zirconates, zircoaluminates, and carboxylated polypropylenes are among the other coupling agents used with minerals for specific applications. 

---