Titanate coupling agents structure

Table 5b Structures and Physical Properties of Titanate Coupling Agents...

The structure of a titanate coupling agent is expressed by the general formula RO—Ti (OXRY)3. These titanate coupling agents are useful for improving flexibility and processability [70]. Joseph and coworkers [71]... 

Titanate coupling agents have been found to offer corrosion resistance12 and to give improved age and water resistance in reinforced plastics.13 Their application in thermoplastics has been discussed in detail,1415 the requirements of a coupling agent have been established16,17 and the theory of their use has been described.18 A summary of the different types of structure, with examples, is available.17... 

Figure 5.1 Chemical structures of two commercial titanate coupling agents.

Two examples of titanate coupling agents are shown below. The first contains amine groups and would be suitable for use with epoxide adhesives. Zirconate coupling agents have very similar structures to the titanates. 

CaC03 treated with 1 wt % titanate coupling agent KR-TTS, which is isopropyl triisostearoyl titanate (Kenrich Petrochemicals) with chemical structure... 

Zirconates Zirconate coupling agents have very similar structure to the titanates. They also perform similar functions. Zirconium compounds exist in both water and organic solvent soluble forms. Like the titanates, zirconate coupling agents are useful in improving the dispersion characteristics of fillers in polymer systems. Examples of zirconate coupling... 

GUlgiln M.A., Popoola O.O., Kriven W.M. X-ray photoelectron spectroscopy studies of bond structure between polyvinyl alcohol and a titanate cross-coupling agent. J. Mater. Res. 1995 10 1565-1571... 

Typical generalized structures of titanate and zirconate coupling agents are shown in Fig. 1. One of the proposed mechanisms for the effectiveness of the titanates in some composite systems is shown in Fig. 2. The water of hydration at the inorganic filler or fiber surface is re-... 

Fig. 1. Typical generalized structures of titanate/zirconate coupling agents. (Courtesy Kenrich Petrochemicals, Inc.)...

The last two items of the earlier list involve the behaviour of primers, in part chemical, in part physical, as forms of adhesives sticking the bulk adhesive to the actual metal, wood or other adherend. When dissimilar materials are to be joined, an adhesive suitable for one may not be so for the other. In these circumstances a primer for one of the substrates is chosen to be both suitable for it and compatible with the adhesive. Phenol-formaldehyde condensation products are often thus used particularly when the adhesive itself contains such material dispersed in another polymer, e.g. Redux775 (Bonded Structures, Ltd) or various epoxy-phenolic or nitrile-phenolic adhesives. Most important members of the class of coupling agents are the reactive silanes (siloxanes) and titanates. These materials have achieved their main use in the treatment of glass fibres for the manufacture of glass reinforced plastics. 

---