Other Coupling Agents

Dover Chemical Corporation produces resinous chlorinated paraffins under a name Chlorez . All Chlorez grades have a physical form of white powder (particles smaller than 50 mesh) with chlorine content around 70%. The manufacturer recommends Chlorez as flame retardants (in a combination with antimony trioxide) and lately as a nonreactive coupling agent under a brand name Doverbond (such as Doverbond DB 4300 or Doverbond 3000). The manufacturer claims that Chlorez in the amount of 10% along with 3% of a lubricant in the WPC shows an effect of a coupling agent and increases the flexural strength and modulus of the product, as well as the UV and moisture resistance (private communication, Dover Chemical Corp.). DB 4300 lists at 1.50/lb [12,13]. 

Clariant produces plastic compatibilizers of Cesa-mix series, including Cesa-mix 8611 (for use in polyethylene and polypropylene) and Cesa-mix 8468 (for polypropylene-based WPC). However, they are not in active usage in the WPC as yet. 

There are many coupling agents, compatibilizers, crosslinking agents and other dispersants described in the literature as experimental ones. They are not used industrially because of a number of reasons, mainly because of the lack of scale-up testing and the lack of hnancial considerations. Among them are, for example, iV-vinylformamide-grafted polypropylene [14] and poly(A-acryloyl dopamine [15]. 

EFFECT OF COUPLING AGENTS ON MECHANICAL PROPERTIES OF WOOD-PLASTIC COMPOSITES EXPERIMENTAL DATA 

TABLE 5.7 Effect of coupling agents on flexural and tensile modulus of WPC 

---

Other coupling agents include the tri- and tetrachloromethylbenzenes and divinylbenzene. 

Mittal, K.L., Silanes and Other Coupling Agents, VSP, Utrecht, 1992. 

The considerations raised in the introduction suggest a variety of mechanistic possibilities whereby sUane and other coupling agents might operate. These... 

For a review of peptide synthesis with dicyclohexylcarbodiimide and other coupling agents, see Klausner, Y.S. Bodansky, M. Synthesis, 1972, 453. 

Silanes and Other Coupling Agents. Edit. K.I. Mittal. The Fourth International Symposium on Silanes and Other Coupling Agents, MST Conferences, LLC in Orlando, FL, Vol.3. June 11-13,2003. 

---