Diuron cure system

The Diuron cure system provides excellent scorch safety, good shelf life, but moderate cure rates. The use of up to 6 pphr will improve cure rates at some sacrifice in scorch safety. This product is not recommended with non-black fillers. The physical properties obtained with Diuron are excellent, except the elongation is lowered with higher loadings. The compression set is good and heat aging is excellent with Diuron compounds. Rhenocure Diuron is an 80% dispersion that is recommended in place of the pure Diuron. 

Chlorine/carboxyl cure-site ACM provides a wide variety of cure systems depending on the process and functional properties required. Table 5.14 gives a summary of the various systems used with the expected characteristics for each. Of these, there are four cure systems used in common practice, the Diuron, HyTemp SC-75, HyTemp NPC-25, and Butyl Tuads. A comparison of these cure systems is shown in Table 5.15. 

Two resin systems utilising accelerated DICY cure have been studied by Schneider et al. 61 . The systems were BADGE/Epoxy cresol novolak /p-t-butylphenylglycidyl ether/DICY/Monuron in the wt.-% proportion 30/57/1.5/8/3.5, Resin 1, and TGDDM/epoxy cresol novolak/BADGE/DICY/Diuron, 70/14/5/3.5/3, Resin 2. Typical DSC scans at 5 K/min heating rate for the two resins are shown in Figs. 13 and 14. 

Resin II contains tetraglycidyl methylene dianiline (TGMDA) as the principal epoxide with small amounts of a cresol novolac and DGEBA. DICY as curing agent is present in an amount such that the amine epoxy ratio is 0.25. Diuron is the accelerator. The supplier s recommended standard cure is the same as for SP250. However, in this system approximately 20 percent of the epoxide remains unreacted following the cure cycle (1 ). Selected resin plates were subjected to additional cure at 170°C and 220°C. The samples post cured at 220 C for forty minutes showed no residual epoxide absorbance in the IR spectrum. 

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