Ethylene-Propylene-Diene compounds

EPM/EPDM compounding pLASTOTffiRS, SYNTTiETIC - ETHYLENE-PROPYLENE-DIENE RUBBER] (Vol 8)... 

Dithiophosphates. These compounds (13) are made by reaction of an alcohol with phosphoms pentasulfide, then neutralization of the dithiophosphoric acid with a metal oxide. Like xanthates, dithiophosphates contain no nitrogen and do not generate nitrosamines during vulcanization. Dithiophosphates find use as high temperature accelerators for the sulfur vulcanization of ethylene—propylene—diene (EPDM) terpolymers. 

FIGURE 12.7 Monsanto rheometric curves of ethylene-propylene-diene monomer (EPDM) rubber-melamine fiber composites [64]. A, gum compound B, compound containing 30 phr melamine fiber but no dry bonding system and C, compound containing both dry bonding system and 30 phr melamine fiber. (From Rajeev, R.S., Bhowmick, A.K., De, S.K., Kao, G.J.P., and Bandyopadhyay, S., Polym. Compos., 23, 574, 2002. With permission.)... 

The most prevalent approach to achieve long-lasting and nonstaining ozone protection of rubber compounds is to use an inherently ozone-resistant, saturated backbone polymer in blends with a diene rubber. The ozone-resistant polymer must be used in sufficient concentration (minimum 25 phr) and must also be sufficiently dispersed to form domains that effectively block the continuous propagation of an ozone-initiated crack through the diene rubber phase within the compound. Elastomers such as ethylene-propylene-diene terpolymers, halogenated butyl mbbers, or brominated isobutylene-co-para-methylstyrene elastomers have been proposed in combination with NR and/or butadiene rubber. 

FIGURE 30.11 Sampling along a compounding line for a filled ethylene-propylene-diene monomer (EPDM) compound curatives addition on open mill. 

FIGURE 30.12 Ethylene-propylene-diene monomer (EPDM) compounding complex modulus strain dependence samples TR, EM, and AG. 

Ethylene-Propylene-Diene Monomer (EPDM) Compounding RPA-FT Results at 100°C Complex Modulus Dependence on Strain Eit Parameters of Equation 30.3... 

FIGURE 30.17 Ethylene-propylene-diene monomer (EPDM) compounding corrected total torque harmonic content (TTHC) versus strain, at 1.0 Hz slope at 200%, as calculated with Hrst derivative of Equation 30.4 and fit parameters in Table 30.2. 

FIGURE 30.18 Ethylene-propylene-diene monomer (EPDM) compounding quarter cycle integration ratio versus strain, at 0.5 and 1.0 Hz samples at position TR (at dump), EM (after curatives addition), and AG (after cooling). 

Thioureas mainly find use for the vulcanisation of CR, epichlorohydrin (ECO) and some ethylene propylene diene terpolymer (EPDM) compounds. They show high crosslinking activity, with usually adequate compound flow time before onset of the crosslinking. In EPDMs, the thioureas are used as activators for low activity third monomer types and, in the presence of calcium oxide desiccants, in free state vulcanisation of extrudates, etc. The use of thioureas can overcome the retardation caused by the desiccant. In this case some care must be taken otherwise overcompensation may occur. Thioureas are not used in food product applications and are a known health hazard, particularly for pregnant women. 

EPM/EPDM compounding pLASTOMERS, SYNTHETIC - ETHYLENE-PROPYLENE-DIENE RUBBER] (Vol 8) -m fats and oils [CARBOXYLIC ACIDS - ECONOMIC ASPECTS] (Vol 5)... 

Post and co-workers [49] have used TG-FTIR to study the outgassing of a plasticiser (type and amount) from an ethylene-propylene-diene terpolymer (EPDM) compound. Figure 1.6 shows the thermogravimetric decomposition behaviour of the EPDM compound. The plasticiser emerges in the first mass-loss step, which was identified as adipic acid diisobutylester by on-line infrared analysis. 

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