Cure-rate index

Mechanical Properties and Cure Rate Index of the Mixes—Role of Dry Bonding System on the Reinforcement of Ethylene-Propylene-Diene Monomer (EPDM) Rubber with Melamine Fiber ... 

R Radical pkj, of Free Amine Mooney Scorch Cure Rate Index at135°C... 

Sample Maximum torque (Mh) (dNm) Delta torque (dNm) Cure time (tgo) (min) Cure rate index (CRI) (min- )... 

Rheological studies must be carried out to obtain information about the optimal time to vulcanization process, adjusting the vulcanization system to get the best mechanical properties or thermal properties and to estimate the cure rate index of the vulcanization process. Equipments like the rubber process analyser (RPA), a dynamic mechanical rheological tester, is a common equipment in the rubber industry. 

Cure time corresponds to the time required for optimum vulcanization of samples. NR filled with different silica types (precipitated silica, PSi and fumed silica, FSi) have been prepared and their cure characteristics features were analyzed. The corresponding data related to the cure characteristics, scorch time (ts2), cure time (tc9o) cure rate index (CRI) and minimum torque (Ml) are recorded in Table 18.10. It can be seen that compared to PSi/NR compounds, degree of reversion and viscosity are higher for FSi/NR compounds at the same... 

Salaeh et al investigated the curing characteristics of the gum rubber compound and the ceramic/NR composites in terms of minimum, maximum and delta torques, scorch time, cure time, and cure rate index (CRI) are summarized in Table 18.11. This suggests that longer cure time but lower CRI in the BaTiOs composites compared with the PbTiOs composites. This indicated lower rate of vulcanization in the BaTi03 compounds. Furthermore,... 

Cure Rate Index - The slope of the linear portion of the rising curve between tsi and t9o. 

A lower cure index represents a faster cure rate. There is a limit, however, to the cure information that a Mooney scorch test can provide as the cure advances beyond rix (for a small rotor) and (for a large rotor). This is because as the specimen cures and builds a cross-linked matrix, it loses flow properties and begins to slip and tear on the rotor [95]. 

In the case of the polyether urethane acrylates, the material properties were varied by the length of the poly(propylene oxide) chain. Increasing the chain length decreases crosslink density and content of polar urethane groups and increases the volume fraction of low T, low refractive index polyether. As a result T, refractive index and E-modulus decrease. The addition of a small amount of reactive diluent (g20%) brings the viscosity and the curing rate to the desired level. 

T.I. = therapeutic index (defined as the relation LD50/ED90 when optimum cure rate < 90%, no value is given)... 

Numerous titanocene derivatives ( 5115)271X2 were tested which had been modified at the position of the acido ligands X. Investigating the antitumor activity of titanocene dihalides and bis(pseudohalides) VII-XI revealed compounds which were equally potent as I, the optimum cure rate amounting to 100%. In the case of VIII with X = Br, the therapeutic range was enlarged leading to an increase of the therapeutic index (T.I.) to 4.5 (Fig. 9), compared with 3.3 after application of I. 

Figure 9.28 Curing rate of PPS as monitored through melt flow index. (From Ref. 30.)...

Cme Index, tL, is the difference between the Cure Time and the Scorch Time (tss-ts). It is used as a measiu e of cure rate of the compoimd - the smaller the Cme Index, the faster the cme rate. 

The major use of vinylpyrrohdinone is as a monomer in manufacture of poly(vinylpyrrohdinone) (PVP) homopolymer and in various copolymers, where it frequendy imparts hydrophilic properties. When PVP was first produced, its principal use was as a blood plasma substitute and extender, a use no longer sanctioned. These polymers are used in pharmaceutical and cosmetic appHcations, soft contact lenses, and viscosity index improvers. The monomer serves as a component in radiation-cured polymer compositions, serving as a reactive diluent that reduces viscosity and increases cross-linking rates (see... 

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