Cure schedule, effect

Figure 5. Curing schedule effect on zero stress temperature.

To determine the effect of the curing schedule upon the thermal stress development, a 0% excess MDA sample was made by first B-stage curing (2 hrs at 80°C) the sample, cutting it into the beam dimensions and then placing it in the apparatus. The deflection of the beam was measured during the remainder of the curing schedule (2 hrs at 150°C and 2 hrs at 180°C). 

The purpose of the study was a) to determine the effect of relative resin/hardener composition and ambient and elevated temperature curing schedules on the glass transition temperature, Tg, and on the degree of cure of the epoxy system, and b) to evaluate the agreement between the calculated degree of cure using the nth-order kinetic equation (1.1) (1, 2, 3) and the measured degree of cure. 

Table 2.10 Effect of cure schedule on Tg and CTE for an epoxy adhesive ...

The mixing procedure, preparation conditions and cure schedule all have a profound effect on the mechanical properties of the adhesives and, consequently, will affect their durability [20, 73]. Because of this, expeditious on-site tests should be conducted to detect possible deficiencies. A number of test methods have been proposed by the CEN/TC193/SC1/WG11) in the pre-standard Adhesives for on-site assembling or restoration of timber structures — on-site acceptance testing . This... 

The values of Poisson s ratio for some polymeric materials are shown in Table I. The stress-strain characteristics for several cured commercial structural adhesives were determined by Schjeldrup and Jones. These workers found that the modulus, at room temperature, for epoxy-based commercial adhesives varied in the range 322-375 ksi, while the ultimate stresses varied from 6,050 to 7,853 ksi and the ultimate strains varied from 2.4 to 15.6%. Sancaktar et al. investigated the effect of cure schedule on the tensile properties of a commercial structural adhesive. They found that the ultimate stress and modulus were higher for a longer, lower-temperature cure... 

Hamerton Ian, Tang Winnie, Anguita Jose V., and Silva S. Ravi P. Towards the rational design of polymers using molecular simulation Predicting the effect of cure schedule on thermo-mechanical properties for a cycloaliphatic amine-cured epoxy resin. React. Funct. Polym. 74 no. (2014) 1—15. 

In the treatment of S haematobium, an oral dose of 7.5-10 mg/kg is given three times at 14-day intervals. Cure rates on this schedule are 44-93%, with marked reductions in egg counts in those not cured. Metrifonate was also effective as a prophylactic agent when given monthly to children in a highly endemic area, and it has been used in mass treatment programs. In mixed infections with S haematobium and S mansoni, metrifonate has been successfully combined with oxamniquine. 

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