Effect of the UV stabilization on mechanical properties

These considerations enabled us to study the effect of the stabilizer addition on samples of smaller thickness (0.3 mm). The data on the behaviour of these specimens from the viewpoint of mechanical properties are shown in Table 4.25. 

Final PU elastomer containing molecular dispersed HO-A-OH (0.58%) where M = polyethylene adipate 

UV Absorber PU composition Mechanical measurements 7 Time (days) 30 60 90 120 

Overall, it could be concluded that the addition of UV stabilizer l,2-bis[2-(2-hydroxy-5-methylphenyl)-5-benzotriazolyl]ethane (BHMBE) to the prepolymer step of the studied PUs can be used successfully [64]. TheUV absorber first formed a temporary chemical binding as a result of the addition reaction between OH phenolic groups and the isocyanate groups belonging to the prepolymer. During 

This method of mixing the UV absorber with PUs was used without damage or significant decrease of mechanical properties. The presence of BHMBE determined temperate stabilization effects. In this first stage of our research the influence of the stabilizer of a concentration range up to 1% in polymer was studied [64]. 

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