STUDIES IN THE CONTROL OF PROPERTIES OF POLYURETHANE FOAMS
STUDIES IN THE CONTROL OF PROPERTIES OF POLYURETHANE FOAMS
| dc.contributor.author | OKORO , OGBOBE AUGUSTINE | |
| dc.date.accessioned | 2015-06-10T10:45:46Z | |
| dc.date.available | 2015-06-10T10:45:46Z | |
| dc.date.issued | 1979-02 | |
| dc.description.abstract | There are a lot of local polyurethane foam manufacturers in Nigeria who appear not to have properly correlated the effect of the various foam ingredients on foam properties. The effect of some of the variables in polyurethane foam preparation on foam properties have been investigated, Excess Tolylene di-isocyanate (TDI) in flexible polyurethane foam formulation has no significant effect on physical properties but trace amounts of water in the form of moisture can affect foam properties significantly. Trace amounts of sodium hydroxide solution and sodium bicarbonate in flexible foam formulations respectively catalyze polyurethane foam reactions and give rise to crumbling foams. Increasing amount of freon used with a fixed amount of water gives foams of better appearance than when water is used alone. It was also observed that increase in rise height decreases foam density while tensile stress at break and initial modulus are high at low rise heights. Flexible foams have low compressive stresses before stiffening occurs and a pronounced yield point which decreases with decrease xii. in density. Flexible fcaras have a comparatively low hysteresis loss and hence good resilience. The density of rigid foams decrease with increase in blowing agent concentration. Rigid foams have high compressive stresses, undefined yield points and large hysteresis losses. The thermal conductivity of rigid foams (density 34-23 kgm ) increased with decrease in foam density. | en_US |
| dc.identifier.uri | http://hdl.handle.net/123456789/6626 | |
| dc.language.iso | en | en_US |
| dc.subject | POLYURETHANE FOAMS | en_US |
| dc.subject | POLYURETHANE FOAMS | en_US |
| dc.title | STUDIES IN THE CONTROL OF PROPERTIES OF POLYURETHANE FOAMS | en_US |
| dc.type | Thesis | en_US |