Academic Journal
Optimising Performance of Polyurethane Elastomeric Products Via Control of Chemical Structure
| العنوان: | Optimising Performance of Polyurethane Elastomeric Products Via Control of Chemical Structure |
|---|---|
| المؤلفون: | Cristina Prisacariu, Elena Scortanu, Victor A. Prisacariu |
| المساهمون: | The Pennsylvania State University CiteSeerX Archives |
| المصدر: | http://www.iaeng.org/publication/WCE2009/WCE2009_pp1420-1425.pdf. |
| سنة النشر: | 2009 |
| المجموعة: | CiteSeerX |
| الوصف: | —The overall objective of the present study was to improve understanding of the relation between molecular architecture and mechanical properties / thermal behaviour for a large series of polyurethane copolymers, in which there was systematic variation of the four key chemical features: hard segments based on different geometries, soft segments, low molecular mass diols acting as chain extenders and degree of crosslinking [isocyanic index 100 % (no crosslinking) or 110% (crosslinking)]. The specific aims were to characterize the materials with respect to the aspects of mechanical response and thermal behaviour of practical interest; and to use microstructural information to assist in the interpretation. A major structural feature which has been explored was the nature of the hard segment (crystallising or not); and the effect of increasing the hard segment percent on the mechanical response. The mechanical and thermal performance of these materials as elastomers was shown to vary greatly depending on the composition. When the diisocyanate of variable geometry 4,4’-dibenzyl diisocyanate (DBDI) was employed as hard segment with ethylene glycol (EG) or 1,4-butanediol (BG) (but not diethylene glycol DEG) as chain extender, there was crystallisation of the hard segments, and this caused a large increase in the stress on loading to any given extension. The presence of DBDI as hard segment also lead to a significant reduction in relative energy recovery compared to other conventional rigid diisocyanates – a fact of considerable importance for materials such as the polyurethanes with potential as elastomers. These trends were visible irrespective of the choice of soft segment and whether the polymer was crosslinked or not. All of the polymers kept their elasticity modulus very well on heating. Materials characterized by the presence of accumulated DEG-DBDI blocks displayed a higher resistance at temperatures situated around 140°C. Index Terms — polyurethanes, mechanical properties, thermal behavior, structural ... |
| نوع الوثيقة: | text |
| وصف الملف: | application/pdf |
| اللغة: | English |
| Relation: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.148.9179; http://www.iaeng.org/publication/WCE2009/WCE2009_pp1420-1425.pdf |
| الاتاحة: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.148.9179 http://www.iaeng.org/publication/WCE2009/WCE2009_pp1420-1425.pdf |
| Rights: | Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
| رقم الانضمام: | edsbas.31A545D8 |
| قاعدة البيانات: | BASE |
| الوصف غير متاح. |