Show simple item record

dc.contributorVirginia Techen_US
dc.contributor.authorJerman, R. E.en_US
dc.contributor.authorBaird, Donald G.en_US
dc.date.accessioned2014-03-26T17:35:16Z
dc.date.available2014-03-26T17:35:16Z
dc.date.issued1981
dc.identifier.citationJ. Rheol. 25, 275 (1981); http://dx.doi.org/10.1122/1.549645
dc.identifier.issn0148-6055
dc.identifier.urihttp://hdl.handle.net/10919/46805
dc.description.abstractRheological properties of two copolyesters which exhibit liquid crystalline behavior in the melt state were determined using an Instron capillary rheometer. The two polymer melts with nematic liquid crystalline order consisted of copolymers of polyethylene terephthalate (PET) and 60 and 80 mole % of p_hydroxybenzoic acid (PHB). Data was also obtained on PET which was used as a control. Measurements included the temperature and shear rate dependence of viscosity, entrance pressure losses (_Pent), and die swell (Dj/D). The viscosity of the liquid crystalline melts are as much as two orders of magnitude less than those of PET at temperatures at which they are ordinarily processed. The extrudate actually contracts at the lower end of processing temperatures but does increase to values greater than one with increasing temperature for the liquid crystalline polymers. Although the die swell data indicate that there is negligible elastic recovery at the capillary exit, values of the ratio of _Pent to wall shear stress (_w) are considerably higher for liquid crystalline melts than for PET. Some explanation of these data is presented but more rheological measurements are needed before our understanding of these unique systems is complete.
dc.description.sponsorshipArmy Research Office DAAG29-80-K-0093
dc.language.isoen_US
dc.publisherAIP Publishing
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.titleRheological Properties Of Copolyester Liquid-Crystalline Melts .1. Capillary Rheometryen_US
dc.typeArticle - Refereeden_US
dc.contributor.departmentBiomedical Engineering and Mechanicsen_US
dc.contributor.departmentChemical Engineeringen_US
dc.identifier.urlhttp://scitation.aip.org/content/sor/journal/jor2/25/2/10.1122/1.549645
dc.date.accessed2014-03-11
dc.title.serialJournal of Rheology
dc.identifier.doihttps://doi.org/10.1122/1.549645
dc.type.dcmitypeTexten_US


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record