Thermorheological analysis of PVC blends

✍ Scribed by A. Zárraga; J. J. Peña; M. E. Muñoz; A. Santamaría

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 268 KB
• Volume: 38
• Category: Article
• ISSN: 0887-6266
• DOI: 10.1002/(sici)1099-0488(20000201)38:3<469::aid-polb12>3.0.co;2-r

✦ Synopsis

The effect of temperature on dynamic viscoelastic measurements of miscible poly (vinyl chloride) (PVC)/ethylene-vinyl acetate-carbon monoxide terpolymer (EVA-CO) and immiscible PVC/high-density polyethylene (HDPE) and PVC/chlorinated polyethylene (CPE) molten blends is discussed. PVC plasticized with di(2 ethyl hexyl) phthalate (PVC/DOP) and CaCO 3 filled HDPE (HDPE/CaCO 3 ) are also considered for comparison purposes. Thermorheological complexity is analyzed using two time-temperature superposition methods: double logarithmic plots of storage modulus, GЈ, vs. loss modulus, GЉ, and loss tangent, tan ␦, vs. complex modulus, G*, plots. Both methods reveal that miscible PVC/EVA-CO and PVC/DOP systems are thermorheologically complex, which is explained by the capacity of PVC to form microdomains or crystallites during mixing and following cooling of the blends. For immiscible PVC/ HDPE and PVC/CPE blends the results of log GЈ vs. log GЉ show temperature independence. However, when tan ␦ vs. log G* plots are used, the immiscible blends are shown to be thermorheologically complex, indicating that the morphology observed by microscopy and constitued by a PVC phase dispersed in a HDPE or CPE matrix, is reflected by this rheological technique.