The effects of long chain branching of polypropylene and chain extension of poly(ethylene terephthalate) on the thermal behavior, rheology and morphology of their blends

RSC Advances ◽  
2015 ◽  
Vol 5 (28) ◽  
pp. 21620-21628 ◽  
Author(s):  
Yousef Jahani ◽  
Milad Ghetmiri ◽  
Mohammad Rahim Vaseghi

Polypropylene is long chain branched, PET is chain extended/branched and their blends are prepared and studied.

2004 ◽  
Vol 856 ◽  
Author(s):  
Ali Emrah Keyfoglu ◽  
Ulku Yilmazer

ABSTRACTThe effects of chain extension and branching on the properties of nanocomposites produced from recycled poly (ethylene-terephthalate) and organically modified clay were investigated. As the potential chain extension/branching agent, maleic anhydride (MA) and pyromellitic dianhydride (PMDA) were used. The nanocomposites were prepared by twin-screw extrusion, followed by injection molding. Recycled poly (ethylene-terephthalate) was mixed with 2, 3 or 4 weight % of organically modified montmorillonite. During the second extrusion step, 0.5, 0.75 or 1 weight % of MA or PMDA was added to the products of the first extrusion. The effects of the sequence of addition of the ingredients on the final properties of the nanocomposites were also investigated. X-Ray Diffraction analysis showed that, the interlayer spacing of Cloisite 25A expanded from 19.21 Å to about 28–34 Å after processing with polymer indicating an intercalated structure. PMDA content, MA content and screw speed did not have a significant effect on the expanded interlayer distance. In the first extrusion step, nanocomposites containing 3% organoclay content gave significant increase in Young's modulus and decrease in elongation at break values indicating good interfacial adhesion. After the addition of anhydrides, it was observed that, in general PMDA improved the mechanical properties of the nanocomposite owing to the branching and chain extension effects that increase the molecular weight. However, MA did not significantly improve the properties, since in this case the chain scission seemed to be more dominant.


1989 ◽  
Vol 171 ◽  
Author(s):  
Robert Kosfeld ◽  
Frank Schubert ◽  
Michael Hess ◽  
Witold Brostow

ABSTRACTThe investigation of the thermal behavior of polymer blends leads to phase diagrams which involve Important information about the system. From these diagrams, equilibrium as well as non-equilibrium phases can be deduced and ranges of miscibility or partial miscibility of the polymers become obvious. Hence the diagrams are of a great value for processing of advanced polymer blends, especially If a polyphasic polymers such as a polymer liquid crystal is one of the constituents of the system.


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