Chain extension of poly(ethylene terephthalate) with bisphenol-A dicyanate

2010 ◽  
Vol 117 (4) ◽  
pp. 2003-2008 ◽  
Author(s):  
Yanjun Zhang ◽  
Chen Zhang ◽  
Hangquan Li ◽  
Zhongjie Du ◽  
Congju Li
Keyword(s):  
Bisphenol A ◽  
Ethylene Terephthalate ◽  
Chain Extension ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene

Effects of Chain Extension and Branching on the Properties of Poly (Ethylene-Terephthalate)-Organoclay Nanocomposites

2004 ◽  
Vol 856 ◽  
Author(s):  
Ali Emrah Keyfoglu ◽  
Ulku Yilmazer
Keyword(s):  
Ethylene Terephthalate ◽  
Interlayer Spacing ◽  
Chain Scission ◽  
Chain Extension ◽  
Twin Screw Extrusion ◽  
Poly Ethylene Terephthalate ◽  
Screw Extrusion ◽  
Organically Modified ◽  
Twin Screw ◽  
Poly Ethylene

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.

Fracture and Deformation of Extended-Chain Crystals in Poly(ethylene Terephthalate)/Bisphenol-A Polycarbonate Blends Crystallized at High Pressure

2011 ◽  
Vol 214 ◽  
pp. 301-305
Author(s):  
Jun Lu ◽  
Jiao Jiao Tian ◽  
Dao Peng Zhang ◽  
Rui Huang
Keyword(s):  
High Pressure ◽  
Bisphenol A ◽  
Single Crystals ◽  
Ethylene Terephthalate ◽  
Morphological Observation ◽  
Bisphenol A Polycarbonate ◽  
Extended Chain ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene ◽  
Functional Components

With a combination of three-dimensional crystal ordering and long-chain molecular orientational ordering, the extended-chain crystals of polymers are ideal system for the studies on low-dimensional physics, and have potential applications as functional components. In this study, poly (ethylene terephthalate) / bisphenol-A polycarbonate (PET/BAPC) blend samples were prepared with solid phase forming technique under high pressure, and extended-chain single crystals with large c-axis thickness were formed within a relative short time. The fracture and deformation behaviors of the grownup crystals were investigated using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Morphological observation showed that most of the extended-chain crystals were endowed with perfect appearance after the sample fracture. However, there were still a few crystals fractured apart, along or perpendicularly to their c-axis direction, or with cohesive fracture surfaces. Fractured spherulites with extended-chain lamellae as substructures were also disclosed in extended-chain crystals with AFM. Furthermore, the parallel lamellae deformed and changed their striation direction during the crystal growth, as was observed on a kind of extended-chain crystals grown in a PET oligomer and BAPC blend (PETO/BAPC). This study may be instructive to the improvement of the separation technique of such single crystals, so as to hasten their real applications.

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