High pressure jump apparatus for measuring Grűneisen parameter of NaCl and studying metastable amorphous phase of poly (ethylene terephthalate)

2005 ◽  
Vol 76 (5) ◽  
pp. 053905 ◽  
Author(s):  
S. M. Hong ◽  
L. Y. Chen ◽  
X. R. Liu ◽  
X. H. Wu ◽  
L. Su
Keyword(s):  
High Pressure ◽  
Amorphous Phase ◽  
Ethylene Terephthalate ◽  
Pressure Jump ◽  
Grüneisen Parameter ◽  
Gruneisen Parameter ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene

Constant-Temperature Embossing of Amorphous Poly(Ethylene Terephthalate) Films

2007 ◽  
Author(s):  
Donggang Yao ◽  
Pratapkumar Nagarajan ◽  
K. R. T. Ramasubramani
Keyword(s):  
Thermal Cycling ◽  
Amorphous Phase ◽  
Constant Temperature ◽  
Ethylene Terephthalate ◽  
Mold Temperature ◽  
Cycle Times ◽  
Poly Ethylene Terephthalate ◽  
Micro Features ◽  
Poly Ethylene ◽  
Pet Film

In the standard hot embossing process for thermoplastic polymers, thermal cycling is needed in order to soften and subsequently cool and solidify the polymer. This thermal cycling, however, not only results in long cycle times but also deteriorates the quality of embossed features. A new embossing method based on slowly crystallizing polymers was investigated to eliminate thermal cycling. Poly(ethylene terephthalate) was used as a model system for demonstration. Due to its slow crystallization, amorphous PET film can be made by casting a PET melt onto a chill roll. The amorphous PET film was embossed at a constant temperature of 180°C for a period of time comparable to or longer than PET’s half-time of crystallization. During constant-temperature embossing, the film first liquefies, caused by rubber softening of the amorphous phase, and then solidifies, resulting from the crystallization of the amorphous phase. Since the embossed film is hardened under the constant mold temperature, no cooling is needed. Selected micro features, including circular microchannels and high aspect ratio rectangular microchannels, were successfully embossed using a total cycle time about 40 s.

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.

scholarly journals Microhardness and structure of high pressure crystallized poly(ethylene terephthalate)

Polymer ◽  
1994 ◽  
Vol 35 (22) ◽  
pp. 4775-4779 ◽  
Author(s):  
F.J. Baltá^Calleja ◽  
O. Öhm ◽  
R.K. Bayer
Keyword(s):  
High Pressure ◽  
Ethylene Terephthalate ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene

Measuring Grüneisen Parameter of Lead by High Pressure-Jump Method

2007 ◽  
Vol 24 (8) ◽  
pp. 2441-2443 ◽  
Author(s):  
Huang Dai-Hui ◽  
Liu Xiu-Ru ◽  
Su Lei ◽  
Hu Yun ◽  
Lv Shi-Jie ◽  
...  
Keyword(s):  
High Pressure ◽  
Pressure Jump ◽  
Grüneisen Parameter ◽  
Gruneisen Parameter
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