scholarly journals THE FINE STRUCTURE AND PHYSICAL PROPERTIES OF COPOLYMER FIBER OF POLY-P-PHENYLENETEREPHTHALAMIDE

1978 ◽  
Vol 34 (8) ◽  
pp. T342-T348
Author(s):  
Kazuyuki Yabuki ◽  
Hajime Koda ◽  
Seiji Endo ◽  
Ikuo Kajima ◽  
Keiji Yukimatsu ◽  
...  
1981 ◽  
Vol 59 (5) ◽  
pp. 640-648 ◽  
Author(s):  
G. R. Lister ◽  
B. W. Thair

The epicuticular leaf wax of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) was recrystallized from chloroform solution in vitro. The striated, tubular forms were reconstituted in sizes which included that observed in vivo, indicating that the final dimensions and morphology of the wax crystals are functions of physical properties of the component molecules, rather than an enzyme-dependent polymerization. Subsequent evaluation of all observations and data formed the basis for the scale construction of a model of the tubular wax crystal.


e-Polymers ◽  
2003 ◽  
Vol 3 (1) ◽  
Author(s):  
Hee Lee Sun ◽  
Hou Kim Kyoung ◽  
Kikutani Takeshi ◽  
Hok Cho Hyun

Abstract Poly(butylene terephthalate) (PBT) fibres were obtained by high-speed melt spinning up to a take-up velocity of 8 km/min. Fine structure formation and physical properties of these fibres were investigated. The increase of take-up velocity caused raises in both density and birefringence. In wide-angle X-ray diffraction equatorial profiles, the increase of take-up velocity can be observed in the (010) and (100) reflections of β-crystals; the reflection peaks are the sharpest at a take-up velocity of 6 km/min. The initial modulus of the fibres arises when the fraction of β-crystals is increased, while the tenacity depends more on the fraction of α-crystals, i.e., the total crystallinity. Thermal properties of high-speed spun PBT fibres were measured with differential scanning calorimetry, dynamic mechanical and thermo-mechanical analysis, etc. Endothermic curves become sharper with increasing take-up velocity, and endothermic melting peaks are shifted to higher temperature. Crystal structures are well developed in fibres obtained at higher take-up velocities. The tan δ peaks of PBT fibres tend to shift to higher temperature and the peak intensity is decreased with increasing take-up velocity, i.e., the packing density of PBT fibres is high when the take-up velocity and thus the orientation of amorphous regions is increased. The shrinkage has a tendency to decrease with increasing take-up velocity.


As is the case with all physical properties, the mechanical properties of an object may be referred ultimately to the arrangement of its atoms and the forces between them. It is therefore possible under certain con­ditions to draw conclusions about the fine structure of an object from its mechanical behaviour. The analysis of thermoelastic properties in particular has led, in a number of cases, to definite conclusions about molecular structure, and it has been the object of the work described here to apply the same method to the study of muscle.


2019 ◽  
Vol 59 ◽  
pp. 104709 ◽  
Author(s):  
Wenhan Yang ◽  
Xiangli Kong ◽  
Yuxue Zheng ◽  
Weixuan Sun ◽  
Shiguo Chen ◽  
...  

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Sunhee Lee ◽  
Kazuo Nakayama ◽  
Hyunhok Cho

AbstractPBT sheets were extruded from T-die using a single extruder and were winded by a take-up roller controlled at 50°C and with speed at 1.2 m/min. Oriented PBT sheets were prepared with various winding roll speeds at 3.6, 4.8 and 6.0 m/min. Fine structure and physical properties of PBT sheets thus obtained were investigated by measuring the molecular orientation, crystal structure, dynamic visco-elasticity, thermal and mechanical properties, sonic modulus, etc. PBT melts were found to be readily crystallizable in the sheet. In the case of roll drawing, the DRmax of PBT sheet was 5. The PBT sheets prepared from winding speed at 6 m/min showed polymorphism of both α- and β-form crystallites with crystallinity of about 24%. In the tri-directional WAXD patterns, the PBT sheets by the roll drawing method turned out to be oriented in the uniplanar-axial form. For the roll drawn PBT sheets with various winding speeds, large orientation effects were observed in the winding direction together with improved thermal and mechanical properties.


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