| 000 | 02222nam a2200265Ia 4500 | ||
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| 003 | MX-MdCICY | ||
| 005 | 20250625140653.0 | ||
| 040 | _cCICY | ||
| 090 | _aB-11590 | ||
| 245 | 1 | 0 | _aExperimental study of shear-induced crystallization of an impact polypropylene copolymer |
| 490 | 0 | _vColloid & Polymer Science, 274, p.197-208, 1996 | |
| 520 | 3 | _aThe crystallization kinetics of polypropylene was observed during shear and after shear experiments under isothermal condition. The crystallizations were performed in a plate-plate and a fiber pull-out device. The nucleation density, the crystalline growth and the overall kinetics were measured and compared with data obtained in a similar way but during static experiments. The morphologies are spherulitic and formed from nuclei which seem to be randomly distributed, a-phase spherulites are always observed but with a nucleation density and a growth rate which depend on shearrate. The nucleation density is strongly enhanced by shear and acts as the main factor on the overall kinetics. The overall kinetics can be analyzed with a two-step Avrami model, where an Avrami exponent n~ with a very high value is always observed first after shear and a more usual parameter n2 for the subsequent crystallization period. This high value of n~ seems to be related to the strong enhancement of nucleation density. The growth rate increases with the shear-rate, but the basic growth mechanisms do not seem to be modified. For crystallizations after shear the growth rate decreases with a long-time delay after shear but not down to the static value. The effect is characteristic of a partial relaxation of chain orientation after shear but with a very unusual time constant. | |
| 650 | 1 | 4 | _aSHEAR-INDUCED CRYSTALLIZATION |
| 650 | 1 | 4 | _aNUCLEATION |
| 650 | 1 | 4 | _aGROWTH |
| 650 | 1 | 4 | _aOVERALL KINETICS |
| 650 | 1 | 4 | _aPOLYMER |
| 650 | 1 | 4 | _aPOLYPROPYLENE |
| 700 | 1 | 2 | _aTribout, C. |
| 700 | 1 | 2 | _aMonasse, B. |
| 700 | 1 | 2 | _aHaudin, J.M. |
| 856 | 4 | 0 |
_uhttps://drive.google.com/file/d/1bZVWG_GSfe6HPf0fnH7TQxMIQxhXeKKA/view?usp=drivesdk _zPara ver el documento ingresa a Google con tu cuenta: @cicy.edu.mx |
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