Abstract
The semicrystalline morphology of a poly (butylene terephthalate) was formed under the shear, pressure, and thermal gradients of the injection-molding process, and subsequently studied regarding the crystallinity of the skin layer and the core using fast scanning chip calorimetry (FSC) and microfocus X-ray diffraction. Test bars of 3 mm thickness were molded via a broad tab gate at one end of the part, designed to facilitate a linear flow path and to minimize shearing of the polymer as it passes through the gate. Simulation of the injection-molding process suggests a gradient in the cooling rate through the test part that varies from 50 K s−1 100 µm below the surface to 10 K s−1 in the core, at the temperature of crystallization after the cessation of flow. Analysis of the crystallinity reveals skin and core crystallinities of 35 and 46 %, respectively, near the gate, while there were observed values of 42 and 48 % at the end of fill; XRD data consistently confirmed the crystallinity difference between skin and core, and between the near and far gate positions. The observed cooling-rate-controlled crystallinity values are in excellent agreement with data of the degree and kinetics of quiescent melt-crystallization obtained in a former study. For the first time, the reliability of FSC data obtained during first heating, in order to gain thermal-history/processing-controlled structure information, is demonstrated.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 939-946 |
| Number of pages | 8 |
| Journal | Journal of Thermal Analysis and Calorimetry |
| Volume | 127 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 1 2017 |
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All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Physical and Theoretical Chemistry
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Skin/core crystallinity of injection-molded poly (butylene terephthalate) as revealed by microfocus X-ray diffraction and fast scanning chip calorimetry. / Rhoades, Alicyn Marie; Williams, Jason Louis; Wonderling, Nichole M.; Androsch, René; Guo, Jiaxi.
In: Journal of Thermal Analysis and Calorimetry, Vol. 127, No. 1, 01.01.2017, p. 939-946.Research output: Contribution to journal › Article
TY - JOUR
T1 - Skin/core crystallinity of injection-molded poly (butylene terephthalate) as revealed by microfocus X-ray diffraction and fast scanning chip calorimetry
AU - Rhoades, Alicyn Marie
AU - Williams, Jason Louis
AU - Wonderling, Nichole M.
AU - Androsch, René
AU - Guo, Jiaxi
PY - 2017/1/1
Y1 - 2017/1/1
N2 - The semicrystalline morphology of a poly (butylene terephthalate) was formed under the shear, pressure, and thermal gradients of the injection-molding process, and subsequently studied regarding the crystallinity of the skin layer and the core using fast scanning chip calorimetry (FSC) and microfocus X-ray diffraction. Test bars of 3 mm thickness were molded via a broad tab gate at one end of the part, designed to facilitate a linear flow path and to minimize shearing of the polymer as it passes through the gate. Simulation of the injection-molding process suggests a gradient in the cooling rate through the test part that varies from 50 K s−1 100 µm below the surface to 10 K s−1 in the core, at the temperature of crystallization after the cessation of flow. Analysis of the crystallinity reveals skin and core crystallinities of 35 and 46 %, respectively, near the gate, while there were observed values of 42 and 48 % at the end of fill; XRD data consistently confirmed the crystallinity difference between skin and core, and between the near and far gate positions. The observed cooling-rate-controlled crystallinity values are in excellent agreement with data of the degree and kinetics of quiescent melt-crystallization obtained in a former study. For the first time, the reliability of FSC data obtained during first heating, in order to gain thermal-history/processing-controlled structure information, is demonstrated.
AB - The semicrystalline morphology of a poly (butylene terephthalate) was formed under the shear, pressure, and thermal gradients of the injection-molding process, and subsequently studied regarding the crystallinity of the skin layer and the core using fast scanning chip calorimetry (FSC) and microfocus X-ray diffraction. Test bars of 3 mm thickness were molded via a broad tab gate at one end of the part, designed to facilitate a linear flow path and to minimize shearing of the polymer as it passes through the gate. Simulation of the injection-molding process suggests a gradient in the cooling rate through the test part that varies from 50 K s−1 100 µm below the surface to 10 K s−1 in the core, at the temperature of crystallization after the cessation of flow. Analysis of the crystallinity reveals skin and core crystallinities of 35 and 46 %, respectively, near the gate, while there were observed values of 42 and 48 % at the end of fill; XRD data consistently confirmed the crystallinity difference between skin and core, and between the near and far gate positions. The observed cooling-rate-controlled crystallinity values are in excellent agreement with data of the degree and kinetics of quiescent melt-crystallization obtained in a former study. For the first time, the reliability of FSC data obtained during first heating, in order to gain thermal-history/processing-controlled structure information, is demonstrated.
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U2 - 10.1007/s10973-016-5793-z
DO - 10.1007/s10973-016-5793-z
M3 - Article
AN - SCOPUS:84984801511
VL - 127
SP - 939
EP - 946
JO - Journal of Thermal Analysis and Calorimetry
JF - Journal of Thermal Analysis and Calorimetry
SN - 1388-6150
IS - 1
ER -