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首页> 外文期刊>Journal of Applied Polymer Science >THE INFLUENCE OF THERMAL HISTORY ON THE PROPERTIES OF POLY(3-HYDROXYBUTYRATE-CO-12-PERCENT-3-HYDROXYVALERATE)
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THE INFLUENCE OF THERMAL HISTORY ON THE PROPERTIES OF POLY(3-HYDROXYBUTYRATE-CO-12-PERCENT-3-HYDROXYVALERATE)

机译：热历史对聚（3-羟基丁酸酯-CO-12-百分数-3-羟基戊酸酯）性能的影响

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摘要

The influence of thermal history on the properties of commercial P(3HB-co-12%-3HV) was studied. Thermogravimetric analysis and differential scanning calorimetry revealed that the plasticizer evaporated at 140 degrees C or higher. The loss of plasticizer during thermal treatment at, 170 and 180 degrees C resulted in a slight increase of the melting temperature of the polymer. The processing time and temperature, as well as the cooling procedure influenced the thermal behaviour of the material. A decrease in molecular weight with time was found at the temperatures investigated and this significantly affected the mechanical properties of the polymer prepared at 180 and 200 degrees C. The rate constant k(d) of thermal degradation was slightly higher for samples during a shape-forming process in a Minimax apparatus than during a quiescent heating process (DSC) and its value increased with temperature. Limiting the processing at 170 degrees C to 2 min gave a material with useful properties but in creasing the residence time resulted in a decrease in strength, elongation at break, molecular weight and viscosity although it did not significantly influence the modulus of elasticity. Materials prepared at 180 or 200 degrees C were more brittle and longer residence times resulted in a deterioration of the mechanical properties. (C) 1996 John Wiley & Sons, Inc. [References: 33]
机译：研究了热历史对商用P（3HB-co-12％-3HV）性能的影响。热重分析和差示扫描量热法显示增塑剂在140℃或更高温度下蒸发。在170和180摄氏度的热处理过程中，增塑剂的损失导致聚合物的熔融温度略有提高。处理时间和温度以及冷却程序影响了材料的热性能。在所研究的温度下，分子量随时间降低，这显着影响了在180和200摄氏度下制备的聚合物的机械性能。在形状加工过程中，样品的热降解速率常数k（d）略高。与静态加热过程（DSC）相比，在Minimax设备中进行成型过程，其值随温度而增加。将加工温度限制在170摄氏度到2分钟可得到一种具有有用性能的材料，但停留时间的增加会导致强度，断裂伸长率，分子量和粘度的降低，尽管它不会显着影响弹性模量。在180或200摄氏度下制备的材料更脆，停留时间更长，导致机械性能下降。 （C）1996 John Wiley＆Sons，Inc. [参考：33]

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