Thermal Properties of Aliphatic Polypeptoids
Thermal Properties of Aliphatic Polypeptoids
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DOI：
10.3390/polym5010112
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发表时间：
2013-03-01
期刊：
影响因子：
5
通讯作者：
Luxenhofer, Robert
中科院分区：
文献类型：
--
作者：
Fetsch, Corinna;Luxenhofer, Robert
研究了一系列聚合度为10-100的短（C-1-C-5）侧链的类多肽均聚物的热稳定性、玻璃化转变和熔点。类多肽的热重分析表明稳定性>200 ℃。通过差示扫描量热法对玻璃化转变温度的研究揭示了两种依赖性。一方面，通过恒定聚合度的侧链的延伸降低玻璃化转变温度（T-g），另一方面，通过恒定侧链长度的聚合度的提高导致T-g增加到恒定值。观察到具有包含不少于三个甲基碳原子的侧链的类多肽的熔点。聚肌氨酸和聚（N-乙基甘氨酸）的X射线衍射证实了所观察到的熔点的缺乏，因此，它们的无定形性质。其他研究的类多肽的衍射图表明聚合物粉末中存在结晶域。
A series of polypeptoid homopolymers bearing short (C-1-C-5) side chains of degrees of polymerization of 10-100 are studied with respect to thermal stability, glass transition and melting points. Thermogravimetric analysis of polypeptoids suggests stability to >200 degrees C. The study of the glass transition temperatures by differential scanning calorimetry revealed two dependencies. On the one hand an extension of the side chain by constant degree of polymerization decrease the glass transition temperatures (T-g) and on the other hand a raise of the degree of polymerization by constant side chain length leads to an increase of the T-g to a constant value. Melting points were observed for polypeptoids with a side chain comprising not less than three methyl carbon atoms. X-ray diffraction of polysarcosine and poly(N-ethylglycine) corroborates the observed lack of melting points and thus, their amorphous nature. Diffractograms of the other investigated polypeptoids imply that crystalline domains exist in the polymer powder.