Heat capacity of poly-p-dioxanone
Heat capacity of poly-p-dioxanone
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DOI：
10.1080/00222349808220453
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发表时间：
1998-01-01
期刊：
影响因子：
--
通讯作者：
Wunderlich, B
中科院分区：
文献类型：
--
作者：
Ishikiriyama, K;Pyda, M;Wunderlich, B
采用差示扫描量热法（DSC）和温度调制量热法（TMDSC）测定了聚对二恶酮（PPDX） （CH2-CH2-O-CH2-COO-）(x)在200 ~ 430 K范围内的热容。基于新数据和文献数据，采用近似群振动谱和骨架振动分析了固态的热容。温度分别为theta(1) = 478.7 K和theta(3) = 50.4 K的Tarasov函数很好地表示了10种骨架振动模式。该液体的热容拟合为C-p（液体）= 0.1484 T + 144.3的线性函数，单位为J K-1 mol(-1)，这与先前建立的聚氧乙烯和聚乙二醇液体方程的总和接近。非晶PPDX在玻璃化温度（264 K）下的热容变化为69.9 J K-1 mol(-1)，完美晶体在熔化温度（接近400 K）下的熔合热为14.4 kJ mol（-1）。导出了积分热力学函数，并由这些函数确定了玻璃在0 K时的剩余熵，外推为13.4 J K-1 mol(-1)（或2.7 J K-1 mol（-1）每个链原子）。
The heat capacity of poly-p-dioxanone (PPDX), (CH2-CH2-O-CH2-COO-)(x), was determined using both differential scanning calorimetry (DSC) and temperature-modulated DSC (TMDSC) from 200 K to 430 K. Based on the new data and literature data, the heat capacity of the solid state was analyzed using an approximate group vibrational spectrum and skeletal vibrations. The 10 skeletal vibrational modes are well represented by a Tarasov function with theta temperatures of theta(1) = 478.7 K and theta(3) = 50.4 K. The heat capacity of the liquid was fitted to a linear function, C-p(liquid) = 0.1484 T + 144.3 in units of J K-1 mol(-1), which is close to the sum of equations developed earlier for the liquids of poly(oxyethylene) and polyglycolide. The change in heat capacity of amorphous PPDX at the glass transition temperature (264 K) is 69.9 J K-1 mol(-1), and the heat of fusion for perfect crystals at the melting temperature (approximate to 400 K) is 14.4 kJ mol(-1). The integral thermodynamic functions were derived, and the residual entropy of the glass at 0 K, determined from these functions, is extrapolated as 13.4 J K-1 mol(-1) (or 2.7 J K-1 mol(-1) per chain atom).