利用示差扫描量热仪(DSC)分析了3种不同分子量的聚己内酯(PCL)在30～45℃的等温结晶,并通过Avrami方程对其进行了等温结晶动力学研究.在此温度范围内,PCL的结晶度与等温结晶时间的关系曲线都呈现S型,说明其均采用异相成核的方式.根据Avrami关系式解出的双对数图都存在很好的直线关系部分, 推导出Avrami指数(n)的值大都约为整数,在相同的Tc下,PCL生长方式类似,与分子量基本无关.lnK(结晶速率常数)随Tc的升高逐渐减小,说明晶体生长速率逐渐下降.在相同的Tc下,随着分子量的增加,结晶速率逐渐下降.半结晶时间(t1/2)随Tc的升高而降低,说明在此温度范围内晶体的生长速率随着Tc的升高而减慢.通过原子力显微镜(AFM)研究了PCL在30～45℃等温结晶的晶体表面,推导出的n值与Avrami方程拟合出的n值基本一致,说明Avrami动力学分析的结果是比较可靠的.
参考文献
| [1] | 朱光明,梁国正,费敬银,马晓燕,张龙彬.聚己内酯/聚酯丙烯酸酯共混物的辐射交联及其形状记忆行为[J].高分子学报,2005(02):275-280. |
| [2] | Lin J;Zhu J;Chen .Drug releasing behavior of hybrid micelles containing polypeptide triblock copolymer.[J].Biomaterials,2009(1):108-117. |
| [3] | Blacker T D;Stephenson M B .A new approach to automated quadrilateral mesh generation[J].International Journal for Numerical Methods in Engineering,1991,32(04):811. |
| [4] | Ruetschi P .Alkaline aqueous electrolyte cells for biomedical applications[J].Journal of the Electrochemical Society,1980,127(08):1667. |
| [5] | 黄发荣.聚合物材料再循环利用的研究与进展[J].高分子材料科学与工程,1997(02):132-138. |
| [6] | Nojima S;Kikuchi N;Rohadi A et al.Melting behavior of poly(epsilon-caprolactone)-block-polybutadiene copolymers[J].Macromolecures,1999,32(11):3727. |
| [7] | Nojima S.;Tanimoto S.;Nakatani H.;Sasaki S.;Kakihira H. .Crystallization of poly(epsilon-caprolactone)-block-polystyrene copolymers from glassy microdomain structures[J].Polymer Journal,2000(1):75-78. |
| [8] | Nojima S;Kiji T;Ohguma Y .Characteristic melting behavior of double crystalline poly(epsilon-caprolactone)-block-polyethylene copolymers[J].Macromolecules,2007,40(20):7566. |
| [9] | Bogdanov B.;Schacht E.;Berghmans H.;Vidts A. .Isothermal crystallization of poly(ε-caprolactone-ethylene glycol) block copolymers[J].Macromolecules,1999(3):726-731. |
| [10] | Albuerne J.;Marquez L.;Muller AJ.;Raquez JM.;Degee P.;Dubois P. .Nucleation and crystallization in double crystalline poly(p-dioxanone)-b-poly(epsilon-caprolactone) diblock copolymers[J].Macromolecules,2003(5):1633-1644. |
| [11] | Phillips P J;Rensch G;Sorenson D .Crystallization studies of poly(ε-caprolactone) as a function of molecular-weight and temperature[J].Bulletin of the American Physical Society,1979,24(03):348. |
| [12] | Phillips P J;Rensch G J;Kevin D .Crystallization studies of poly(ε-caprolactone)Ⅰ.Morphology and kinetics[J].Journal of Polymer Science Part B:Polymer Physics,1987,25(08):1725. |
| [13] | Heck B.;Strobl GR.;Sadiku ER. .SAXS and DSC studies of the crystallization and melting phenomena of poly(epsilon-caprolactone)[J].Macromolecular symposia,2001(0):99-113. |
| [14] | Heck B;Hugel T;Iijima M et al.Steps in the transition of an entangled polymer melt to the partially crystalline state[J].New Journal of Physics,1999,17(01):1. |
| [15] | Strobl G.Polymer physics[M].Heidelberg:Springer-Verlag,1997:143. |
| [16] | Sun Y S;Chung T M;Li Y J et al.Crystalline polymers in nanoscale 1D spatial confinement[J].Macromolecules,2006,39(01):5782. |
| [17] | Wunderlich B.Macromolecular physics,crystal nucleation,growth,annealing[M].New York:Academic Press,Inc,1976:176. |
| [18] | Zhu L;Cheng S Z D;Calhoun B H et al.Initial-stage growth controlled crystal orientations in nanoconfined lamellae of a self-assembled crystalline-amorphous diblock copolymer[J].Polymer,2001,42(03):5829. |
上一张
下一张
上一张
下一张
计量
- 下载量()
- 访问量()
文章评分
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%