Fibrillar growth

Fibrillar growth leads to spherulites. Although dendritic growth from... 

The mechanism of fibrillar growth has been interpreted in terms of formation of bundle-like nuclei which grow longitudinally. 

Ziabicki and Jarecki have studied the effect of thermodynamic and hydro-dynamic parameters on the orientation distribution of the nuclei, to explain oriented fibrillar growth. Wu has also taken a thermodynamic approach to stress induced crystallization of cross-linked rubbers and its effect on morphology. He considers that extended chain crystals are only formed above the zero-strained melting point, Tva, and folded crystals are formed below Tm if the molecules are stretched less than some critical amount. 

Figure 4.5 The dependence of parameter (1 - x/Kfj on the relative duration t of crystallisation (1, 2) - theoretical limiting curves for lamellar and fibrillar growth of crystallites, respectively [39] the experimental curves at X= (3) 1.5 (4) 2 (5) 3...

They therefore finally appear as polyhedra. Because of their radial growth the fibrillar or lamellar crystals have only little space-filling ability as they move away from the central nucleus. Typically for spherulitic structures, an irregular noncrystallo-graphic branching usually at small angles can be observed. 

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