Optical property modifiers/nucleating

Nucleating Agents (optical property modifiers) Increasing crystallinity ... 

Nucleating agents help to increase crystallinity in crystallisable polymer systems, and thus they also can be considered as optical property modifiers . 

Polypropylene molecules repeatedly fold upon themselves to form lamellae, the sizes of which ate a function of the crystallisa tion conditions. Higher degrees of order are obtained upon formation of crystalline aggregates, or spheruHtes. The presence of a central crystallisation nucleus from which the lamellae radiate is clearly evident in these stmctures. Observations using cross-polarized light illustrates the characteristic Maltese cross model (Fig. 2b). The optical and mechanical properties ate a function of the size and number of spheruHtes and can be modified by nucleating agents. Crystallinity can also be inferred from thermal analysis (28) and density measurements (29). 

Nucleating agents and high polymeric impact modifier efficiency are judged by the modifications in optical (polarizing microscope) and mechanical properties. 

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