Polarized light microscopy spherulites

Light microscopy has been used in a number of contexts to characterize block copolymer morphology. For crystalline block copolymers, spherulitic structures that result from organization of crystalline lamellae can be examined using microscopy. In solutions, polarized light microscopy can reveal the presence of lamellar and hexagonal-packed cylindrical micellar phases. Cubic micellar phases are optically isotropic, and consequently cannot be distinguished from sols only on the basis of microscopy. 

Figure 10a shows the view under polarized light microscopy where the polarizer and analyzer axes are vertical and horizontal. The volume-filling spherulites with an... 

Presence of TCL changes the properties of crystalline matrix. Transcrystallization of isotactic polypropylene in the presence of different fibers has been thoroughly analyzed. Gray as the first one provided detailed description of isotactic polypropylene behavior in the presence of wood fibers using polarized light microscopy. He observed that when melted polymer is cooled down, it crystallizes in spherulite forms in nonisothermal and isothermal conditions, creating additionally a TCL. 

A wide range of microscopy techniques are applied to the characterization of engineering resins and plastics. For example, crystalline polymers are viewed by polarized light microscopy to reveal the size and distribution of spherulites and the nature of the local orientation. Surface details, such as wear and abrasion are best viewed by SEM. For example, Vaziri et al. 

Waddon et al [315] have extensively studied the crystal texture of PEEK, PEK and PPS, including melt grown spherulites using polarized light microscopy. They formed thin films by heating the polymer and the fibers on microscope slides and pressing them or smearing between the slides and coverslips. Polymers were chosen... 

Negative and positive spherulites are readily distinguished by polarized light microscopy. How Also explain the differences in morphology between the two. 

Most of the kinetic work has dealt with the temperature dependence of the growth rate in accordance with the kinetic theory of Lauritzen and Hoffman (see Hoffman et al. 1975). The experimental data, the linear growth rate (G) of spherulites (axialites), are obtained by hot-stage polarized light microscopy at different constant temperatures and the data are adapted to the equation ... 

Polarizing light microscopy employs crossed polarizers to view the sample. With isotropic specimens, the field of view is dark, while anisotropic, birefringent samples or areas of a sample will appear bright. Polarizing microscopy is employed to view spherulitic structure [66-68] and deformation morphologies (crazes, shear banding) [69] in polymer blends. Samples for... 

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