Light Microscopy

Experiment (2) Light Microscopy

Key Words

Generate your Abstract and line of thought using the following keywords:
Thermoplastic Polymers: morphology, solidification; Characterization : Polarization microscope, flame test ; Thermal properties: Polymer phase diagram: Crystalline vs. Amorphous, glass transition, melting point, degradation.

Introduction

Discuss the following topics in correct language and organized flow of ideas within your introduction:
1. Control of crystallinity and tactility of thermoplastics. Factors controlling crystallinity versus amorphism.
2. Effect of cooling rate, molecular orientation, functional groups and structural linearity.
3. Difference in solidification behavior (phase diagram) between amorphous and crystalline polymers.
4. Define: glass transition temperature

The introduction should be accompanied by an "Equipment" section, discussing Polarization Microscope:theory and components, as well as with a diagram for it.

The introduction should be followed with "Material" section, containing the following properties:
-Thermal properties of the selected polymer (T_g, T_m & degradation temperature/heat deflection)
-Repeated unit

Use Kalpakjian, Farag, Smith, lab handouts or other references (MatWeb)to generate the above information

Procedures

Explain the following points within your procedures section:
1. The concept of the experiment
2. Use the polarization microscope and flame test to identify the second material

Required Tests

1. Flammability test: for the unknown specimen along with the polarization microscope test

Results/Discussion Answer the following questions in the body of your discussion 1. Define: spheruletic, lamellar, and dendritic structure
2. Why is it impossible to obtain the same starting structure after fully melting and cooling backwards?
3. The result of flame test and the structure changes for the specimen
4. Trace the changes in microstructure at different temperatures while undergoing heating and then cooling

Further References/Images

--The following sites and books contain useful information and images for several articles that we have encountered in this experiment. Make sure to check them.

MatWeb

Kalpakjian, Serope. Manufacturing Process for Engineering Materials. Addison Wesley, 3^rd Ed., 1997.

Smith, William F. . Principles of Materials Science and Engineering. McGraw Hill, 3^rd Ed., 1996.

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