Polymer Chemistry

Demo A Day IV

Dean Campbell uses demonstrations and props to illustrate concepts while teaching his collegiate Materials Chemistry course. Many of the examples described are also suitable for use in high school and collegiate General Chemistry courses. 

Laser-Cutting CDs into Snowflakes

Laser cutters can be used to cut and engrave a variety of thin materials. Compact discs, composed of layers of polycarbonate plastic and aluminum metal, were explored for their ability to be shaped with a laser cutter. The laser can successfully cut and engrave the compact discs into the shape of snowflake. However, each disc must first be coated with a material like glue in order to protect the plastic from discoloration and the byproducts from cutting the plastic that can accumulate on the disc surface.  

A Visit to Natural Fiber Welding: Demonstrating Green Chemistry in Action

The theme to the 2022 National Chemistry Week, observed October 16-22, is “Fabulous Fibers: The Chemistry of Fabrics”. A visit to Natural Fiber Welding, Inc. in Peoria, IL, revealed how that company is using ionic liquids to solvent weld cellulose fibers together to produce more durable yarn which can then be made into more durable fabric. The production method and “greenness” of the product is discussed, from the cellulose itself to the recycling of the solution used in the welding process. Macroscopic demonstrations of the fiber solvent welding process are also described. 

A Polystyrene Model of Polystyrene Tacticity

Thin sheets of polystyrene can be patterned with permanent markers to represent repeating units of the polymer and then shrunk down in size using heat. The shrunken models of the repeating units can be connected with a string and then flipped into positions to demonstrate different types of polymer tacticity.

Microplastics, Liquid Nitrogen, and Iodine: Polystyrene vs. Starch Foam Packing Peanuts

The differing electrostatic and solubility properties of starch and polystyrene foam packing peanuts are used in various demonstrations to describe aspects of microplastics and their interactions with the environment. Their differing responses to exposure to liquid nitrogen and iodine solutions are also described.

Surveying Litter as a Citizen Science Chemistry Activity

During the last few semesters, a small survey has been deployed at Bradley University where students were to describe and classify items of litter that they found. The purposes of the surveys were to get students thinking about some of the chemical implications of solid waste and give the students some experience with a citizen science project. The most recent iteration of the survey, and some of its results, are described.