CM8001

When Styrofoam is produced, hot air is blown into the polymer and to expand to 40 to 50 times the original size of the polymer. Therefore it contains a lot of air. When Styrofoam is dissolved in acetone, the air will be released and once the acetone is evaporated, the original polymer is left behind without the air.

A. Branched LDPE is not as strong as a material compared to linear HDPE.

B. It has a crystalline structure = higher density, stronger attraction force between molecules, overall stronger than LDPE. So the material will not break and you will not currently yourself.

No. Paper is made up of cellulose, a natural polymer, which is held together by strong hydrogen bonds. It has higher tensile strength and is less ductile/more brittle. Plastic bag is made up of LDPE and the long polymer chain has more allowance for shearing and the plastic stretches instead of breaking immediately.

A. Flexible, insolubility, non-toxic and inert

B. Hard – methyl methacrylate (PMMA)
Soft – hydroxylethyl methacrylate (polycrylamide)

Properties : transparent, flexible, low density, unreactice to chemicals on the surface, easy to manufacture, hydrophilic, permeable to Oxygen, tough.

C. Polycrylamide contains nitrogen atoms. Similarly to polymers to make acrylic fiber for fabrics. When Polycrylamide is cross-linked, the material absorbs water which keeps them less soft and flexible.