Plastics, an introduction

Mention the two parts that make up a plastic

• monomer and fillers

• monomer and pigments

• polymer and additives

• pigments and fillers

The melt temperature (T_m) in a semicrystalline polymer is lower than its glass transition (T_g).

• True

• False

Elastomers are characterized by all these properties EXCEPT one, identify it:

• Very low density

• Abrasion and wear resistance

• They are recyclable

• Thermal insulator

What does the thermal expansion coefficient measure?

• the changes of length by degree per temperature

• the changes of proportionality per Kelvin grade

• the changes of proportionality per degree of temperature

Amorphous thermoplastic polymers tend to have greater chemical resistance than semicrystalline.

• True

• False

Polymers are good ________________ and __________________ insulators.

(a)  

Identify the polymer with recycling code number 4

• LDPE

• HDPE

• PP

• PET

Stabilizers are used to inhibit the degradation mechanisms in polymer processing:

• True

• False

This material can be found in imitation leather, flooring, and inflatable products.

• Polypropylene

• Acrylic

• flexible PVC

• Polyester

what kind of chemical bonds are found in thermoplastics?

• just covalent bondings

• just ionic bondings

• just Van der Waals

• Covalent bondings and Van der Waals

• Covalent and ionic bondings