PKG-323 Lecture #1 and #2: Polymer and Plastic Basics

What are the main functions of plastic packaging?

Plastic packaging protects, preserves, and transports goods, allows information display, and prevents spillage and waste.

What is primary packaging?

Packaging that is in direct contact with the product.

What is secondary packaging?

Packaging that groups primary packages together.

What is transportation packaging?

Packaging used for shipping and handling during transport.

What percentage of global primary plastic production was used for packaging in 2015?

Approximately 36%.

What is the most common packaging material in the U.S. by mass?

Paper and paperboard at about 51.2%.

Which material is the second most common packaging material in the U.S. by mass?

Plastics at about 18.8%.

What are the Big Three polymers used in packaging?

HDPE, PP, and PET.

What is a polymer?

A large macromolecule made of repeating monomer units bonded together.

What is a plastic?

A synthetic polymer that can be molded under heat and retains its shape when cooled.

What are natural polymers?

Polymers found in nature such as cellulose, proteins, and natural rubber.

What are synthetic polymers?

Man-made polymers produced through chemical processes.

What is a monomer?

A small repeating unit that links together to form a polymer.

What does degree of polymerization (DP) represent?

The number of repeating monomer units in a polymer chain.

What is IUPAC nomenclature?

A standardized system for naming chemicals based on structure.

What do the prefixes meth-, eth-, and prop- represent?

They indicate 1, 2, and 3 carbon atoms respectively.

What do the suffixes -ane, -ene, and -yne indicate?

Single, double, and triple carbon bonds respectively.

What are common polymer abbreviations used in packaging?

PE, PP, PS, and PVC.

What is a homopolymer?

A polymer made from only one type of monomer.

What is a copolymer?

A polymer made from two or more different monomers.

What are thermoplastics?

Plastics that can be melted and reshaped repeatedly.

What are thermosets?

Plastics that cannot be remelted once cured and will degrade when reheated.

What are commodity plastics?

Low-cost, high-volume plastics with moderate performance.

What are the Big Four commodity plastics?

PE, PP, PS, and PVC.

What are engineering plastics?

Plastics that maintain mechanical properties above 100°C.

What are specialty plastics?

High-performance, high-cost plastics used for specific applications.

What are primary bonds?

Bonds that hold atoms together within a molecule.

What is a covalent bond?

A bond formed by sharing electrons; the most common bond in plastics.

What is an ionic bond?

A bond formed by complete transfer of electrons; rare in plastics.

What are ionomers?

Plastics that contain ionic bonds, such as Surlyn.

What are secondary bonds?

Intermolecular forces that attract polymer chains to each other.

What is polarity in polymers?

The uneven distribution of electrons due to electronegativity differences.

What are non-polar polymers?

Polymers with equal electron sharing, such as PE and PP.

What are polar polymers?

Polymers with unequal electron sharing involving atoms like oxygen, nitrogen, chlorine, or fluorine.

What are the main advantages of plastics?

Low density, high strength-to-weight ratio, corrosion resistance, durability, and design flexibility.

What are major environmental challenges of plastics?

Non-renewable sourcing, landfill accumulation, and recycling difficulties.

What is permeation in packaging?

The movement of small molecules like gases or water vapor through the package.

What is sorption in packaging?

The absorption of product components into the packaging material.

What is migration in packaging?

The transfer of small molecules from the packaging into the product.

What are functional groups in polymers?

Reactive chemical units that affect polymer synthesis, performance, and degradation.

What is the alcohol functional group?

A functional group containing -OH that influences polymer behavior.

What is the amide functional group?

A functional group containing CNO that affects strength and degradation.