Major Plastics in Packaging: Polyolefins Family

These flashcards cover essential vocabulary and key concepts from the lecture on major plastics in packaging, focusing on polyolefins and their properties.

Polyolefins

A family of plastics based on ethylene and propylene, including linear and branched polyethylene and polypropylene.

LDPE

Low Density Polyethylene, a type of branched polyethylene known for its flexibility and clarity.

HDPE

High Density Polyethylene, a type of linear polyethylene known for its strength and barrier properties.

EVA

Ethylene Vinyl Acetate, a copolymer that enhances flexibility and clarity compared to LDPE.

EAA

Ethylene Acrylic Acid, a copolymer that increases adhesion and clarity and contains an acid group.

Metallocene

A type of polymer produced using metallocene catalysts resulting in polymers like Ultra Low Density PE (ULDPE) with improved properties.

Tacticity

The arrangement of substituent groups along a polymer chain, which can be isotactic, syndiotactic, or atactic.

Copolymers

Polymers made from two or more different monomers, which can enhance properties like flexibility and adhesion.

Polypropylene (PP)

A thermoplastic polymer made from propylene monomers with distinct properties and applications.

Ionomers

Copolymers neutralized with cations that exhibit improved adhesion and toughness.

Ziegler-Natta catalyst

A type of catalyst used in the production of linear polyethylene and polypropylene to control polymer structure.

Environmental stress cracking

Failure of a plastic when exposed to both stress and a chemical substance.

Linear PE vs. Branched PE

Linear PE has straight chains for higher density, while Branched PE has irregular chains leading to lower crystallinity.

Crystallinity

The degree to which a polymer has a well-ordered structure, influencing its mechanical properties.

Polyethylene

The first olefinic polymer used in food packaging, valued for its low cost and versatile applications.

Polymerization

The process of linking monomers to form a polymer, which can be initiated through various methods like free radical or catalytic processes.