Lecture 7 (BME 296)

Crystallinity

The degree of structural order in a polymeric material.

Tacticity

The arrangement of side groups on the polymer chain; includes isotactic, syndiotactic, and atactic.

Isotactic

A polymer configuration where the side groups are oriented in the same direction.

Syndiotactic

A polymer configuration where the side groups alternate orientation along the main chain.

Atactic

A polymer configuration where the side groups are arranged randomly along the chain.

Melting Temperature (Tm)

The temperature above which a crystalline material becomes a liquid.

Glass Transition Temperature (Tg)

The temperature below which an amorphous material behaves like a glass (solid).

Crystallization Temperature (Tc)

The temperature at which a previously amorphous polymer begins to crystallize.

Copolymers

Polymers made from two or more different types of monomers.

Amorphous polymers

Polymers that lack a distinct crystalline structure.

Thermal Transition

The process in which a material changes its phase or properties due to temperature changes.

Differential Scanning Calorimetry (DSC)

A thermal analysis technique used to measure the heat flow associated with phase transitions in materials.

Semicrystalline

Polymers that contain both crystalline and amorphous regions.

Molecular Weight

A measure of the mass of one molecule of a substance, often affecting the properties of polymers.

Intermolecular forces

Attractive forces between molecules that influence material properties such as Tg.

Kinetic Energy

The energy that a body possesses by virtue of being in motion, which increases with temperature.

Bulky Side Groups

Large substituents attached to a polymer chain that reduce flexibility and crystallinity.

Chain Flexibility

The ease with which the polymer chains can rotate and move, impacting properties like Tg.

Thermal Phase Transition

The change of a material's phase due to added or removed thermal energy.

Exothermic Process

A process that releases heat, such as the crystallization of polymers.

Viscous Flow

The flow behavior of a liquid, characterized by resistance to deformation.

Polymeric Biomaterials

Synthetic or natural polymers used in medical applications.

Gene Expression

The process by which information from a gene is used to synthesize a functional gene product, often influenced by material properties.

Entanglement

The physical intertwining of polymer chains which restricts their movement.

Collagen Scaffolds

Biomaterials designed to support tissue engineering and regenerative medicine.