polymers

Polymer

A large molecule made up of repeating structural units known as monomers, typically connected by covalent chemical bonds.

What distinguishes polymers from small molecules?

Polymers are large molecules formed by joining together many smaller units (monomers), while small molecules are individual chemical entities and not part of a larger structure.

Addition Polymerization

A process by which monomers react to form a polymer without the loss of any small molecules, often involving the opening of double bonds.

Crystalline regions

Structured areas within a polymer where the molecular chains are closely packed and ordered, contributing to the material's strength and stiffness.

Amorphous regions

Disordered areas in a polymer where molecular chains are entangled without a defined arrangement, leading to flexibility and reduced strength.

Thermoplastics

A type of plastic polymer that becomes pliable or moldable upon heating and solidifies upon cooling, allowing for recycling.

What is a typical characteristic of amorphous polymers?

Amorphous polymers do not have a well-defined structure and have a random orientation of chains, which contributes to their flexibility.

Hydrophobic

Substances that do not have an affinity for water; they repel water and do not dissolve in it.

Bio-degradable polymers

Polymers that can be broken down by natural processes, typically involving microorganisms, into harmless products.

What advantages do drug-eluting implants offer?

They provide a sustained and controlled release of medication over time, reducing the need for frequent administration.

Osmotic device

A type of drug delivery system that uses osmotic pressure to release medication at a controlled rate.

What are the key factors that influence the properties of a polymer?

Factors include the chemical composition, molecular weight, crystalline vs. amorphous structure, and the presence of additives or modifiers.

Elastomers

A category of polymers that exhibit elastic properties, allowing them to stretch and then return to their original shape.

What role do plasticizers play in polymers?

Plasticizers are added to polymers to increase flexibility and workability by reducing intermolecular forces between chains.

What is the difference between pendant and in-chain drug conjugates?

Pendant drug conjugates have drugs attached to the polymer backbone, while in-chain drug conjugates incorporate drugs within the polymer structure itself.

What is sustained-release drug delivery?

A method of administering medication in a way that allows for a controlled release over an extended period, maintaining therapeutic levels.

Cross-linking

A process that connects polymer chains together, enhancing the strength and stability of the material but can reduce flexibility.

What is chemical control release in drug delivery?

A system where the release of the drug occurs through the chemical breakdown of the polymer matrix.

Hydrogels

Water-swollen, cross-linked polymer networks that can absorb significant amounts of water while retaining their structure.

Biocompatibility

The ability of a material to perform its desired function without eliciting an adverse immune response in the body.

Kinetics of drug release

The study of the rates and mechanisms by which drugs are released from their carrier systems into the surrounding environment.

What are the benefits of using natural polymers?

Natural polymers are often biodegradable, biocompatible, and can be derived from renewable resources.

Amorphous vs. crystalline polymers

Amorphous polymers lack a definite structure leading to flexibility, while crystalline polymers have ordered structures that provide strength.