Polymer

Polymer

Long molecules formed by connecting monomers with covalent bonds.

Polymerization

Process of forming polymers by connecting monomers.

Macromolecules

Large molecules like proteins, not all are polymers.

Molecular Weight

Sum of molar masses of all elements in a molecule.

Molar Mass

Mass in grams of one mole of an element.

Polyethylene

Polymer formed by multiple ethylene molecules.

Molecular Weight Distribution

Variation in molecular weights of synthetic polymers.

Chain Growth Polymerization

Process for monomers with vinyl groups like ethylene.

Step-Growth Polymerization

Involves reaction of bi-functional monomers like polyesters.

Degree of Polymerization

Number of repeat units in a polymer molecule.

Free Radical Polymerization

Initiation, propagation, and termination steps in ethylene polymerization.

Polymer Chains

Grow statistically, leading to a distribution of chain lengths.

Polyesters

Formed by reaction of diol and diacid in step-growth polymerization.

Polyamides

Formed by reaction of diamine and diacid in step-growth polymerization.

Polycarbonates

Formed by reaction of dihydroxy compound and phosgene.

Polyolefins

Chain-growth polymers like polyethylene and polypropylene.

Polystyrene

A chain-growth polymer used in various applications.

Polyisoprene

A natural rubber polymer with unique properties.

Polymer Chains Growth

Sequential statistical steps lead to varied chain lengths.

Melt Flow Index

Measure of polymer flow rate related to molecular weight.

Vinyl Group

Functional group with formula -HC=CH2 in chain-growth polymerization.

Chain Length Distribution

Variation in chain lengths of polymer chains.

Redox Systems

Systems like H2O2 + Fe2+ that generate radicals for polymerization.

Termination reactions

Absence of reactions leading to chain growth stoppage

Chain transfer agents

Substances causing chain growth cessation in polymerization

Random coils

Common state of polymers, not as extended chains

Polymer chain length

Distance between repeat units in a polymer chain

Linear polymers

Polymers with unbranched structures

Branched polymers

Polymers with side chains of similar dimensions to the backbone

Step-growth polymerization

Polymerization via multifunctional monomers

Chain-growth polymerization

Polymerization involving transfer to polymer reactions

Grafting reactions

Processes forming branches in polymer chains

Homopolymers

Polymers with a single repeat unit type

Copolymers

Polymers with two or more repeat unit types

Thermoplastics

Polymers that can be melted and solidified repeatedly

Elastomers

Rubber-like polymers with elastic and viscous properties

Plastomers

Polymers combining plastic and elastomer characteristics

Thermosets

Polymers with 3D networks and strong covalent bonds

Stress-Strain Curves

Graphs showing material response to stress

Creep and Stress Relaxation

Material responses to constant stress or deformation

Molecular Weight Averages

Various averages describing polymer chain sizes

Polydispersity Index

Measure of polymer MWD broadness

Viscosity-average molecular weight

Molecular weight average based on polymer viscosity

Chain Length Averages

Averages describing the length of polymer chains

Weight Average Molecular Weight (Mw)

Average molecular weight considering weight fraction of each molecule

Number Average Molecular Weight (Mn)

Average molecular weight considering number of molecules

Weight Average Chain Length (Nw)

Average chain length considering weight fraction of each chain

Number Average Chain Length (Nn)

Average chain length considering number of chains

Đ (Đelta)

Polydispersity index, a measure of molecular weight distribution

Standard Deviation (s)

Measure of dispersion around the mean in a dataset

Melt Flow Index (MFI)

Measure of a polymer's flowability at a specified temperature and load

Crystallinity

Degree of molecular order in a polymer, affecting properties

Spherulites

Spherical structures in polymers formed during crystallization

Bimodal Polyethylene

Polyethylene with two distinct molecular weight distributions

Catalysis

Process of increasing the rate of a chemical reaction using a catalyst

Kinetics

Study of rates of chemical processes

Reactor Engineering

Design and operation of reactors for chemical processes

Intrarparticle Mass Transfer

Movement of mass within a particle

Heat Transfer Phenomena

Transfer of thermal energy between objects

Stereo- and Regioregularity

Arrangement of atoms in space and along a polymer chain

Long Chain Branch Distribution

Variability in the presence of long chain branches in a polymer

Microstructure

Arrangement of molecules in a polymer, affecting properties

Stockmayer Distribution

Distribution of molecular weights in a polymer sample

Polyethylene Resins

Commercial forms of polyethylene with varying densities

Transition Metal Catalysts

Catalysts used in coordination polymerization reactions

Metallocene Catalysts

A type of transition metal catalyst used in polymerization

Ziegler-Natta Catalysts

Heterogeneous catalysts used in olefin polymerization

Phillips Catalysts

Catalysts used in the polymerization of olefins

Homogeneous

Polymerization in a single phase (e.g., bulk, solution)

Heterogeneous

Polymerization in multiple phases (e.g., suspension, emulsion)

Bulk Polymerization

Simple process with monomer and catalyst, high viscosity at high conversions

Solution Polymerization

Uses a solvent to control viscosity, easier temperature control, solvent separation needed

Suspension Polymerization

Monomer suspended in water, prevents coalescing, requires post-polymerization steps

Plastics

Economical material with low processing temperatures and densities suitable for light-weight applications.

Compounding

Mixing polymers with additives to modify material properties.

PE, PP, PVC, PET, PS, PUR

Common polymers used in plastics manufacturing.

Banbury Mixer

Internal batch mixer for plastics compounding with complex shearing flows.

Twin-Screw Extruder

Continuous mixing device for plastics compounding with melting and intensive mixing.

Pelletizing

Transforming molten plastic blends into small solid pellets for various applications.

Plastics Processing

Techniques to convert raw plastic materials into finished products for everyday use.

Extrusion

Process using single-screw extruders to produce pipes, sheets, profiles, and filaments.

Screw Diameter, L/D Ratio

Geometric parameters controlling extruder output rate and power demand.

Feed, Transition, Metering Zone

Different zones in extruder screw and barrel for material conveyance, preheating, and pressure buildup.

Extrusion Dies

Tools used to shape plastic melts into desired profiles

Annular Orifice

Die shape for producing pipes and hoses

Slit Die

Die shape for producing sheets and films

Coextrusion

Process where multiple polymer materials merge before solidifying

Multilayer Packaging Films

Products made by coextrusion for strength and gas permeability

Extrusion Film Blowing

Process using an annular die to create tubular products

Blown Film Machine

Equipment for extruding thin-walled tubes and flat films

Injection Molding

Common technique for manufacturing end products from thermoplastics

Plastification

Process of melting and homogenizing raw plastic material

Injection Molding Mold

Complex tool for shaping molten plastic into desired products

Extrusion Blow Molding

Method for producing hollow articles like bottles

Injection Blow Molding

Process where preforms are molded and then blown into final shape

Stretch Blow Molding

Technique using bi-axial stretching to strengthen containers

Rotational Molding

Process for making large hollow objects with smooth outer surfaces