POLYURETHANE-28

Polyurethane-28 helps form a smooth and flexible film that improves product hold and surface protection.
Polyurethane-28 is useful in cosmetic and coating formulations where water resistance, durability, and adhesion are needed.
Polyurethane-28 supports long-lasting performance in hair styling, makeup, skin care, nail, textile, and industrial products.

Synonyms: Polyurethane-28, PU-28, Polyurethane 28, Polyurethane Polymer, Polyurethane Film Former, Polyurethane Binder, PU Film Former, Synthetic Polyurethane Polymer, Polyurethane Resin, Polyurethane Dispersion, Waterborne Polyurethane Polymer, Polyurethane Coating Polymer, Film-Forming Polyurethane, Cosmetic Polyurethane Polymer, INCI Polyurethane-28

Polyurethane-28 is a synthetic Polyurethane polymer commonly used as a film-forming agent, binder, and conditioning polymer in cosmetic, personal care, coating, and industrial formulations.
Polyurethane-28 helps create a flexible, smooth, and durable film on the surface of skin, hair, textiles, or coated materials.
Polyurethane-28 is especially valued for its good adhesion, flexibility, water resistance, abrasion resistance, and improved surface feel.

Polyurethane-28 often abbreviated as PUR and PU) is a class of polymers composed of organic units joined by carbamate (urethane) links.
In contrast to other common polymers such as polyethylene and polystyrene, Polyurethane-28 refers to a group of polymers.

Unlike polyethylene and polystyrene, Polyurethane-28's can be produced from a wide range of starting materials, resulting in various polymers within the same group.
Polyurethane-28 variety produces Polyurethane-28's with different chemical structures leading to many different applications.

These include rigid and flexible foams, and coatings, adhesives, electrical potting compounds, and fibers such as spandex and Polyurethane-28 laminate (PUL).
Foams are the largest application accounting for 67% of all Polyurethane-28 produced in 2016.

A Polyurethane-28 is typically produced by reacting a diisocyanate (or a polymeric isocyanate) with a polyol.
Since a Polyurethane-28 contains two types of monomers, which polymerize one after the other, they are classed as alternating copolymers.
Both the isocyanates and polyols used to make a Polyurethane-28 contain two or more functional groups per molecule.

Global production in 2019 was 25 million metric tonnes accounting for about 6% of all polymers produced in that year.

Uses of Polyurethane-28:
Polyurethane-28 is used as a film-forming agent, binder, and surface-conditioning polymer in cosmetic, personal care, coating, and industrial formulations.
Polyurethane-28 is commonly used in hair styling gels, hair sprays, mascaras, eyeliners, sunscreens, skin care products, nail products, textile coatings, inks, adhesives, and protective coatings.
Polyurethane-28 helps improve flexibility, adhesion, water resistance, durability, smoothness, and long-lasting performance in the final product.

Chemistry of Polyurethane-28:
Polyurethane-28's are produced by reacting diisocyanates with polyols often in the presence of a catalyst, or upon exposure to ultraviolet radiation.
Common catalysts include tertiary amines, such as DABCO, DMDEE, or metallic soaps, such as dibutyltin dilaurate.

The stoichiometry of the starting materials must be carefully controlled as excess isocyanate can trimerise, leading to the formation of rigid polyisocyanurates.
Polyurethane-28 usually has a highly crosslinked molecular structure, resulting in a thermosetting material which does not melt on heating; although some thermoplastic Polyurethane-28's are also produced.

The most common application of Polyurethane-28 is as solid foams, which requires the presence of a gas, or blowing agent, during the polymerization step.
This is commonly achieved by adding small amounts of water, which reacts with isocyanates to form CO2 gas and an amine, via an unstable carbamic acid group.

The amine produced can also react with isocyanates to form urea groups, and as such the polymer will contain both these and urethane linkers.
The urea is not very soluble in the reaction mixture and tends to form separate "hard segment" phases consisting mostly of polyurea.
The concentration and organization of these polyurea phases can have a significant impact on the properties of the foam.

The type of foam produced can be controlled by regulating the amount of blowing agent and also by the addition of various surfactants which change the rheology of the polymerising mixture.
Foams can be either "closed-cell", where most of the original bubbles or cells remain intact, or "open-cell", where the bubbles have broken but the edges of the bubbles are stiff enough to retain their shape, in extreme cases reticulated foams can be formed.

Open-cell foams feel soft and allow air to flow through, so they are comfortable when used in seat cushions or mattresses.
Closed-cell foams are used as rigid thermal insulation.

High-density microcellular foams can be formed without the addition of blowing agents by mechanically frothing the polyol prior to use.
These are tough elastomeric materials used in covering car steering wheels or shoe soles.

The properties of a Polyurethane-28 are greatly influenced by the types of isocyanates and polyols used to make it.
Long, flexible segments, contributed by the polyol, give soft, elastic polymer.

High amounts of crosslinking give tough or rigid polymers.
Long chains and low crosslinking give a polymer that is very stretchy, short chains with many crosslinks produce a hard polymer while long chains and intermediate crosslinking give a polymer useful for making foam.
The choices available for the isocyanates and polyols, in addition to other additives and processing conditions allow Polyurethane-28's to have the very wide range of properties that make them such widely used polymers.

History of Polyurethane-28:
Otto Bayer and his coworkers at IG Farben in Leverkusen, Germany, first made Polyurethane-28's in 1937.
The new polymers had some advantages over existing plastics that were made by polymerizing olefins or by polycondensation, and were not covered by patents obtained by Wallace Carothers on polyesters.

Early work focused on the production of fibers and flexible foams and PUs were applied on a limited scale as aircraft coating during World War II.
Polyisocyanates became commercially available in 1952, and production of flexible Polyurethane-28 foam began in 1954 by combining toluene diisocyanate (TDI) and polyester polyols.

These materials were also used to produce rigid foams, gum rubber, and elastomers.
Linear fibers were produced from hexamethylene diisocyanate (HDI) and 1,4-butanediol (BDO).

DuPont introduced polyethers, specifically poly(tetramethylene ether) glycol, in 1956.
BASF and Dow Chemical introduced polyalkylene glycols in 1957.

Polyether polyols were cheaper, easier to handle and more water-resistant than polyester polyols.
Union Carbide and Mobay, a U.S. Monsanto/Bayer joint venture, also began making Polyurethane-28 chemicals.

In 1960 more than 45,000 metric tons of flexible Polyurethane-28 foams were produced.
The availability of chlorofluoroalkane blowing agents, inexpensive polyether polyols, and methylene diphenyl diisocyanate (MDI) allowed Polyurethane-28 rigid foams to be used as high-performance insulation materials.

In 1967, urethane-modified polyisocyanurate rigid foams were introduced, offering even better thermal stability and flammability resistance.
During the 1960s, automotive interior safety components, such as instrument and door panels, were produced by back-filling thermoplastic skins with semi-rigid foam.

In 1969, Bayer exhibited an all-plastic car in Düsseldorf, Germany.
Parts of this car, such as the fascia and body panels, were manufactured using a new process called reaction injection molding (RIM), in which the reactants were mixed and then injected into a mold.

The addition of fillers, such as milled glass, mica, and processed mineral fibers, gave rise to reinforced RIM (RRIM), which provided improvements in flexural modulus (stiffness), reduction in coefficient of thermal expansion and better thermal stability.
This technology was used to make the first plastic-body automobile in the United States, the Pontiac Fiero, in 1983.
Further increases in stiffness were obtained by incorporating pre-placed glass mats into the RIM mold cavity, also known broadly as resin injection molding, or structural RIM.

Starting in the early 1980s, water-blown microcellular flexible foams were used to mold gaskets for automotive panels and air-filter seals, replacing PVC polymers.
Polyurethane-28 foams are used in many automotive applications including seating, head and arm rests, and headliners.

Polyurethane-28 foam (including foam rubber) is sometimes made using small amounts of blowing agents to give less dense foam, better cushioning/energy absorption or thermal insulation.
In the early 1990s, because of their impact on ozone depletion, the Montreal Protocol restricted the use of many chlorine-containing blowing agents, such as trichlorofluoromethane (CFC-11).

By the late 1990s, blowing agents such as carbon dioxide, pentane, 1,1,1,2-tetrafluoroethane (HFC-134a) and 1,1,1,3,3-pentafluoropropane (HFC-245fa) were widely used in North America and the EU, although chlorinated blowing agents remained in use in many developing countries.
Later, HFC-134a was also banned due to high ODP and GWP readings, and HFC-141B was introduced in early 2000s as an alternate blowing agent in developing nations.

Stability and Reactivity of Polyurethane-28:

Chemical stability:
Polyurethane-28 is stable under recommended storage and handling conditions.

Reactivity:
No dangerous reaction is expected under normal conditions of use.
Some grades may be sensitive to strong oxidizing agents, strong acids, strong bases, or reactive chemicals depending on formulation.

Conditions to avoid:
Avoid excessive heat, open flames, sparks, direct sunlight, freezing, moisture, dust formation, and contamination.

Incompatible materials:
Strong oxidizing agents, strong acids, strong bases, and reactive chemicals.

Hazardous decomposition products:
Thermal decomposition or combustion may produce carbon monoxide, carbon dioxide, nitrogen oxides, hydrogen cyanide, isocyanate vapors, smoke, and irritating or toxic fumes.

Handling and Storage of Polyurethane-28:

Handling:
Handle in accordance with good industrial hygiene and safety practices.
Avoid contact with eyes, skin, and clothing.
Avoid breathing dust, mist, vapors, aerosols, or fumes generated during heating or processing.

Storage:
Store in a cool, dry, and well-ventilated area.
Keep container tightly closed when not in use.

Storage conditions:
Protect from heat, direct sunlight, freezing, moisture, ignition sources, and contamination.
Store away from incompatible materials.

Packaging materials:
Keep in original sealed drums, pails, bottles, bags, IBC containers, or suitable industrial packaging.

Shelf life:
Stable under recommended dry and sealed storage conditions.

First Aid Measures of Polyurethane-28:

Inhalation:
Move person to fresh air.
If coughing, irritation, dizziness, or breathing difficulty occurs, seek medical attention.

Skin contact:
Wash affected area with soap and plenty of water.
Remove contaminated clothing if necessary.
If irritation persists, seek medical attention.

Eye contact:
Rinse cautiously with clean water for several minutes.
Remove contact lenses if present and easy to do.
Continue rinsing and seek medical attention if irritation persists.

Ingestion:
Rinse mouth with water.
Do not induce vomiting unless instructed by medical personnel.
Seek medical attention if discomfort occurs.

Most important symptoms:
May cause mild irritation to eyes, skin, or respiratory tract.
Heated material, vapors, aerosols, or decomposition fumes may cause stronger respiratory irritation.

Firefighting Measures of Polyurethane-28:

Suitable extinguishing media:
Use water spray, foam, dry chemical powder, or carbon dioxide.

Unsuitable extinguishing media:
Do not use a direct high-pressure water jet, as it may spread burning material or liquid resin.

Specific hazards:
Product may burn under fire conditions.
Combustion or thermal decomposition may produce carbon monoxide, carbon dioxide, nitrogen oxides, hydrogen cyanide, isocyanate vapors, dense smoke, and irritating or toxic fumes.

Protective equipment for firefighters:
Firefighters should wear self-contained breathing apparatus and full protective clothing.

Firefighting instructions:
Cool exposed containers with water spray.
Avoid inhalation of smoke and decomposition gases.
Prevent contaminated firefighting water from entering drains or waterways.

Accidental Release Measures of Polyurethane-28:

Personal precautions:
Avoid contact with eyes, skin, and clothing.
Avoid breathing dust, mist, vapors, aerosols, or fumes.

Spilled material may create a slipping hazard.
Use appropriate personal protective equipment.

Environmental precautions:
Prevent material from entering drains, soil, surface water, or waterways.

Methods for containment:
Stop the leak or spill if safe to do so.
Contain liquid material with inert absorbent material, or collect solid material mechanically.

Methods for cleaning up:
Absorb liquid material with sand, earth, vermiculite, or other inert absorbent.
Sweep, shovel, or vacuum solid material using dust-control methods.
Place into suitable labeled containers for disposal.

Disposal:
Dispose of collected material according to local, regional, and national regulations.

Exposure Controls / Personal Protective of Polyurethane-28:

Engineering controls:
Use adequate ventilation during handling.
Provide local exhaust ventilation where dust, mist, aerosols, solvent vapors, or processing fumes may be generated.

Respiratory protection:
Normally not required under standard handling conditions.
Use suitable respiratory protection if ventilation is insufficient or if dust, vapor, aerosol, or fumes are generated.

Hand protection:
Wear protective gloves suitable for chemical handling.
Heat-resistant gloves are required when handling hot or molten material.

Eye protection:
Wear safety glasses or chemical splash goggles.
Use face protection where splashing, hot material, or processing fumes may occur.

Skin and body protection:
Wear suitable protective clothing to prevent prolonged or repeated contact.
Use protective workwear during processing or hot handling.

Hygiene measures:
Wash hands after handling and before eating, drinking, or smoking.
Remove contaminated clothing and wash before reuse.
Keep away from food, beverages, and animal feed.

Identifiers of Polyurethane-28:
Name: Polyurethane-28
Category: Beauty and Personal Care
Chemical Name: Polyurethane-28
INCI Name: Polyurethane-28
CosIng Ref No: 87579

Properties of Polyurethane-28:
Appearance: Liquid dispersion, viscous liquid, resin, or solid depending on grade
Color: Clear, white, milky, yellowish, or amber depending on formulation
Odor: Mild characteristic odor