TABLE OF CONTENTS

Title Page    –         –         –         –         –         –         –         –         –         i

Certification –         –         –         –         –         –         –         –         –         ii

Dedication   –         –         –         –         –         –         –         –         –         iii

Acknowledgement –         –         –         –         –         –         –         –         iv

Table of Contents  –         –         –         –         –         –         –         –         v

CHAPTER ONE 

1.0 Brief History of Polyurethane Foam –         –         –         –         1

1.1 Theory of Polyurethane Foam Production         –         –         –         6

CHAPTER TWO

2.0 The chemistry of Polyurethane –         –         –         –         –         8

2.1 General Chemical Reactions          –         –         –         –         –         9

2.2 Blow Reaction           –         –         –         –         –         –         –         10

2.3 Gelation Reaction      –         –         –         –         –         –         –         11

2.4 Catalytic Reaction      –         –         –         –         –         –         –         12

2.5 Significance of various Chemicals, Elements and

Compounds used in Foam Production –         –         –         –         13

2.6 Types of Foam –         –         –         –         –         –         –         –         14

2.7 Flexible Foam  –         –         –         –         –         –         –         –         14

2.8 Rigid Foam      –         –         –         –         –         –         –         –         15

2.9 Rebound Foam –         –         –         –         –         –         –         –         15

2.10 Properties of Foam   –         –         –         –         –         –         –         16

2.11 Foam Production Process   –         –         –         –         –         –         17

CHAPTER THREE

3.0 Application of Polyurethane Foam – –         –         –         –         18

3.1 Appliance        –         –         –         –         –         –         –         –         19

3.2 Automobiles    –         –         –         –         –         –         –         –         19

3.3 Construction    –         –         –         –         –         –         –         –         19

3.4 Electronics       –         –         –         –         –         –         –         –         20

3.5 Furniture, Bedding and Seating      –         –         –         –         –         20

3.6 Coatings, Adhesives, Sealants and Elastomers (CASE)         –         20

3.7 Thermoplastic Polyurethane Application –         –         –         –         21

3.8 Reaction Injection Molding (RIM)          –         –         –         –         21

3.9 Binders  –         –         –         –         –         –         –         –         –         22

3.10 Composite Wood     –         –         –         –         –         –         –         23

3.11 Furnishings    –         –         –         –         –         –         –         –         23

3.12 Medical Applications         –         –         –         –         –         –         23

3.13 Packing Application –         –         –         –         –         –         –         24

3.14 Marine Application  –         –         –         –         –         –         –         24

CHAPTER FOUR

4.0 SUMMARY AND CONCLUSION

4.1 Summary         –         –         –         –         –         –         –         –         26

4.2 Conclusion       –         –         –         –         –         –         –         –         27

References

CHAPTER ONE

1.0 Brief History of Polyurethane Foam

The creation of foam started with the discovery of urethane chemicals. The scientists Wurtz and Hoffman were the first people to come across these chemicals. In 1849, they reported the first reaction between an isocyanate and a hydroxy compound, making the basis for foam development.

This information hibernated until 1937. In that year, while he was working at the laboratories of I.G. Farben industries A.G. in Leverkusen, Germany, Otto Bayer found the product that was birthed from the chemical reaction discovered by Wurtz and Hoffman. He started to see commercial uses for foam. The world was on the brink of World War II during this time, and essential products were scarce. This created a need to replace nylon, which Bayer intended to fill. To compete with nylon, Bayer began working on the creation of polyester-based urethane polymers, turning urethane into a product that could effectively be used commercially (Feske, 2004).

The onset of World War II stressed a heightened need for fibers, coatings, and foams, which Bayer’s work was able to fill. In 1942, the first patent for flexible polyurethane foam preparation was issued to Zaunbrecher and Barth. They created a one-step process for the production of foam, but it was highly exothermic, releasing a great deal of heat in the process. This meant that it typically resulted in scorched products and sometimes started fires. So, they ended up expanding the process to involve two steps instead, alleviating the factor of excessive heat being generated during production.

Once World War II had ended, German technology became known to the general global community. This sparked extensive research and development, especially in the United States, Germany, and Britain. Diisocyanates and polyester polyols were the common subject of study because they created foam. Unfortunately, the foam created by these elements yielded physical properties that we lackluster at best. Additionally, the process was expensive, and the foam product was excessively difficult to produce. So, scientists began looking for alternative hydroxy compounds that would be easier to make and would ultimately yield a better foam product (Goma et al., 2018).

In 1954, the first commercial production of foam began in Europe, followed shortly by the United States. Polyether polyols in the form of poly tetramethylene ether glycol (PTMEG) were introduced in 1956 by DuPont.

Then, in 1957 the world of foam and synthetic products went through a massive shift. A whole new range of more cost-effective polyether polyols came on the scene that vastly improved on the performance of existing polyester products. The process needed to create these foams allowed them to be more easily mass-produced, leading to a boom in production. The newer foams also had improved physical properties over existing options, making it more useful and popular. This time also brought about the introduction of silicone surfactants. Surfactants in foam production have a number of benefits, from reducing the work needed to create foam to making it more stable and helping to keep the “bubble” size more stable. These qualities improved the number of potential applications and the practicality of using foam. Because of these and other developments, the polyurethane industry saw an unprecedented boom.

During the 1960s, about 100 small companies competitively produced foam. While the manufacturing saw many improvements, shipping costs to the companies using the foam became an issue. The increased demand for high-quality foam led to the establishment of foam plants throughout the country so that they could be closer to their customers.

Today, over 725,000 tons of foam is produced every year in the United States alone, and it is an integral part of nearly every aspect of industry and production. Foam, and related products, are a huge part of consumer packaging. The research of foam and enhancing its physical properties wages on, creating a continuously evolving substance that only gets better.

Foam is commonly used in manufacturing mattresses, furniture, thermal insulation, acoustic products, car seats, and packaging materials, as well as numerous other mass-produced products that we frequently use. Out of all global polyurethane production, foams are about 67% of the total. In 2020, the estimated market of foam was about $37.8 billion, and it’s only expected to expand. By 2025, we should see growth landing the value of the foam industry at about $54.3 billion (Goma et al., 2018)

Foam has certainly seen many changes and developments over the years. It took a great deal of time to manifest, as well as countless hours of research to perfect the manufacturing process for foam. The physical properties of the foam we use today are leagues above the first product created, making it a staple for the creation of everyday products. Today it’s hard to imagine a world without foam, where your car seat or mattress wouldn’t be nearly as comfortable as it is now! So, every time you use your comfortable foam products, you can know that you’re using the product of a culmination of years of research, history, and development.

Starting in the early 1980s, water-blown micro cellular panels and air-filler seals, replacing PVC polymers, polyurethane foams are used in making automobile application including seating, head and arm rests and headliners.

Polyurethane 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 used of many chlorine containing blowing agents, such as trichlorofluoromethane. By the late 1990s, blowing agents such as carbon dioxide, Pentane, 1,1,1,2-tetrafluoroethane and 1,1,1,3,3,-pentafluoropropane were widely used in North America and the Eu, although Chlorinated blowing agents remained in use in many developing countries (Goma et al., 2018).

1.1 Theory of Polyurethane Foam Production

Polyurethane are linear polymers that have a molecular backbone containing carbornate groups (NHCO₂). The groups, called urethane are produced through a chemical reaction between a disocyanate and a Polyol. First developed in late 1930_s, Polyurethanes are some of the most versatile polymers. They are used in vast foam production, building insulation, surface coatings, adhesives, solid plastics, and athletic apparel.

Polyurethanes, also known as polycarbamates, belong to a larger class of compounds called polymers.

Polymers are macro molecules made up of smaller repeating unit known as monomers. Generally, they consist of a primary long-chain backbone molecule with attached side groups. Polyurethanes are characterized by Carbamate groups (-NHCO₂) in their molecular backbone. (Horrington, 1991).