Plastic is one of the synthetic materials that you frequently encounter in housewares, such as food containers, baskets, trash bags, and many more.  Not only that, but plastic is also used to produce automotive components, food packages, medical tools, and so on.  But, did you know what plastic is made of? This article of TLD Vietnam discusses the plastic raw materials and the manufacturing process. So, read the information until the end!

Historical Background

The origins of plastic trace back to the 19th century, when early synthetic materials were developed as substitutes for natural resources like ivory, shellac, or horn. The true milestone came in the early 20th century with the invention of Bakelite, widely regarded as the first fully synthetic plastic. Its introduction marked a turning point in material science, laying the foundation for the modern polymer industry and the development of countless plastic-based innovations that followed.

Plastics and Their Classification

Global plastic production has continued to rise steadily over the decades, reflecting its indispensable role across multiple industries such as packaging, construction, automotive, and consumer goods. The sustained growth of plastic manufacturing highlights its versatility, cost efficiency, and adaptability to diverse applications.

Plastics are broadly categorized into three main groups based on their thermal behavior and molecular structure: thermoplastics, elastomers, and thermosetting polymers.

Thermoplastics are polymers that soften when heated and solidify upon cooling, allowing them to be remolded multiple times without significant degradation. Common examples include polyethylene (PE), polypropylene (PP), and polyvinyl chloride (PVC).

Elastomers are polymers with high elasticity, capable of being stretched and returning to their original shape, much like natural rubber. Materials such as silicone and polyurethane (PU) belong to this category.

Thermosetting polymers, by contrast, undergo a permanent chemical cross-linking reaction during curing. Once hardened, they cannot be reshaped or melted again. Examples include epoxy resin, phenolic resin, and Bakelite.

What Is Plastic Made Of? 

If you are wondering what plastic is made of, the water-resistant and anti-corrosion product is made of chemical structures, such as hydrogen, carbon, oxygen, and so on. Then, the raw materials are petroleum and natural gas. Below are the plastic raw materials you should know:

Petroleum

Plastics are primarily produced from petrochemicals, which are chemical compounds obtained from petroleum and natural gas. These hydrocarbons serve as the essential raw materials that determine the structure and properties of different plastics.

During petroleum refining, one key intermediate product – naphtha- is generated and used extensively in plastic manufacturing. Through a process called steam cracking, naphtha is decomposed into smaller hydrocarbon molecules known as olefins, mainly ethylene, propylene, and butadiene. In addition, this process yields aromatic compounds such as benzene, toluene, and xylene.

The olefins and aromatics obtained from cracking act as monomers, which then undergo polymerization to form long molecular chains known as polymers. These polymers are subsequently processed through various conversion methods, such as extrusion, molding, or compounding, to produce the wide range of plastic materials used across industries today.

Cellulose

Cellulose is a naturally occurring substance found in plant cell walls and serves as an important renewable resource for producing bioplastics. During processing, cellulose can be broken down into monomers for polymer synthesis or chemically modified through specific reactions to form plastic materials directly.

Natural Gas

Natural gas and crude oil act as the principal raw materials for plastic manufacturing. Through advanced refining and cracking processes, these fossil resources are decomposed into fundamental chemical compounds such as ethylene and propylene, which serve as key monomers for producing various kinds of synthetic plastics.

How Plastic Is Made

Most plastic production undergoes extraction, refining, polymerization, and mixing with other materials. Below is the process of plastic making.

Extraction

The first process is raw material extraction, such as petroleum and natural gas. Then, it will proceed to the next steps.

Gas (and crude oil) extraction is itself a major source of carbon emissions, from the deforestation that occurs while clearing land to make room for drilling equipment to the methane emitted via flaring and leaking during the fracking process itself, a greenhouse gas 20 times more potent than carbon dioxide

Refining

Petroleum will be refined to become various petroleum products. The crude oil will be heated in a furnace and sent to a distillation unit to separate the lighter components. One of the components used to produce plastic mass is naphtha.

Polymerization

Polymerization is the chemical process that converts small reactive molecules, known as monomers, into long molecular chains called polymers.

Monomers, typically derived from petrochemical feedstocks such as naphtha or natural gas, act as the building blocks of polymers. Their chemical structure and the way they link together determine the resulting polymer’s characteristics, including its strength, flexibility, and thermal stability. Variations in monomer type and polymer chain configuration give rise to the wide diversity of plastics used across industries—from everyday packaging materials to engineering-grade polymers.

This transformation is fundamental to plastic production, as it determines the material’s structure and physical properties. The process can occur through two main mechanisms: addition polymerization and condensation polymerization.

In addition polymerization, unsaturated monomers such as ethylene and propylene combine through a chain-growth reaction, often initiated by catalysts or free radical initiators (e.g., peroxides or Ziegler–Natta catalysts). This type of reaction forms high-molecular-weight polymers such as polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), and polystyrene (PS).

By contrast, condensation polymerization involves monomers containing functional groups (such as –COOH, –OH, or –NH₂) that react together, releasing small by-products like water, methanol, or hydrogen chloride. Common examples include polyesters (e.g., PET) and polyamides (e.g., nylon).

Mixing and Shaping

This process mixes various melted materials to form a plastic product. After that, the mixture is converted into plastic pellets.

Plastic pellets will be extruded or shaped with a mold to become final or almost final products. The extrusion process can produce plastic products with various shapes and colors.

Types of Plastic and the Chemical Components

The majority of plastic products are made of polymers from petrochemicals and composed of monomer chains. Here are the types of plastic, their chemical components, and their properties:

Polypropylene (PP)

PP comes from propylene polymerization. This plastic is rigid and multifunctional. Usually, PP is used to produce car components and product packages.

Polyethylene (PE)

Polyethylene comes from ethylene polymerization, which includes HDPE and LDPE plastics. This plastic is flexible and bendable, making it suitable for producing food containers and plastic bags.

Polystyrene (PS)

PS is from styrene polymerization and has the properties of a rigid sponge. PS is typically used to create packing sponges.

Polyethylene Terephthalate (PET)

PET comes from ethylene glycol and terephthalic acid polymerization. It is light and strong, as well as the color is clear. PET is often used to produce plastic bottles.

Polyvinyl Chloride (PVC)

PVC is from the polymerization of vinyl chloride monomer. It is rigid, durable, and chemical-resistant. One example of PVC is a water pipe.

Polyamide (PA)

Polyamide comes from the condensation of amines and carboxylic acids. The properties are strong and abrasion-resistant. PA is used to create nylon fibers and vehicle components.

Polyester (PES)

Polyester is from the ester monomer polymerization. It is light and strong. Examples of polyester are clothes and coatings.

Polyurethane (PU)

PU comes from the reaction of polyol and isocyanate. PU can form bubbles and is multifunctional. One of the polyurethane products is cushioning foam. That is the information about what plastic is made of, the production process, and the type of plastic based on the monomers. It may be concluded that plastic is made of petroleum, natural gas, and cellulose, which are later processed with various chemical methods. 

Conclusion

Plastic has become one of the most essential materials in modern life, offering versatility, durability, and cost efficiency that few other materials can match. As discussed, most plastics are derived from petroleum and natural gas, with cellulose serving as an eco-friendly alternative for bioplastic production.

Through complex chemical processes such as refining, polymerization, and molding, these raw materials are transformed into a vast range of plastic types, each with unique properties suited for diverse industrial and consumer applications. Understanding what plastic is made of and how it is produced provides valuable insight into the material’s widespread use and its impact on our daily lives. Moving forward, continued innovation in plastic production and recycling technologies will be essential to achieving a more sustainable and environmentally responsible future.