Polymers are substances consisting of several, or repeating chains consisting of individual atoms or molecules (i.e. interlinked). These substances can either be biological (i.e. cellulose, latex, rubber) or can made be artificial, or synthetic (i.e. nylon, polyethylene, polypropylene).
The terms “polymer” and “plastic” are also both used interchangeably to describe these substances, and there are substantial differences between them. Plastics are a type of polymer that is hydrocarbon – based from crude oil or natural gas.
Plastics are a type of polymer, but it is not the only type of polymer. There are differences between polymers vs. plastics and also recyclability, flexibility, and strengths. This paper will define the terms polymer and plastic, and explore the differences between the two.
What Is Polymer?
A polymer is a chemical compound that has, natural or synthetic, repeating strings of large molecules with chemical bonds that are known as monomers. Polymers may either be homopolymers (polymers of a monomer type) or copolymers (polymers with more than one type).
Polymers or combinations of polymers are the building blocks of a myriad of materials in the universe from biopolymers such as proteins and nucleic acids to minerals such as quartz and diamond to synthetic materials such as plastics, papers, and rubbers. Adam Williams, Brethour(ii).
What Is Polymer Made Of?
Polymers are chains of molecules, fabricating chemically bonded monomers. Monomers can be simple as a few atoms, or complex as functional groups of atoms. The chemical composition and size of the individual monomers determines how the polymer interacts internally as well as with its environment.
What Are the Properties of Polymer?
The properties of polymers differ based on their chemical composition. However, the general properties of polymers are listed below:
- Polymers have more tensile strength because they have longer chains and more cross-linking.
- Polymers have larger melting and boiling points because of their long chains and better intermolecular forces.
- Polymers are resistant to chemicals since they have a low reactivity.
- Polymers can be found using hydrogen and ionic bonds.
- The crystal structure of polymers is usually semi-crystalline and amorphous.
What Is the Structure of Polymer?
There are three types of polymer structures: linear, branched, and network, or cross-linked. Linear is a chain of monomers that the backbone is typically called in the branched and cross-linked structural types.
Bonded to the backbone are other elements or compounds that are most commonly hydrogen, fluoride, chlorine, boron, and iodine.
The bonded elements or compounds are referred to as pendant groups, and they hang from the chain of carbon atoms akin to charms on a bracelet. This is considered a branched polymer.
Depending on the number of valence electrons available in the pendant groups’ elements or compounds, the pendant groups have another possibility to attach or cross-link to other parallel chains of molecules.
These polymers are referred to as network polymers. Short cross-linkages will make for stronger polymers, and longer cross-linkages will make for a more flexible polymer.
What Is the Advantage of Polymer Compared to Plastic?
There are a number of advantages of polymer compared to plastic. The following demonstrates some advantages:
- Natural polymers do not come from crude oil.
- Natural polymers do not emit toxic fumes when burned.
- All Polymers are more sustainable than plastics since they are more biodegradable than synthetic plastics.
What Are Examples of Polymers?
Polymers exist all around us: they occur in every living organism, and in rocks and minerals, etc. Some examples of polymers are listed below:
- Cellulose and lignin are natural polymers that define the form of plants and trees.
- Nylon, polypropylene and polyethylene are synthetic polymers classified as thermoplastics.
- Elastomeric materials such as rubber and latex.
What Is Plastic?
Plastics are synthetic polymeric material that are derived from petroleum. Plastics using a polymerization or polycondensation process to produce. In these processes, oil and natural gas are refined to create gases and further refined to monomers like ethylene and propylene.
Ethane and propane are heated to form ethylene and propylene, and then mixed with a catalyst to form a polymer. The mixture is extruded, cooled and cut into pellets which are shipped to plastics manufacturing companies worldwide.
What Is Plastic Made Of?
Plastic is derived from organic raw materials which are primarily crude oil, although they can also come from coal, natural gas or cellulose.
Crude oil is a hydrocarbon substance that, when refined, is separated into several different materials or fractions, separating them based on size and structure of the molecules contained in each material. Naphtha, is derived from the oil refining process and is used primarily for plastics production.
What Are the Properties of Plastic?
Plastics are characterized as either thermoplastics or thermosets. The properties vary according to the plastic or thermoset, but the following list of general properties is available.
- Thermoplastics are materials that melt after being heated over their melting point and can be cooled and heated multiple times.
- Thermosets are plastics that remain solid after curing and do not melt, even when exposed to elevated temperatures.
- Plastics are chemically stable.
- Plastics have low thermal and electrical conductivity.
- Plastics have a high strength-to-weight ratio.
What Is the Structure of Plastic?
As plastics are polymers, they will have the same base structures as polymers. Plastics may be linear polymers (such as PVC), branched polymers (such as low density polyethylene), or cross-linked polymers (such as bakelite and melamine).
The structural type and chemical composition of the monomers that form the plastic determines the structural type of the plastic as a polymer.
Plastics will be either amorphous (the polymer chains in an unorganized fashion) or semi-crystalline (the polymer chains ordered but mixed within amorphous regions).
What Is the Advantage of Plastic Compared to Polymer?
Compared to polymer, there are many benefits of using plastic. The list Below describes just a few of those benefits:
- Production cost is relatively low
- Large quantities of plastic products can be produced very quickly and at mass scales are much lower than typical glass products
- Plastic has a very high strength to weight ratio
- Plastic is versatile. It can utilized as a consumer products, and is heavily used in industries including automotive, medical, aerospace, and heavy machinery, etc.
What Are Examples of Plastics?
Some examples of plastics are listed below:
- Nylon
- Low-density polyethylene (LDPE)
- PVC
- Polyoxymethylene (POM)
- Polypropylene (PP)
Which Is Better for 3D Printing, Polymer or Plastic?
It is difficult to determine whether polymer or plastic is the better material for 3D printing, as it largely depends on how the 3D-printed part will be used. Polylactic acid (PLA) is one of the most popular biodegradable polymers used in 3D printing to produce short life-cycle, non-load-bearing parts, such as those that may be created by hobbyists.
Compared to plastics, polymers have a wide range of properties. Acrylonitrile Butadiene Styrene (ABS), a thermoplastic polymer known for its toughness, durability, and impact resistance, is used for 3D-printing Lego bricks, toy parts, electronic enclosures, and automotive parts.
The polymer 3D-printing process is different from plastic 3D printing. As with polymers, some plastics may be more complicated to print than others and vice versa.
What Are the Advantages of Using Polymer in 3D Printing?
There are several benefits to using polymers in 3D printing.
- Natural polymers (e.g., gelatin, alginate) can be used to 3D print cell-laden hydrogels to form human tissues and organs.
- Natural polymers are included as fillers in plastic 3D-printing filaments to lessen the negative environmental effects of plastics and improve biocompatibility.
What Are the Advantages of Using Plastic in 3D Printing?
The benefits outlined below are advantages of plastic should you use it in your 3D printing applications:
- Generally, 3D printing with plastics produces strong and lightweight parts.
- There are a number of applications for which some of the parts could be plastic rather than metal when 3D-printing.
- In the 3D printing world, printing plastic is an ideal way to complete circuitry, prove concepts, and prototype new formats.
What Are the Disadvantages of Using Polymer in 3D Printing?
One disadvantage of using polymers in 3D printing is that a limited number of polymers are available for 3D printing.
What Are the Disadvantages of Using Plastic in 3D Printing?
Here are the drawbacks of plastic in the 3D printing process:
- The availability of plastics for 3D printing is restricted to a limited selection.
- 3D printing many plastics produces harmful fumes.
- Using non-biodegradable plastics in 3D printing can damage the environment when many 3D printed objects are for single use or proof of concept.
Why Is Polymer Better Than Plastic?
Polymers are superior to plastics, as many examples are more flexible, sustainable, and biocompatible. As one example, polymers made from natural resources such as lignin, cellulose, silk, and cotton are found in clothing, textiles, coatings, and adhesives because of their flexibility.
Due to the fact that they are naturally based, they break down significantly faster in nature than biodegradable plastics.
Furthermore, there are some polymers such as polyurethane and polyethylene glycol which are found in drug delivery systems and medical implants through their biocompatibility.
Plastics are not completely useless/terrible either. In conclusion, which is better polymer vs. plastic, is based on usage and volume of parts needed.
Frequently Asked Questions About Polymers and Plastic
Are Polymers Stronger Than Plastic?
No, polymers are not stronger than plastic. However, the answer largely depends on the items being compared.
Are Polymers Considered Plastic?
Yes, all petroleum-based polymers, including thermoplastics and thermosets, can be labeled as plastics. On the reverse side, those naturally occurring polymers such as cellulose, proteins, and cotton cannot be labeled as plastics.
Are All Polymers Plastics?
No, not all polymers are plastics. However, all plastics are again classified as polymers indeed. All plastics have repeating units of chains of molecules derived from petroleum.
What Polymers Are Not Plastic?
Plastics are not non-petrochemical, examples include: wool, paper, wood (cellulose), silk, and natural rubber.
What Is the Difference Between Polymers and Plastics in Terms of Tensile Strength?
The tensile strength of a polymer vs. a plastic, comes from the crystal structure of the items being compared. Tensile strength is the maximum strength that a material can tolerate when being pulled before fracturing. The crystal structure of the material has a significant effect on its tensile strength; typically, materials with a more compacted crystal structure with more slip systems will be more ductile and have a higher tensile strength.
What Is the Difference Between Polymers and Plastics in Terms of Hardness?
Hardness refers to a material’s resistance to localized deformation. When comparing hardness for polymers vs. plastics, plastics are generally harder than polymers as many plastics are cross-linked copolymers and made from different monomers. Cross-linking makes plastics less susceptible to localized deformation. Refer to our definition of Hardness for more information on hardness and other material properties.
What Is the Difference Between Polymers and Plastics in Terms of Impact Strength?
Impact strength refers to the ability of a material to withstand fracture due to an applied load or shock. The impact strength of polymers vs. plastic is often dependent mostly on the crystal structure of the material. Semi-crystalline plastics are typically more impact resistant than polymers because of the tightly packed crystal structure that is harder and more stable against deformation.