Related Blogs
The evolution of polymer additives has been significant in recent years. But first, what are polymers? They are long chains of molecules that make up plastics. On their own, polymers have limits, so this is where additives help. Additives improve the look, strength, and performance of plastics, making them more useful for different purposes.
Polymer additives are widely used in food and pharmaceutical packaging, automobile body panels, electronics, and agriculture (fertilisers, films). While traditional polymers lack antimicrobial protection, adding these substances can reduce bacterial growth by up to 99.9% in some applications.
In this blog, we’ll explore what polymer additives are, how they work, and the different types used in plastic manufacturing.
Understanding Polymer Additives in Plastic Manufacturing
Polymer additives are special chemicals mixed with plastics to modify or change their natural properties. These additives help plastics perform better for specific uses. The additives help plastics become:
- Chemically stable: Additives increase the plastic’s durability, making it more resistant to chemical reactions.
- Temperature-resistant: Additives allow plastics to withstand high or low temperatures without deforming. Plastics can then be used safely in applications involving heat or cold.
- Softer or stretchier: Additives can help plastics be more flexible to bend or stretch without breaking. It improves the usability of products like flexible tubing, packaging films, or wearable items.
- Harder: Additives can increase the strength of plastics, and they can withstand heavy usage, like in furniture or construction materials.
- Slippery: Additives can reduce friction on the plastic’s surface, improving processing and handling.
Polymer additives can be used at different stages of production. It can be either after the polymer is made or during the polymer-making process. They are classified into two types: internal and external.
Below is a table demonstrating internal vs. external polymer additives.
Classification | Definition | Effects | Examples |
Internal | These compounds are incorporated into the polymer during its production phase | Internal additives permanently improve properties like flexibility, stability, colour, or flame resistance without changing the polymer’s basic structure | Plasticisers, fillers, stabilisers, flame retardants, colourants |
External | These compounds are applied as surface coatings after the production of the polymer | External additives only change surface traits like chemical resistance or biocidal effects | UV-protective coatings, antimicrobial films, plasma treatments |
Different Types of Polymer Additives & Functions
Every polymer additive serves a distinct purpose, per se. Let us discuss the most common categories of polymer additives in detail.
Antimicrobial Additives
These additives, such as silver ions or copper, prevent microbial growth by inhibiting cellular functions. They provide continuous protection against bacteria and fungi. Applications include food packaging, water tanks, and medical devices.Stabilisers
Stabilizers protect plastics against environmental degradation. Antioxidants prevent oxidative brittleness, while UV stabilizers guard against ultraviolet (UV) radiation that causes strength loss and discoloration.Anti-Rodent Additives
These additives protect polymers from damage caused by rodents’ chewing and gnawing. They enhance the lifespan and flexibility of products, mainly used in automotive cables, wiring, and electrical panels.Plasticisers
Plasticisers increase flexibility by reducing intermolecular forces, making polymers more elastic and easier to process. They are commonly used in flooring, hoses, and cables.Blowing Agents
These additives lower the density of polymers by creating tiny gas bubbles during processing. This makes plastics lighter and improves insulation. They may be simple salts or nitrogen-releasing chemicals.Biodegradable Additives
Designed to promote decomposition, these additives help plastics break down faster in natural environments such as composting systems. They are useful in agricultural films and single-use plastic products.Fillers
Fillers enhance mechanical properties and reduce costs.Organic fillers: cellulose, wood flour (used for composites with unique properties).
Inorganic fillers: calcium carbonate, silica, talc (used to increase durability and stiffness).
Flame Retardants
Flame retardants provide resistance to fire by offering thermal stability, forming protective layers, or releasing flame-inhibiting gases. They are widely applied in construction materials, electronics, and textiles.Anti-Fog, Anti-Static, and Odor Removal Additives
These specialized additives serve packaging and electronic industries. Anti-fog prevents condensation on plastic films, anti-static reduces static electricity (especially for electronics), and odor-removal eliminates unpleasant smells from recycled plastics.
Importance of Polymer Additives
There are several reasons why manufacturers choose polymer additives. From reduced costs to improved flexibility, additives make processing simpler. Below are the benefits of polymer additives:
- Enhanced Performance: Plastics are prone to discolouration, brittleness, and loss of physical properties over time. Additives like stabilisers enhance strength and reduce plastic degradation, leading to higher performance and extended lifespan for polymers.
- Process Improvements: Additives boost polymer manufacturing efficiency by improving pellet or melt flow and mould filling. While internal lubricants reduce friction within the polymer, external lubricants prevent the plastic from sticking to machinery, and moulding agents ensure easy release from moulds.
- Health and Safety Compliance: Polymer additives meet strict standards, such as food-grade certifications and regulatory compliance with REACH and FDA requirements to ensure the safety of plastics used in sensitive applications like packaging and medical devices.
Criteria for Selecting the Right Additive
There are multiple factors to consider before selecting the right additives. The correct polymer additives allow plastics to remain effective and reliable over time. Here are the criteria for selecting the right additive.
-
Applicability
The chosen additive must be compatible with the production process to prevent issues such as machinery corrosion or unwanted reactions with other materials. It is also important to check the additive’s heat resistance, especially if the end product will face high-temperature conditions. -
Environmental Exposure
Additives should be evaluated for long-term stability against sunlight, temperature fluctuations, pressure, and other environmental factors. A good additive should not crystallise, migrate within the polymer, degrade, or compromise the plastic’s strength and performance over time. -
Regulatory Environment
When multiple additives are used in a formulation, they must be compatible with one another. Poor combinations can lead to discolouration, reduced performance, or deposits forming on the material. Even additives from the same category may interact negatively, making testing and validation critical.
NICHEM Solutions: Your Polymer Partner
Polymer additive formulations are unique to each customer’s application and needs. That’s where Nichem Solutions comes in, providing high-quality polymer additives. We meet the specific demands of manufacturers by incorporating fillers, plasticisers, stabilisers, and colourants to enhance the functionality of polymer-based materials.
About NICHEM
Long-standing Specialty Chemicals player with ISO 9001:2015 certification and a history of providing specialty solutions for over 25 years. The company is headed by senior chemical industry specialists with the combined expertise of more than 100 years. With an emphasis on eco-friendly, non-toxic products, the company’s primary strength is research, development, and customisation. More information on NICHEM can be found at https://nichem.solutions.
