Top 5 Benefits of Polymer Additives
Polymer additives are chemicals added to the base polymer to improve processability, reduce raw material costs, prolong the life span, and/or achieve the desired physical or chemical properties in the final product. There are many additive options available and each one offers a specific improvement to the polymer’s functionality or stability. Below are the top five benefits of polymer additives. In addition to the improvements listed below, polymer additives can also be used to provide the desired color, odor, crystallization rate, density, insulation, anti-static, anti-microbial, and many other properties.
- Improved Processing: these additives are combined with the polymer to improve the processability and processing characteristics of the material. Internal and external lubricants are very common processing additives that improve processing efficiency. Internal lubricants improve the polymer flow properties and mold filling by reducing friction within the polymer blend itself; examples of internal lubricant additives are fatty esters and waxes. External lubricants migrate to the surface of the polymer to reduce the friction between the plastic and the manufacturing equipment; examples of external lubricants are metallic soaps and fatty acids. Internal and external lubricants can be utilized together to achieve the desired processing characteristics. In addition to lubricants, there are other additives that can optimize processing properties. For example, de-molding agents can be used to facilitate better release from the mold. Examples of de-molding agents include silicone oils and graphite.
- Decreased Material Costs: fillers, or extenders as they are often called, are inexpensive additives that add bulk to the polymer and reduce costs by reducing the volume of base polymer consumed. Minerals are often used as fillers and examples include calcium carbonate, silica, glass fibers, and carbon black. Fillers can also impact the properties of the plastic such as enhancing its stability and moldability.
- Extended Life Span: nearly every plastic is prone to degradation when exposed to high temperatures, UV light from sunlight, and oxygen including ozone. This degradation can occur during processing or once the product is in service and the symptoms include brittleness, discoloration, and loss of physical properties that reduce the life span of the plastic. Additives, often referred to as anti-oxidants or stabilizers, are added to combat the deterioration of the plastic and to significantly extend the life span of the final product. UV stabilizers absorb UV light, protecting the plastic from its harmful effects. Anti-oxidant additives protect against oxidative degradation by minimizing the opportunity for free radicals to react with oxygen to form unstable molecules. Anti-oxidants, often called free-radical scavengers, react with the undesirable free radicals to prevent the reactions that lead to degradation; additionally, anti-oxidants destroy the locations on the polymer chain that are vulnerable to radical formation. Both forms these anti-oxidants are often used in tandem to achieve the desired stability. Examples of antioxidants include phenols, aryl amines, and phosphates, and examples of UV stabilizers include benzophenones and benzotriazoles.
- Reduced Flammability: flame retardants are additives that prevent, delay, or slow down combustion. Flame retardants can be organic or inorganic compounds that are either mixed with the base polymer, added during the plastic processing step, or as a surface layer finish on the final product. There are different methods that are used by the additives to reduce flammability such as creating a foam layer for extra insulation, chemical reactions to inhibit combustion, and decomposition reactions that produce water. Sometimes more than one flame retardant is used to improve the level of protection. These additives are common in electrical products to avoid the ignition and burning of plastics. Halogens such as bromines and chlorines as well as phosphorus and nitrogen chemistries are common flame retardants.
- Improved Flexibility: base polymers are often rigid and do not have the necessary flexibility and rheology, or flow, properties that are needed for plastics processing. Plasticizers are a type of additive added to improve rheology as well as elasticity. Plasticizers are one of the most common polymer additives and an example is phthalate esters used in PVC products. Plasticizers fit in the spaces between polymer molecules reducing intermolecular forces, leaving the polymer less rigid and more easily handled during manufacturing. Depending on the specific plasticizer, these additives can also impact other physical and mechanical properties of the plastic.
Amcor
Amcor is a manufacturer of polyethylene film and bags, as well as polyolefin compounds, additives, blends, and masterbatches. Amcor has grown from a single product line to hundreds of products and five product divisions. In addition to selling products, we also provide tech support, assistance with your equipment, and process recommendations. Below are some highlights of Amcor’s additive offerings.
| · Flame Retardants | · Rheology Modifiers – Amblend | · Antiblock & Fillers – Amblock |
| · Antistatic – Amstat | · Slip – Amease | · Stabilizers |
| · Processing Aids – Ampro | · Gas Diffusion Agents – Amage | · TiO2 – Amti |
| · Chemical Blowing Agents – Amcell | · Nucleating Agents – Amron | · Cross-Linking Agents |
| · Masterbatch Colors – Amtone | · Specialty Chemicals |
Amcor is also a full line distributor of various chemicals, resins, and gases for the plastic industry. With warehousing and distribution facilities across the United States, Mexico, Eastern Europe and China, we service companies of all sizes and locations across multiple industries.
Amcor realizes that quick turnaround, on time delivery, a quality product, and personal service are what it is all about. Contact us today to learn how we can assist with your next project!
What Are Polymer Additives?
What Are Polymer Additives?
Plastics manufacturing has evolved significantly over time. Plastics were originally produced using a few natural materials but now there are thousands of plastics formulated from a wide range of natural and synthetic materials. One of the big changes over time in plastic formulations is the use of polymer additives.
Additives are chemicals added to the base polymer to improve processability, prolong the life span, and/or achieve the desired physical or chemical properties in the final product. While the content of additives is typically only a few percent, their impact on polymer performance and stability is significant. Once the additives are added, the polymer blend is referred to as a masterbatch and is processed accordingly.
Types of Polymer Additives
There are countless options when it comes to additives and each one offers a specific improvement to the polymer’s functionality or stability. Selecting the right additives for your polymer may seem like a daunting task - this is why it is crucial to choose a partner, like Amcor, that has extensive expertise in various additives and resins as well as experience with state-of-the-art compounding and blending processes. Amcor will guide you through the selection process to ensure the right additives are chosen for your specific application.
Below are common categories of polymer additives. Even within a specific category, such as flame retardants, there are numerous additive options available; the additive that is best for a given plastic depends heavily on the base polymer (to ensure compatibility) and the application of the final product.
--> Plasticizers: base polymers are often rigid and do not have the necessary flexibility and rheology, or flow, properties that are needed for plastics processing. Plasticizers are added to improve rheology as well as elasticity. Plasticizers are one of the most common polymer additives and an example is phthalate esters used in PVC products.
--> Anti-aging stabilizers: nearly every plastic is prone to degradation when exposed to UV light, such as from sunlight, and oxygen including ozone. The degradation causes brittleness, discoloration, and loss of some physical properties. Additives, referred to as anti-oxidants, stabilizers, or anti-ozonants, are added to combat the deterioration of the plastic and to significantly extend the life span of the final product. Examples of antioxidants include phenols, aryl amines, and phosphates, and examples of UV stabilizers include benzophenones and benzotriazoles. Additionally, black is an excellent UV absorber so paints, dyes, or elemental carbon black are often added to protect products against UV light.
--> Blowing agents: these additives are added to the base polymer and when a specific temperature is reached during processing they decompose, releasing gas that forms a cellular structure within the plastic. This structure reduces density and improves insulation properties. There are many different blowing agents available from salts to complex nitrogen-releasing chemicals.
--> Flame retardants: flame retardants prevent, delay, or slow down combustion. These additives are common in electrical products to avoid the ignition and burning of plastics. Flame retardants can be mixed with the base polymer, or added during the plastic processing step, or even as a surface layer finish on the final product. Halogens such as bromines as well as phosphorus and nitrogen chemistries are common flame retardants.
--> Nucleating agents: these additives improve mechanical properties and transparency. They also speed up the plastic crystallization rate, reducing overall cycle time.
--> Processing: these additives are combined with the polymer to improve the processability and processing characteristics of the material. Examples of processing additives include lubricants, and more specifically, fatty acids, hydrocarbon waxes, and some types of polyethylene.
--> Anti-static: these additives are used to minimize the potential for static electricity build up on the surface of the plastic, and in some cases even prevent it entirely. Examples of anti-static additives include amines, ammonium compounds, and polyethylene glycol esters.
--> Colorants: the purpose of these agents is to change the color of the final product. These additives are often pigments or dyes. The specific dye or pigment selected is largely based on which base polymer is being used as the two materials have to be compatible.
--> Odor: there are also additives to modify the odor of the final product. An example of an odor agent is when a chemical is added to paints to produce a more pleasing smell.
--> Anti-microbial: given the increasing trend in implantable medical devices and other technologies, anti-microbial additives are becoming more popular. These agents protect against deterioration of the plastic and reduce the potential for a microbiological attack.
Amcor
Amcor is a manufacturer of polyethylene film and bags, as well as polyolefin compounds, additives, blends, and masterbatches. Amcor has grown from a single product line to hundreds of products and five product divisions. In addition to selling products, we also provide tech support, assistance with your equipment, and process recommendations.
Amcor is also a full line distributor of various chemicals, resins, and gases for the plastic industry. With warehousing and distribution facilities across the United States, Mexico, Eastern Europe and China, we service companies of all sizes and locations across multiple industries.
Amcor realizes that quick turnaround, on time delivery, a quality product, and personal service are what it is all about. Contact us today to learn how we can assist with your next project!