The electrolytic iron powder has a wide range of applications in various industries due to its high purity, controlled particle size, excellent surface areas and lesser impurity profile. Food grade iron powders are used as fillers to increase the strength of polymers as the presence of iron powder makes the polymer component very rigid and sturdy for various applications. Polymers consist of high resilience molded and extruded components that are made by injecting the iron powder as uniformly distributed filler. This way the dual characteristics of polymer and iron are derived.
What are Fillers?
Fillers are particles added to resin or binders such as plastics, composites, concrete, polymers that can improve specific properties, make the product cheaper or a mixture of both. A filler is a solid additive incorporated into a polymer matrix to alter its mechanical properties. Fillers are basically classified into two types – Functional fillers and Extenders.
- Functional fillers: They are used to improve the performance of the material. When functional fillers are added to the polymer matrix, a particular property of the material gets improved up to a certain extent as the % of filler increases. For example – glass fiber is used with nylons to improve its tensile properties and stiffness.
- Extenders: They are used specially to reduce the cost of the raw material. When they are added to the polymer matrix, no improvement or very less improvement can be observed in properties, only the density of the material increases. The fillers with high specific gravity occupy the volume in the polymer matrix with low specific gravity. For example – Calcium carbonate filled PP.
How are fillers added to polymers?
The fillers can blend with the polymer in high temperature by extruder or mixer. The dispersed state of fillers depends on the diameter of the fillers and the compatibility between the filler and the polymer. For most of the inorganic fillers, blending is not a good method. The other method is in-situ polymer synthesis for most inorganic fillers. The fillers can disperse uniformly, and the diameter can be less than 100 nanometer, which is an important method for making nano materials.
Types of Strength of Polymers:
When talking about polymers, you should know that there is more than one kind of strength. There is tensile strength, compressional strength, and flexural strength. Tensile strength is important for a material that is going to be stretched or put under tension. A polymer sample has compressional strength if it is strong when one tries to compress it under pressure. Concrete is a perfect example of a material with good compressional strength. A polymer sample is said to have good flexural strength if it is strong when one tries to bend it.
How high purity electrolytic iron powders are used as fillers to increase the strength of Polymers:
According to the Microstructural study, food grade iron powder particles are easily dispersed in the Polypropylene matrix. It also shows that with an increase in iron content in the composites, the hardness of polymers also increases. When electrolytic iron powders are used as fillers, the polymers undergo various changes that are as follows:
- Dielectric constant and dissipation factor increase with an increase in iron content in the matrix.
- With the addition of iron powders in the polymer matrix, thermal stability also increases significantly. A convenient method of evaluating the thermal stability of polymers is to measure the temperature of the maximum rate of polymer degradation, under an inert gas atmosphere.
- Melting Temperature of PP/Fe composites decreases with the addition of iron content while crystallization temperature is increased.
- Some polymers, notably polyolefins and polyamides, are semi-crystalline in nature. Others, such as natural rubber, crystallize on the extension. Percentage crystallinity increases with the addition of electrolytic iron powder in Polypropylene matrix.
- Food grade iron powder is also used as a uniform filler substance to increase the weight like of a plastic or polymer mold for specific engineering tasks. It is generally found that properties such as impact strength are less degraded when the polymer molecular weight is high, providing this does not lead to compounding problems.
- Storage modulus increases with the addition of iron content in Polypropylene matrix.
Conclusion:
The addition of fillers alters most properties of polymers, some beneficially, others detrimentally. Electrolytic iron powders have been found very effective in terms of increasing the strength of different types of polymers.
