Synthetic Fibers: Physical, Chemical  Properties and Application

Synthetic Fibers: Physical, Chemical  Properties and Application

Synthetic fibers are made using a range of chemicals, including oil-based ones. This means that it is easy to make or modify the fibers for specific end uses for both the consumer and the industrial market. The most well-known of the synthetic fibers are polyester and nylon. Lets discuss more about Synthetic Fibers Properties in below.

Classification and Properties:

Physical properties of synthetic fibers:

Chemical Properties of Synthetic Fibers

Synthetic fibers, unlike natural fibers, are crafted through chemical processes. This composition influences their interaction with various elements. Here’s a table summarizing the key chemical properties of some common synthetic fibers:

Classification of Synthetic Fiber:

Synthetic fibers are mainly three type

1. Synthetic polymers,
2. Natural polymers and
3. Others

1. Synthetic polymers

2. Natural polymers

Natural polymers are large, complex molecules composed of repeated subunits called monomers, which occur naturally in living organisms. These polymers play crucial roles in biological structures and processes and are fundamental to various industrial applications due to their biodegradability, biocompatibility, and renewable nature.

Application Of Natural polymers

Natural polymers have a wide range of applications across various industries due to their unique properties.

Medical and Pharmaceutical Applications

• Drug Delivery: Natural polymers like chitosan and alginate are used to create drug delivery systems that control the release of medication in the body.
• Tissue Engineering: Collagen and silk are used in tissue engineering to create scaffolds for growing new tissues.
• Wound Dressings: Natural polymers like alginate and chitosan are used in wound dressings for their biocompatibility and ability to promote healing.

Food Industry

• Food Additives: Natural polymers like pectin, carrageenan, and gelatin are used as thickeners, stabilizers, and gelling agents in food products.
• Edible Films: Starch and protein-based films are used for food packaging to reduce plastic waste.

Environmental Applications

• Biodegradable Plastics: Starch and cellulose are used to produce biodegradable plastics, which help reduce environmental pollution.
• Water Treatment: Chitosan is used in water treatment to remove pollutants and heavy metals due to its adsorption properties.

Textile Industry

• Fibers and Fabrics: Silk and wool are used to produce high-quality textiles known for their comfort and durability.
• Dyes and Finishes: Natural polymers are used to create eco-friendly dyes and finishes for fabrics.

Short overview of synthetic fibers are given below:

1. Polyester– Polyester is the most well-known of the synthetic fibers and one of the most widely used. It is a versatile fiber and can be blended with other fibers, such as cotton.
2. Nylon (polyamide)– Regarded as a modern fibre, it is very strong and robust. It can be easily mixed with other fibers and can be manufactured as long filaments or short, staple fibers, depending on its end use.
3. Acrylic- Acrylic is a soft, warm fabric that emulates wool in its handle and feel.
4. Elastane– Elastane is a rubber base material that can be used to add stretch and elasticity to products. The addition of elastane to clothing adds what is known as the ‘comfort factor’. The best known of the elastane fibres is Lycra®.
5. Aramid– Aramid fibres are very strong and are used for a variety of protective products. The most well-known of the aramid fibres are Kevlar® and Nomex®.
6. Acetate – One of the families of man-made cellulosic fibers, made from wood pulp or cotton. Acetate fabrics have a luxurious and lustrous appearance. They are fast-drying and can be either crisp or soft to touch, depending on the end use. Used to line garments, in lingerie and in fashion garments.
7. Tencel® – A staple or filament fibre that is made using an ‘environmentally friendly’ manufacturing process (recycling).
8. Viscose – regenerated fibre that is cellulose based.
9. Regenerated fibers-Regenerated fibres are also known as manufactured or man-made cellulosic fibres. They are either made from cotton linters, short cotton fibres too short to spin, or pine wood. The cellulose base is mixed with a chemical mixture, which is then converted into a fibre.

Details Classification of Synthetic Fibers

Synthetic fibers can be broadly classified into several categories, primarily based on their Chemical Structure

Chemical structure:

1. Polyamide Fibers (Nylons)
2. Polyester Fibers
3. Polyacrylic Fibers
4. Polyolefin Fibers (Polyethylene and Polypropylene)
5. Polyurethane Fibers (Spandex)
6. Specialty Fibers (e.g., Aramid, Carbon Fibers)

Physical Properties

1. Polyamide Fibers (Nylons)

• Strength: High tensile strength, excellent abrasion resistance.
• Elasticity: Good elasticity, retains shape well.
• Moisture Absorption: Low moisture absorption, quick-drying.
• Thermal Properties: Melts at high temperatures, prone to melting and shrinking when exposed to excessive heat.

2. Polyester Fibers

• Strength: Strong and durable.
• Elasticity: Excellent elasticity, maintains shape and resists wrinkling.
• Moisture Absorption: Very low moisture absorption, hydrophobic.
• Thermal Properties: Resistant to shrinking and stretching, good thermal stability.

3. Polyacrylic Fibers

• Strength: Moderate strength, good bulk and warmth.
• Elasticity: Good elasticity, soft and wool-like feel.
• Moisture Absorption: Low moisture absorption, dries quickly.
• Thermal Properties: Resistant to heat and sunlight, good insulating properties.

4. Polyolefin Fibers (Polyethylene and Polypropylene)

• Strength: High strength-to-weight ratio.
• Elasticity: Low elasticity, maintains shape well.
• Moisture Absorption: Extremely low moisture absorption, highly hydrophobic.
• Thermal Properties: Low melting point, excellent thermal insulation.

5. Polyurethane Fibers (Spandex)

• Strength: High elasticity and strength.
• Elasticity: Exceptional stretchability, can stretch up to five times its original length.
• Moisture Absorption: Low moisture absorption.
• Thermal Properties: Sensitive to high temperatures, maintains elasticity in a wide range of temperatures.

6. Specialty Fibers (e.g., Aramid, Carbon Fibers)

• Strength: Extremely high tensile strength, high durability.
• Elasticity: Low to moderate elasticity.
• Moisture Absorption: Varies with fiber type, generally low.
• Thermal Properties: Excellent heat resistance, flame retardant (Aramid), high thermal stability (Carbon fibers).

Chemical Properties

1. Polyamide Fibers (Nylons)

• Chemical Resistance: Good resistance to alkalis, moderate resistance to acids.
• Degradation: Prone to degradation by ultraviolet light.

2. Polyester Fibers

• Chemical Resistance: Excellent resistance to acids, alkalis, and most solvents.
• Degradation: Resistant to mildew, mold, and rot.

3. Polyacrylic Fibers

• Chemical Resistance: Good resistance to most chemicals.
• Degradation: Susceptible to static buildup, resistant to moths and fungi.

4. Polyolefin Fibers (Polyethylene and Polypropylene)

• Chemical Resistance: Excellent resistance to most chemicals, including acids and alkalis.
• Degradation: Highly resistant to environmental stress cracking.

5. Polyurethane Fibers (Spandex)

• Chemical Resistance: Good resistance to body oils, lotions, and detergents.
• Degradation: Susceptible to degradation by chlorine and ultraviolet light.

6. Specialty Fibers (e.g., Aramid, Carbon Fibers)

• Chemical Resistance: Aramids are highly resistant to organic solvents and chemicals; Carbon fibers are inert and resistant to most chemicals.
• Degradation: Aramids are flame-resistant; Carbon fibers do not degrade under normal conditions.

Applications of Synthetic Fibers

1. Polyamide Fibers (Nylons)

• Applications: Apparel (hosiery, swimwear, activewear), industrial uses (ropes, fishing nets, seat belts), carpets, and home furnishings.

2. Polyester Fibers

• Applications: Clothing (outerwear, sportswear), home textiles (curtains, upholstery), industrial uses (tire cords, conveyor belts), and packaging materials (PET bottles).

3. Polyacrylic Fibers

• Applications: Knitwear (sweaters, socks), blankets, upholstery, outdoor fabrics, and craft yarns.

4. Polyolefin Fibers (Polyethylene and Polypropylene)

• Applications: Geotextiles, agricultural products (crop covers), industrial fabrics (filter fabrics, ropes), and hygiene products (diapers, wipes).

5. Polyurethane Fibers (Spandex)

• Applications: Stretchable clothing (activewear, swimwear, undergarments), medical textiles (bandages, compression garments), and performance fabrics.

6. Specialty Fibers (e.g., Aramid, Carbon Fibers)

• Applications: Protective clothing (firefighter suits, bulletproof vests), aerospace and automotive industries (composite materials), sports equipment (racquets, bicycles), and high-performance engineering applications.

Takeaway

Natural polymers are large, complex molecules composed of repeated subunits called monomers, which occur naturally in living organisms. These polymers play crucial roles in biological structures and processes and are fundamental to various industrial applications due to their biodegradability, biocompatibility, and renewable nature