Styrenic Block Copolymers (TPS) are a class of thermoplastic elastomers (TPEs) composed of alternating hard and soft polymer segments. The hard segments are made of polystyrene (PS), while the soft segments consist of rubber-like elastomers such as polybutadiene (PB) or polyisoprene (PI). This structure gives TPS materials the elasticity of rubber while maintaining the easy processability of thermoplastics.

Structure

Styrenic block copolymers (TPS) have a phase-separated structure composed of alternating hard and soft polymer segments. The hard segments consist of polystyrene (PS) domains, which provide strength, rigidity, and thermal stability, while the soft segments are made of elastomeric materials such as polybutadiene (PB), polyisoprene (PI), or ethylene-butylene (EB), contributing to flexibility and elasticity. These block copolymers form a physical crosslinking network where the polystyrene blocks aggregate into discrete domains, acting as physical anchors that hold the material together, while the rubbery segments remain continuous and provide elasticity. This unique morphology allows TPS materials to behave like thermoset elastomers at room temperature but soften and flow when heated, making them fully thermoplastic and easily reprocessable. The phase separation between the polystyrene and elastomeric segments gives TPS its characteristic combination of strength, flexibility, and processability, making it widely used in applications requiring both durability and soft-touch properties.

Properties

Styrenic block copolymers (TPS) exhibit a unique combination of elasticity, strength, and processability due to their phase-separated structure. They have excellent flexibility and rubber-like elasticity, allowing them to stretch and recover their shape without permanent deformation. Their mechanical properties include good tensile strength and impact resistance, making them durable for various applications. TPS materials have moderate heat resistance, generally performing well below 100°C, and are resistant to many oils, greases, and chemicals, enhancing their stability in demanding environments. They also have good adhesion properties, making them suitable for overmolding onto other plastics. Unlike thermoset rubbers, TPS materials are thermoplastic, meaning they can be melted, reshaped, and recycled multiple times, improving manufacturing efficiency and sustainability. They also provide a soft-touch feel, making them ideal for grips, handles, and other ergonomic applications. Additionally, TPS offers good weather resistance, especially in formulations like SEBS, which enhance UV and oxidation stability. These combined properties make TPS widely used in automotive, medical, consumer goods, and adhesive applications.

Application

• Automotive Industry:
  • Soft-touch interior components (dashboards, door panels)
  • Seals, gaskets, and vibration dampeners
  • Grip pads and protective coatings
• Consumer Goods:
  • Handles and grips for tools, toothbrushes, and razors
  • Sports equipment, shoe soles, and protective gear
  • Flexible packaging and stretchable films
• Medical Applications:
  • Medical tubing and syringe plungers
  • Overmolded soft-touch medical devices
  • Flexible, biocompatible components
• Adhesives and Sealants:
  • Pressure-sensitive adhesives (PSAs)
  • Hot-melt adhesives for packaging and footwear
• Electronics & Electrical:
  • Protective casings for devices
  • Wire and cable insulation

Advantages 

High Elasticity and Flexibility – Provides rubber-like stretch and softness Good Impact and Tensile Strength – Enhances durability and wear resistance Thermoplastic Nature – Can be easily melted, reshaped, and recycled Soft-Touch Feel – Ideal for ergonomic grips and overmolding Good Adhesion to Various Materials – Suitable for multi-material applications Resistant to Oils, Greases, and Chemicals – Performs well in harsh environments Lightweight – Reduces material costs and improves energy efficiency Good Weather and UV Resistance – Certain formulations (e.g., SEBS) have enhanced outdoor durability Easy Processing – Compatible with injection molding, extrusion, and blow molding

Disadvantages 

Lower Heat Resistance – Limited performance above 100°C Lower Stiffness Compared to Some Plastics – May require reinforcement for structural applications Can Become Sticky in Hot Conditions – Some grades may soften and lose shape retention Higher Cost Than Standard Plastics – More expensive than traditional polyolefins like PP and PE Limited Load-Bearing Capacity – Not suitable for heavy-duty mechanical applications

Thermoplastic Polyolefins (TPO) are a class of polyolefin-based thermoplastic elastomers that combine the properties of polypropylene (PP), polyethylene (PE), and elastomers. They are widely used in various industries due to their durability, flexibility, chemical resistance, and ease of processing.

Structure

Thermoplastic polyolefins (TPOs) have a heterogeneous polymer structure, consisting of a semi-crystalline polypropylene (PP) matrix blended with amorphous elastomeric domains, typically ethylene-propylene-diene monomer (EPDM) or ethylene-propylene rubber (EPR). The PP component provides rigidity, thermal stability, and strength, while the elastomeric phase contributes flexibility, impact resistance, and toughness. Unlike copolymers, TPOs maintain a phase-separated microstructure, where the rubber particles are dispersed within the PP matrix rather than chemically bonded. This structure allows TPOs to remain thermoplastic, meaning they can be melted and reprocessed without undergoing permanent chemical cross-linking. Additionally, the presence of optional fillers such as talc, glass fibers, or carbon black can modify properties like stiffness and durability. The balance between the crystalline regions of PP and the amorphous elastomer phase gives TPOs their unique combination of strength, flexibility, and recyclability, making them ideal for applications in automotive parts, roofing membranes, and flexible packaging materials.

Properties

Thermoplastic Polyolefins (TPOs) possess a unique combination of mechanical, thermal, chemical, and electrical properties that make them highly versatile in various applications. Mechanically, they offer high impact resistance, good flexibility, and moderate stiffness, thanks to the combination of a semi-crystalline polypropylene (PP) matrix and elastomeric components such as ethylene-propylene rubber (EPR) or EPDM. They also exhibit excellent tear and abrasion resistance, making them durable in demanding environments. Thermally, TPOs can withstand temperatures up to 120–140°C, with a relatively low melting point (~165°C for the PP phase), allowing for easy processing via injection molding, extrusion, and thermoforming. Chemically, they are highly resistant to oils, greases, solvents, acids, and bases, and with proper stabilization, they offer good UV and weather resistance, making them suitable for outdoor applications such as automotive exteriors and roofing membranes. Additionally, TPOs have low water absorption, ensuring dimensional stability in humid conditions. Electrically, they function as good insulators, making them useful in select wire and cable applications. Their thermoplastic nature allows for melting and reshaping, making them highly recyclable and environmentally friendly compared to traditional thermoset rubbers. Moreover, TPOs are lightweight, contributing to fuel efficiency in automotive applications and reducing material costs. These combined properties make TPOs ideal for automotive bumpers, flexible packaging, consumer goods, and construction materials.

Applications of Thermoplastic PolyOlefins

• Automotive Industry:
  • Bumpers and fascias
  • Interior trim panels and dashboard components
  • Weather seals and underbody shields
  • Lightweight structural parts for fuel efficiency
• Roofing & Construction:
  • TPO roofing membranes (waterproof and UV-resistant)
  • Flexible building materials and siding
  • Window and door seals
• Consumer Goods:
  • Sporting equipment (e.g., soft-touch grips, protective gear)
  • Medical components (due to chemical resistance)
  • Household items like storage bins and furniture components
• Packaging Industry:
  • Rigid and flexible food containers
  • Industrial packaging solutions
• Electrical & Electronics:
  • Wire and cable insulation
  • Protective casings for devices

Advantages of Thermoplastic PolyOlefins

High Impact Resistance – Absorbs shocks and mechanical stress effectively Flexible Yet Durable – Balances elasticity with structural integrity Excellent Weather & UV Resistance – Ideal for outdoor applications Good Chemical & Water Resistance – Resists oils, solvents, and moisture Lightweight – Reduces material costs and improves fuel efficiency in vehicles Easy to Process & Mold – Can be injection molded, extruded, or thermoformed Thermoplastic & Recyclable – Can be reprocessed, making it an eco-friendly choice Cost-Effective – Lower production costs compared to thermoset rubbers

Disadvantages of Thermoplastic PolyOlefins 

Lower Heat Resistance – Limited to around 120–140°C, making it unsuitable for high-heat applications Lower Stiffness Compared to Some Plastics – May require reinforcement (e.g., glass fibers) for structural strength Surface Finish Limitations – May require coatings or treatments for improved aesthetics Difficult to Bond with Adhesives – Requires specialized bonding techniques due to low surface energy Can Become Brittle in Extreme Cold – Some formulations may lose flexibility at very low temperatures