Atman Polymer

Polycarbonate-ABS (PC-ABS) is an engineered thermoplastic alloy combining the strength and heat resistance of polycarbonate with the flexibility and processability of ABS (Acrylonitrile Butadiene Styrene). The balance of properties in PC-ABS alloys depends on the PC-to-ABS ratio, the molecular weight of the polycarbonate, and the use of specific additives. This alloy exhibits excellent flowability, processability, plating performance, and surface appearance. Compared to ABS, PC-ABS shows significantly improved heat resistance, impact strength, and performance in thin-walled applications.

The PC-to-ABS ratio is the key factor influencing the final product’s heat resistance. Due to its synergistic behavior, the PC-ABS alloy delivers superior impact resistance at low temperatures — outperforming both PC and ABS individually.

Main Features of PC-ABS

• General Characteristics:
  PC-ABS is a slightly amorphous, odorless, and non-toxic engineering thermoplastic. It typically has a density ranging between 1.1 and 1.2 g/cm³.

• Mechanical Properties:
  Offers excellent mechanical performance with outstanding impact resistance.

• Thermal Performance:
  Service temperature ranges from 60°C to 120°C, with a Heat Deflection Temperature (HDT) between 120°C and 140°C.

• Electrical Properties:
  Exhibits semi-insulating behavior.

• Flame Resistance:
  Possesses high flame-retardant capabilities.

• Environmental Stability:
  Demonstrates good stability under UV exposure and sunlight.

• Chemical Resistance:
  Resistant to acids and oils, but not resistant to alkalis, oxidizing acids, amines, or ketones. Soluble in aromatic chlorinated and hydrocarbon solvents.

• Hydrolysis Sensitivity:
  Highly sensitive to hydrolysis. Exposure to water at temperatures above 60°C can lead to hydrolytic degradation and cracking.

PC-ABS Alloy Overview

The Polycarbonate-ABS alloy blends two major engineering plastics—polycarbonate for its high heat and impact resistance, and ABS for its toughness at low temperatures and excellent processability. The result is a material suitable for demanding applications across various industries, such as automotive, electronics, home appliances, medical equipment, and information technology.

PC-ABS resins are available in different grades, including general-purpose, flame-retardant, and high-impact resistant types. Their ability to maintain high impact strength even at sub-zero temperatures, along with their superior heat resistance, makes them highly desirable in performance-critical applications.

Applications of PC-ABS Alloy

• Automotive Industry:
  Center consoles, instrument panels, interior/exterior trim parts, trunk components.

• Electronic Components:
  Switch housings, hair dryers, and other devices requiring impact resistance.

• Home Appliances & Consumer Electronics:
  TV housings, laptop monitor frames, handheld devices, LCD bezels, keyboard keys, adapters, chargers, and mobile phone bodies.

PC-ABS Processing Guidelines

• Pre-Drying:
  Pre-dry at 80–110°C for 3–4 hours to eliminate moisture.

• Thermal Stability:
  Begins degrading at around 300°C, releasing CO₂. Mechanical properties drop significantly beyond this temperature. Processing temperatures should be managed carefully.

• Injection Shot Size:
  Optimal shot weight is 35–65% of the injection cylinder capacity.

• Barrel Temperature:
  220–280°C depending on grade and part geometry.

• Mold Temperature:
  Recommended range is 70–100°C.

• Injection Speed:
  Slow to medium speeds are preferred for optimal surface quality.

• Mold Shrinkage:
  Typical shrinkage is 0.5–0.7%; for reinforced PC-ABS grades, shrinkage ranges from 0.2–0.4%.

• Post-Processing Capabilities:
  Suitable for printing, plating, bonding, coating, and machining. To relieve internal stresses, heat treatment at 80°C for 4 hours is recommended.

ABS stands for Acrylonitrile Butadiene Styrene, an engineered, amorphous thermoplastic known for its excellent impact resistance. ABS is composed of three monomers—acrylonitrile, butadiene, and styrene—each contributing specific properties to this terpolymer.

• Acrylonitrile: A synthetic monomer derived from propylene and ammonia. It enhances the chemical resistance and thermal stability of ABS.

• Butadiene: A monomer with rubber-like properties. It provides impact strength and toughness to the polymer.

• Styrene: Produced from ethylbenzene via dehydrogenation, it imparts rigidity and improves processability, as well as giving ABS its glossy surface.

The monomer ratios in ABS typically range from 15–35% acrylonitrile, 5–30% butadiene, and 40–60% styrene. The resulting polymer is a crosslinked network of polybutadiene and polystyrene, with dispersed poly(styrene-acrylonitrile) chains. The polar nitrile groups from neighboring chains attract one another, enhancing strength compared to pure polystyrene.

Styrene contributes a glossy and impermeable finish to the plastic. Polybutadiene provides toughness, especially at low temperatures. ABS generally performs well within the temperature range of 20–80°C (68–176°F), though its mechanical properties vary with temperature. This is due to the rubber phase, where fine elastomer particles are dispersed throughout a rigid thermoplastic matrix.

Key Features of ABS

The most important mechanical properties of Acrylonitrile Butadiene Styrene (ABS) are impact resistance and toughness. ABS sits between commodity plastics and engineering plastics in terms of performance. Its main properties include:

• High mechanical strength

• Excellent impact resistance, even at low temperatures

• Good electrical insulation

• Weldability and strong bonding capability

• Good abrasion and strain resistance

• High dimensional stability (maintains mechanical strength over time)

• Glossy appearance and excellent surface finish

• Very good resistance to dilute acids and alkalis

• Moderate resistance to aliphatic hydrocarbons

• Poor resistance to aromatic hydrocarbons, halogenated hydrocarbons, and alcohols

Impact resistance can be further improved by increasing the proportion of butadiene relative to styrene and acrylonitrile. However, altering the composition may negatively impact other characteristics. Therefore, ABS can be tailored into different grades based on application needs.

ABS Applications

Thanks to its lightweight and excellent processability, ABS is widely used across industries. It performs well in the 20–80°C temperature range. Its injection molding capabilities make it suitable for a variety of applications, such as:

• Drainage piping systems

• Musical instruments

• Automotive parts (e.g., bumper bars, dashboards, interior trim, door handles, seat belt components)

• Medical and drug delivery systems

• Electrical and electronic enclosures

• Consumer goods (e.g., suitcases, pens, toys like LEGO bricks)

• Home appliances (e.g., vacuum cleaner housings, food processor parts, refrigerator interiors)

• Computer hardware (e.g., keyboards, adapters)

• Fittings and pipes: ABS pipes are widely used due to their resistance to corrosion, rust, and decay, and because they are easy to install.

ABS Processing Guidelines

Injection Molding

• Pre-Drying: If moisture content is high, dry the material at 80°C for 4 hours. Signs of residual moisture include streaks, bubbles, or surface defects on molded parts.

• Melt Temperature: 210–270°C

• Mold Temperature: 40–70°C

• Injection Pressure: 50–100 MPa

• Injection Speed: Medium to high

Extrusion

• Pre-Drying: Dry the material at 70–80°C for 3 hours

• Extrusion Temperature: 210–240°C

• Screw Design: Recommended L/D ratio of 25–30

Chlorinated Polyethylene (CPE) is a modified form of polyethylene that contains approximately 34% to 44% chlorine incorporated into its polymer backbone. This unique composition provides CPE with a broad spectrum of properties, making it suitable for a wide range of industrial applications. In this article, we explore the structure, characteristics, and versatile applications of chlorinated polyethylene, emphasizing its importance in materials science and engineering.

Characteristics and Properties of Chlorinated Polyethylene

CPE is produced by chlorinating high-density polyethylene (HDPE), where hydrogen atoms are substituted with chlorine atoms. It is typically available as a white, non-toxic, tasteless powder. The density of CPE ranges from 0.93 to 0.96 g/cm³, and it has an average molecular weight of 5 to 25 million, with a melt index of 0.01–2.0 g/10 min.

The degree of chlorination significantly influences the properties of CPE:

• <15% chlorine: Behaves like a plastic.

• 16–24% chlorine: Exhibits thermoplastic-elastomer behavior.

• 25–48% chlorine: Functions as a rubber-like elastomer.

Increasing chlorine content enhances oil resistance, air impermeability, and flame retardancy, whereas decreasing it improves cold resistance and flexural strength. These tunable properties make CPE a highly adaptable material for specific performance requirements.

Applications of Chlorinated Polyethylene

One of the most significant applications of CPE is as an impact modifier in polyvinyl chloride (PVC). It enhances the impact strength of PVC products, making them suitable for demanding applications. In fact, approximately 74% of global CPE consumption in 2017 was in this role.

Other key applications include:

• Waterproof membranes

• Wire and cable jackets

• Automotive hoses and tubes

• Coatings

• Injection-molded parts

• Extruded profiles

Beyond its use in PVC formulations, CPE also functions as a standalone high-performance elastomer or in blends with other rubbers. It is used in:

• Electrical wires and cables

• Hydraulic hoses

• Impact-resistant plastic sheets and strips

• Refrigerator sealing strips

• Magnetic cards

• Semi-rigid and rigid plastic profiles

• ABS modification

• Pipe and fitting systems

• Tire compounds

Fillers such as calcium carbonate, clay, and talc are commonly used in CPE compounds to enhance specific properties and reduce cost.

Key Properties of CPE Resins and Elastomers

CPE offers excellent physical and mechanical performance, including:

1. Chemical, oil, and heat resistance

2. Excellent performance at low temperatures

3. High compressive and tensile strength

4. Flame retardancy

5. High filler acceptance

6. Abrasion resistance

7. Good environmental aging resistance

CPE materials range from rigid and crystalline resins to soft, flexible elastomers, enabling a wide array of formulations tailored for various industries.

Conclusion

Chlorinated Polyethylene (CPE) is a versatile polymer that has become indispensable across multiple industries. Its adaptability, excellent mechanical properties, and chemical resistance make it a key ingredient in enhancing the durability, performance, and functionality of polymer-based products.

From PVC impact modifiers to elastomeric materials for cables, hoses, and sealing systems, CPE continues to drive innovation in materials engineering. As technological advancements evolve, CPE stands as a testament to the power of polymer modification in addressing modern material challenges and creating high-performance, future-ready products.

Polypropylene compounds are thermoplastic resins produced by blending one or more base polyolefins with various functional components such as impact modifiers, fillers and reinforcements, pigments, and additives. These PP compounds offer a broad spectrum of properties and are widely used in automotive, electrical appliances, building and construction, and furniture components.

Structure and Behavior of Polypropylene Compounds

Polypropylene compound shares similarities with polyethylene, particularly in solution behavior and electrical characteristics. However, the presence of methyl groups in polypropylene enhances its mechanical strength and thermal resistance, albeit at the expense of reduced chemical resistance. In isotactic polypropylene, the methyl groups are aligned on one side of the carbon backbone, resulting in higher crystallinity. This configuration makes it firmer and more resistant to creep compared to atactic polypropylene and polyethylene.

Introduction to Polypropylene (PP)

Polypropylene (PP) belongs to the polyolefin family and is among the three most widely used thermoplastics globally. PP compounds are utilized across many applications, such as:

• Automotive industry

• Industrial applications

• Consumer goods

• Furniture and household products

One notable advantage of PP is its low density, the lowest among commodity plastics.

Polypropylene Polymer Structures

Based on the spatial arrangement of methyl groups (CH₃) on the polymer chain, polypropylene is classified into:

• Atactic PP: Irregular methyl group arrangement

• Isotactic PP: Methyl groups aligned on one side of the chain

• Syndiotactic PP: Alternating methyl group arrangement

Types of Polypropylene Compounds

1. Homopolymer Polypropylene

This is the most commonly used grade and consists of only propylene monomers. It has a semi-crystalline structure and is widely used in:

• Packaging

• Textiles

• Healthcare products

• Piping systems

• Automotive parts

• Electrical insulation

2. Copolymer Polypropylene

There are two main subtypes of copolymers:

• Random Copolymer PP: Produced by copolymerizing ethylene and propylene, with ethylene units randomly distributed (up to 6%). These PP compounds are flexible and optically transparent, ideal for transparent applications or products requiring aesthetic appeal.

• Block Copolymer PP: Contains a higher ethylene content (5–15%) arranged in regular blocks. These compounds offer higher strength but are less flexible, making them suitable for structural and industrial uses.

PP copolymers are commonly used in:

• Packaging

• Home appliances

• Pipes and films

• Electrical components

• Automotive applications requiring impact resistance

3. Terpolymer Polypropylene

Terpolymers consist of propylene, ethylene, and butene units randomly distributed along the chain. These poly propylene compounds exhibit enhanced clarity and reduced crystallinity, making them ideal for sealing films and transparent packaging.

4. High Melt Strength Polypropylene (HMS PP)

HMS PP is modified to include long-chain branching, offering high melt strength and melt phase elasticity. These PP compounds feature:

• Excellent foamability

• Good chemical resistance

• High thermal stability

They are widely used in:

• Food packaging foams

• Automotive components

• Construction materials

Disadvantages of Polypropylene Compounds

Despite its versatility, polypropylene compound has several limitations:

• Poor resistance to UV radiation, impact, and scratches

• Limited service temperature range (90–120°C)

• Tendency to swell in chlorinated and oxidizing environments

• Poor paint and coating adhesion

Applications of Polypropylene Compounds

1. Packaging

Polypropylene is widely used in packaging due to its high strength, low cost, and moisture barrier properties. It is ideal for:

• Food packaging (films, containers, shrink wraps)

• Electronic and graphic films

• Disposable closures (e.g., diaper tabs)

• Cast and BOPP (biaxially oriented polypropylene) films

2. Consumer Goods

PP compounds are used in:

• Transparent containers

• Appliances and household items

• Toys and suitcases

• Furniture components

3. Automotive Industry

Thanks to its cost-effectiveness, moldability, and mechanical performance, PP is essential for:

• Bumpers

• Fender liners

• Battery casings

• Door trims

• Interior panels

Key properties include:

• Low thermal expansion

• Lightweight

• Chemical and weather resistance

• Excellent impact-to-stiffness balance

4. Fibers and Fabrics

PP is a dominant material in nonwoven and woven fabrics:

• Ropes and tapes

• Spunbond and meltblown fabrics

• Textile fibers for industrial and marine uses

5. Medical Applications

Thanks to its biocompatibility and chemical resistance, medical-grade PP is used for:

• Disposable syringes

• Petri dishes and lab containers

• IV bottles and medical vials

• Food-grade trays and containers

6. Industrial Uses

PP sheets and components are used for:

• Chemical tanks

• Industrial pipes

• RTP (Returnable Transport Packaging)

• Corrosive-resistant liners

7. Biaxially Oriented Polypropylene (BOPP) Film

BOPP is stretched in both directions for better:

• Strength and clarity

• Tear resistance

• Gloss and moisture barrier

• Dimensional stability

Processing Guidelines for PP Compounds

PP can be processed using most standard thermoplastic methods:

Injection Molding

• Melt temperature: 200–300°C

• Mold temperature: 10–80°C

• Drying: Not required under normal storage

• High mold temperature enhances surface finish

• Shrinkage rate: 1.5–3% (depending on thickness and conditions)

Extrusion

Used for pipes, films, cables, etc.

• Melt temperature: 200–300°C

• Compression ratio: 3:1

• Barrel temperature: 180–205°C

Other Processing Methods

• Compression molding

• Rotational molding

• Blow molding

• Extrusion blow molding

• Injection stretch blow molding