1. Understanding the Basics of the IAPD Thermoplastics Rectangle
Plastic Materials and
the IAPD Thermoplastics Rectangle
Prepared by the IAPD Education Committee (Module 2)
Presented courtesy of Modern Plastics, Inc.
The IAPD Plastics Primer, Module 2

2. The IAPD Plastics Primer, Module 2
The intent of this module is to give you a general understanding of thermoplastics and
thermosets. We also hope to give you a good understanding of the general groups of materials in the Thermoplastics Rectangle.
This will give you a broad understanding of each family of plastics to help you offer materials that meet a customers’ set of requirements. In subsequent sections we will go into each material in further depth.
The IAPD Plastics Primer, Module 2

3. Definitions Thermoplastic Thermoset The IAPD Plastics Primer, Module 2
A thermoplastic can be melted and shaped several times. The thermoplastic materials are either crystalline or amorphous. A thermoplastic can be compared to wax and
ice — those materials can be hardened and formed into other shapes.
A thermoset plastic is a polymeric material that can be formed by application of heat and pressure, but can not be reformed upon further applications of heat and pressure.
A thermoset is like a cooked egg and can not be re-melted and reshaped into another solid shape.
A thermoplastic can be compared to wax and ice — those materials can be hardened and formed into other shapes.
We’ll discuss thermoplastics throughout most of the modules, thermosets will be covered in the last module.
The IAPD Plastics Primer, Module 2

4. Types of Thermoplastics
Imidized materials
Amorphous plastics
High performance
Engineering
Commodity
Semi-crystalline plastics
There are three types of thermoplastics: imidized, amorphous and semi-crystalline.
Polymers are often described as being either crystalline or amorphous when it is actually more accurate to describe plastics by their “degree of crystallinity.” Polymers cannot be 100 percent crystalline otherwise they would not be able to melt due to the highly organized structure. Therefore, most polymers are considered semi-crystalline materials with a maximum of 80 percent crystallinity.
Amorphous materials have no patterned order between the molecules and can be likened to a bowl of wet spaghetti. Amorphous materials include atactic polymers since the molecular structure does not generally result in crystallization.
Amorphous and semi-crystalline thermoplastics may be divided into three categories: high performance, engineering and commodity. We will go through each of these in more detail.
The IAPD Plastics Primer, Module 2

5. Amorphous vs. Crystalline Thermoplastics
Amorphous (a-morphous = without shape) - The polymer chains are in random arrangement. Molecular structure is incapable of forming regular order (crystallizing) with molecules or portions of molecules regularly stacked in crystal-like fashion. Molecular arrangement is randomly twisted, kinked and coiled.
Crystalline - The polymer chains form a regular pattern. Molecular structure forms regular order (crystals) with molecules or portions of molecules regularly stacked in crystal-like fashion. Molecular arrangement is arranged in an ordered fashion.
By understanding what area specific materials fall into, you can develop a broad understanding of their properties in the virgin state. However, by modifying some materials with fillers and other chemical additives, you may see these properties created overlap into other categories.
The IAPD Plastics Primer, Module 2

6. Amorphous Commodity Thermoplastics Key Characteristics
Low cost, temperature resistance and strength
Good dimensional stability
Bonds well
Typically, but not always, transparent
These are the key characteristics of amorphous commodity thermoplastics.
The IAPD Plastics Primer, Module 2

7. Amorphous Commodity Thermoplastics Materials
Acrylic (PMMA)
Polystyrene (PS)
Acrylonitrile - Butadiene - Styrene (ABS)
Polyvinyl Chloride (PVC)
Polyethylene Terepthalate Glycol (PETG)
Cellulose Acetate Butyrate (CAB)
The IAPD Plastics Primer, Module 2

8. Amorphous Engineering Thermoplastics Key Characteristics
Moderate cost
Moderate temperature resistance
Moderate strength
Good to excellent impact resistance
Good dimensional stability
Not true in all cases:
Translucency
These are the key characteristics of amorphous engineering thermoplastics.
For special cases, not all cases, there is good optical quality and some translucency.
Translucency means that you can see through the material, but not well.
The IAPD Plastics Primer, Module 2

9. Amorphous Engineering Thermoplastics Materials
Polycarbonate (PC)
Polyphenylene Oxide (Modified PPO)
Polyphenylene Ether (Modified PPE)
Thermoplastic Urethane (TPU)
The IAPD Plastics Primer, Module 2

10. Amorphous High Performance Thermoplastics Key Characteristics
High cost
High temperature
High strength and good stiffness
Good chemical resistance
Transparency
Hot water and steam resistance
These are the key characteristics of amorphous high performance thermoplastics.
The IAPD Plastics Primer, Module 2

11. Amorphous High Performance Thermoplastics Materials
Polysulfone (PS)
Polyetherimide (PEI)
Polyethersulfone (PES)
Polyarylsulfone (PAS)
The IAPD Plastics Primer, Module 2

12. Semi-Crystalline Commodity Thermoplastics Key Characteristics
Low cost, temperature resistance and strength
Excellent chemical resistance
Low COF
Near zero moisture absorption
Very good electrical properties
Good toughness
These are the characteristics of semi-crystalline commodity thermoplastics.
The IAPD Plastics Primer, Module 2

13. Semi-Crystalline Commodity Thermoplastics Materials
Polyethylene (PE)
High Density Polyethylene (HDPE)
Low Density Polyethylene (LDPE)
Polypropylene (PP)
Polymethylpentene (PMP)
The IAPD Plastics Primer, Module 2

14. Semi-Crystalline Engineering Thermoplastics Key Characteristics
Moderate cost, temperature resistance and strength
Good chemical resistance
Good bearing and wear properties
Low COF
Difficult to bond
These are the key characteristics of semi-crystalline engineering thermoplastics.
The IAPD Plastics Primer, Module 2

15. Semi-Crystalline Engineering Thermoplastics Materials
Nylon (PA)
Acetal (POM)
Polyethylene Terepthalate (PET)
Polybutylene Terepthalate (PBT)
Ultra High Molecular Weight Polyethylene (UHMW-PE)
The IAPD Plastics Primer, Module 2

16. Semi-Crystalline High Performance Thermoplastics Key Characteristics
Temperature resistance
Good electrical properties and toughness
Outstanding chemical resistance
Low coefficient of friction (COF)
High cost
These are the key characteristics of semi-crystalline high performance thermoplastics.
The IAPD Plastics Primer, Module 2

17. Semi-Crystalline High Performance Thermoplastics Materials
Polyvinylidene Fluoride (PVDF)
Polytetra Fluoroethylene (PTFE)
Ethylene-chlorotrifluoroethylene (ECTFE)
Fluorinated Ethylene Propylene (FEP)
Polychlorotrifluoroethylene (PCTFE)
Perfluoroalkoxy (PFA)
Polyphenylene Sulfide (PPS)
Polyetheretherketone (PEEK)
These are the various materials under semi-crystalline high performance thermoplastics.
Common trade names for PVDF are Kynar and Solef.
A common trade name for ECTFE is Halar.
Common trade names for PPS are Ryton and Fortron.
The IAPD Plastics Primer, Module 2

18. Imidized Materials Key Characteristics
Very high cost per pound
Excellent properties above 204°C/400°F
Excellent electrical properties
Excellent dimensional stability
Low coefficient of friction (COF)
Very low thermal expansion
Good wear characteristics
Imidized materials are used in the most demanding applications. This is due to the fact that they display many of the properties of both amorphous and crystalline thermoplastics.
The IAPD Plastics Primer, Module 2

19. Imidized Materials Materials
Polyimide (PI)
Polyamide-imide (PAI)
Polybenzimidazole (PBI)
Common trade names for:
PI = Vespel, Duratron and Sintimid
PAI = Torlon
PBI = Celazole .
The IAPD Plastics Primer, Module 2

20. The IAPD Plastics Primer, Module 2
We hope you have a good basic understanding of the material categories now and where they fall in the IAPD Thermoplastics Rectangle.
In future modules we will go into each section and material, how they are made, applications, and products produced from the materials.
The IAPD Plastics Primer, Module 2