What is TPE? Is TPE Safe?

The properties and characteristics of two separate groups are combined to form thermoplastic elastomers. These two groups are the followings.

1. Thermoplastics (Upon heating these will melt and can also be molded)
2. Elastomers (They shows elastic characteristics)

Moreover; these materials show the elastic properties similar to the rubber materials. This combination of properties is of important consideration because it enables these materials to be processed through numerous methods including extrusion, blow molding and injection molding. In this way these materials are manufactured effectively and efficiently.

The Structure of TPE (Basics)

Generally, there are three segments of the basic structure of thermoplastic elastomers.

1. Structure of Block Copolymer
2. Separation of the micro phase

• Crystalline and amorphous portion

1. Block Copolymer Structure:

In general, thermoplastic elastomers are comprised of two different kinds of segments. These two segments or blocks are termed as hard segments and soft segments.

Hard segments: The hard segments of TPE provides basis for the mechanical properties of TPE. Consequently, these segments offer strength and stiffness to the thermoplastic elastomers. The hard segments of TPE are normally composed of thermoplastic blocks. These thermoplastic blocks have crystalline or glassy structure.

Soft Segments: The soft segments of TPE material give the basis to provide elastic characteristics to the thermoplastic elastomers. The major properties and characteristics provided by these segments include followings.

1. Elasticity
2. Flexibility

The properties are governed by the rubber material present in the soft segments. The basic constituents are the followings.

• Ethylene propylene
• Polyethylene
• Polypropylene

2. Separation Of the Microphase

The structure of thermoplastic elastomers at the microscopic level is of significant importance. The basic portions of TPE which are hard segments and soft segments have the tendency to lose joining at microscopic scale. The separation of these segments is crucial to characteristics and properties of the thermoplastic elastomers. The mechanical properties of TPE are directly affected by this separation. The thermoplastic phase of TPE ensures the structural integrity while the rubbery phase upholds the elastic nature of TPE. Subsequently the variation in mechanical characteristics of TPE including hardness, tensile strength and elongation is controlled by the nature and extent of separation of the microphase.

• Crystalline And Amorphous Portion

There are two portions of hard segments of TPE. These portions are termed as crystalline and amorphous region. In order to achieve the required characteristics and properties these regions of hard segments of TPEs are tailored during the manufacturing process. The crystalline portion offers properties of strength and rigidity while amorphous portion gives characteristics of impact resistance and flexibility. 

The Prime Question, Is TPE Safe?

Thermoplastic elastomers possess unique characteristics and they can be easily processed for manufacturing. Because of these advantages, utilization of TPEs has been increased in various sectors and industries. Consequently, by the expansion of the utilization of TPEs, the question regarding the safe usage of thermoplastic elastomers arises.

Generally, if thermoplastic elastomers are being utilized in appropriate manner and not violating the regulatory standards, they are considered safe. So TPE is safe to be used in numerous applications because they are engineered in such a way that they do not contain any harmful substance and are nontoxic as well. However, some perceptions are there which consider that thermoplastic elastomers are not safe to be used in certain contexts. go to TPE injection molding page to know more.

Potential Concerns Regarding Usage of TPEs

Followings are the potential concerns which need to be addressed regarding utilization of thermoplastic elastomers.

1. Biocompatibility

Thermoplastic elastomers are readily utilized in medical sector and food industry. In food industry TPEs are used for manufacturing of food containers while in medical sector they are utilized to produce various medical implants and to form pharmaceutical packaging. Keeping in view the sensitivity of these utilizations, some specific biocompatibility test of TPEs must be carried out prior to their usage in such vital areas. These certain tests will ensure that thermoplastic elastomers will not release any harmful substances inside the body when subjected to utilization. Following two parameters need to be carried out carefully to ensure that TPEs are safe:

• Proper formulation
• Adequate testing for biocompatibility
• Chemical Additives

This parameter is of significant importance regarding the safety of thermoplastic elastomers. This concern is related to the formulation of the TPEs which may pose risks if not properly checked and tested as per regulatory limits. Following chemical additives are included in certain thermoplastic elastomers mainly to uplift their characteristics.

• Stabilizers
• Flame retardants
• Plasticizers

It is pertinent to mention that certain flame retardants and plasticizers tends to disrupt the hormones. Mainly phthalates and brominated compounds are included in this category. The adverse effects of these chemicals are directly related to the health concerns. It is important to eliminate the risks which are posed to human health by these chemical additives utilized in thermoplastic elastomers. Keeping that in view the role of manufacturers is very important in this context because they to ensure at all costs that chemical additives being utilized in TPEs are in full compliance with safety standards and regulatory limits.

2. Recycling of TPEs (A process full of challenges)

There are numerous challenges which are to be faced and overcome during the recycling of TPEs. This is because of these two main reasons.

1. Chemical additives used in TPEs
2. Numerous kinds of formulations

Generally, the quality of recycled thermoplastic elastomers is inferior as compared to new manufactured TPEs. This is because of the mixed plastics which are also contaminated as well most of the times. Consequently, these low quality TPEs cannot be utilized in certain applications and ultimately this leads to waste management problems.

3. Environmental Impact

There are two types of sources from which thermoplastic elastomers are derived.

1. Bio based sources
2. Petroleum based sources

The processing and cultivation of TPEs which are bio-based need energy, water and land. However, these are less relied on fossil fuels. While the processing and extraction of TPEs which are petroleum based provides contribution in greenhouse gas emission and consumption of fossil fuel. Thermoplastic elastomers are recyclable, lightweight and provide significant energy efficiency during processing. Because of these characteristics TPEs are more environment friendly as compared many other materials.

Although, TPEs offer many soft corners for environment it may have some adverse effects on the environment as well. This happens usually because of the improper disposal of the thermoplastic elastomers. This is of significance importance because thermoplastic elastomers can contain following harmful substances.

• Chemical additives
• Contaminations

Consequently, improper disposal of TPEs will result into environmental pollution.

Misconceptions Regarding Safety of TPEs

There are some misconceptions as well which leads to the creation of the perception that thermoplastic elastomers are not safe. These misunderstandings are quite different from the actual concerns. These misconceptions are as follows.

1. Lack of Awareness and Outdated Information

The important factor to create the perception that thermoplastic elastomer is safe or not is awareness. This awareness includes following two important parameters.

1. The knowledge of specific kind of TPEs being utilized in various products and items
2. The understanding of rules and regulatory standards which are in place and re being implemented to ensure the safety of thermoplastic elastomers

So, subsequently lack of awareness of the above-mentioned parameters will lead to the misconception that thermoplastic elastomers are not safe. Moreover, there is continuous advancement in the fields of polymer chemistry and material science. This advancement is leading towards the enhanced and improved safety profiles of thermoplastic elastomers. It is important to base the perception about the safety of TPEs on updated and authentic information. Because, misinformation or outdated information will ultimately produce misconceptions regarding safety of thermoplastic elastomers and mistrust about plastic materials.

2. Confusion with Other Materials Which Release Harmful Substances

Most of the times, thermoplastic elastomers are confused with other materials which release harmful substances. This confusion normally arises between TPEs and following two materials.

1. Thermoset plastics
2. Thermoplastic Polyurethane

Confusion with Thermoset Plastics

Thermoset plastics tend to emit harmful and dangerous substances during the following processes.

• Production process
• Degradation process

Thermoset plastics differ from TPEs due to followings:

3. Thermoset plastics shows irreversible chemical reactions
4. Re melting and reshaping cannot be done

While on the other hand thermoplastic elastomers show the quite opposite behavior.

Confusion with Thermoplastic Polyurethane

The addition of diisocyanate with polyol chemical additives will lead to the production of thermoplastic polyurethane. TPU is created which provides the following characteristics and properties.

• Elasticity and shape memory
• Resilience and Flexibility
• High toughness
• Good impact resistance
• Enhanced durability
• Excellent resistance to Oil and other contaminations
• Resistance to extreme weather conditions

Thermoplastic Polyurethane tends to emit certain chemicals based on the following factors.

• Formulation and composition of thermoplastic Polyurethane
• Type and nature of chemical additives

The dangerous and harmful materials released by the thermoplastic Polyurethane includes the followings.

• Flame retardants
• Plasticizers
• Stabilizers

These chemicals pose potential threat to human life if they are released in the open environment and then inhaled or ingested. Go to TPU injection molding page to know more about TPU.

Confusion with Poly Vinyl Chloride

PVC tends to emit dangerous materials when some typical conditions exist.

These conditions can exist during the following stages.

• During the production of PVC
• During the utilization of PVC
• During the disposal of PVC

PVC is often confused with thermoplastic elastomers. This confusion is mostly based because of the unawareness of the following parameters.

• Safety profiles of the materials
• Chemical composition of the material
• Impact of the material on the environment

The detailed comparison and explanation is presented below to elaborate the difference between PVC and TPEs and how the confusion arises.

Comparison with Thermoplastic Polyurethane, Thermoplastic Elastomers and Thermoplastic Polyurethane

The detailed comparison how thermoplastic elastomers differ from thermoplastic polyurethane is presented below.

Comparative Data of PVC, TPU, and TPEs

CONCLUSION

Thermoplastic elastomers proved to have versatile characteristics and found their utilization in many important areas. Generally, TPEs are considered safe to be utilized in numerous applications when their manufacturing is carried out in a proper way. The concerns which need to be addressed regarding the safety of the thermoplastic elastomers include their biocompatibility, challenges faced during their recycling, their impact on the environment and nature of the chemicals being added in TPEs. These concerns can be effectively addressed by ensuring the correct and transparent formulation of the product, by adhering to standards established by regulatory bodies and by carrying out proper waste management.

Thermoplastic elastomers are being extensively utilized in food industry, consumer goods and medical sector. Among these entire medical sectors is most important because it involves the sensitive factor of the human health. These applications are using thermoplastic elastomers considering its non-toxic nature. The advance research and development are focused on making the thermoplastic elastomers safer along with enhanced mechanical characteristics and properties. This will ultimately broaden the scope of TPEs applications by ensuring its safety.