What Are the Differences Between PU and TPU?

When comparing PU vs TPU, it is clear that both polymers play an essential role in various industries because of their wide-ranging properties and applications. Short for Thermoplastic Polyurethanes, TPU is categorized as a thermoplastic elastomer having exceptional properties that surpass other thermoplastic elastomers. On the other hand, Polyurethanes (PU) encompasses a broader range of materials having diverse applications. Based on its structure, PU differs from other polymer materials and is named based on the present urethane linkages. There're many differences between both PU and TPU, including:

Raw Materials

TPU is made from different raw materials, including polyester or polyether for the soft segments or even polycaprolactones. These are the materials contributing to TPUs unique properties. On the other hand, PUs are manufactured by reacting polyester or polyether, among other polyols, with isocyanates. The final materials have different characteristics based on the polyol used.

PU vs TPU-Nature

TPU is primarily a thermoplastic material. It can be melted and reprocessed several times without undergoing sizeable chemical changes. On the other hand, many polyurethanes are thermosets. Thus, they undergo irreversible chemical changes when cured and can't be melted again. However, some PUs are thermoplastic, meaning you can melt and reprocess them.

TPU versus PU-Composition

Thermoplastic Polyurethanes consist of soft and hard segments within the molecular structure. These contribute to the TPU's versatility and unique properties. On the other hand, PUs have urethane linkages within their molecular systems formed through the reaction of isocyanates and polyols.

Elasticity and Flexibility

Because of its block copolymer structure, TPU exhibits excellent elasticity and flexibility. It can be bent and stretched repeatedly without any permanent, irreversible deformation. On the other hand, PUs can also exhibit a certain degree of flexibility based on their formulation. However, it doesn't have the same elasticity level as TPU.

Cross Links

The other aspect to consider when evaluating PU vs TPU is cross-links. To begin with, TPUs don't feature cross-links because their segmented block copolymer structures don't involve covalent bonding between their polymer chains. However, depending on the polyol used, PUs can have cross-links that form during the polymerization process. This usually results in a 3D network structure. These cross-links affect the dimensional stability and strength of the product formed using PUs.

Difference Between PUs and TPUs In Terms Of Application

PU is used in industries such as footwear, automotive, insulation, coating, and furniture. On the other hand, TPU is commonly used in making sportswear, footwear soles, industrial belts, electronic casings, and medical devices because of its exceptional durability, chemical resistance, and flexibility.

Processing

Polyurethane (PU) is available in different forms, such as films, coatings, adhesives, and foams. It can be processed through varying methods and techniques like extrusion, casting, and molding. On the other hand, TPU can be melted, shaped, and processed easily using techniques such as extrusion, blow molding, and injection molding, as it is a thermoplastic.

Take Away

Understanding the differences between PU vs TPU is the first step towards manufacturing quality products. This is because PU has very different properties than TPU, meaning they have various applications. Are you looking to purchase PU or TPU, or any other chemical? Look no further than Echemi.com. We sell quality chemicals sourced from quality manufacturers. We take all precautions to ensure the safe transportation of these chemicals, observing the highest professional standards.