Synthesis, processing and performance analysis of thermoplastic polyurethane elastomer TPU

What is polyurethane TPU?

Thermoplastic polyurethaneTPU is a type of polyurethane that can be plasticized by heating and dissolved by solvents. Compared with mixing and casting polyurethane, thermoplastic polyurethane has no or very few chemical crosslinks in its chemical structure. Its molecules are basically linear, but there is a certain amount of physical exchange.

The concept of so-called physical exchange was first proposed by Schollenberge C.S. in 1958. It refers to the existence of heat or solvent between linear polyurethane molecular chains. Reversible “junction point”, which is not actually a chemical cross-link, but functions as a chemical cross-link. Due to this physical cross-linking, polyurethane forms a multi-phase morphological structure theory. The hydrogen bonds of polyurethane strengthen its morphology and make it resistant to higher humidity.

What are the classifications of polyurethane TPU?

Now that you know itThermoplastic polyurethaneWhat is TPU, and what are its classifications? According to different classification standards, TPU can be classified into many different categories.

For example, press The soft segment structure can be divided into polyester type, polyether type and butadiene type, which contain ester group, ether group or butenyl group respectively. According to the hard segment structure, it is divided into urethane type and carbamate urea type, which are obtained by glycol chain extender or diamine chain extender respectively.

Commonly common It is divided into polyester type and polyether type.

Click yes or no Cross-linking can be divided into pure thermoplastic and semi-thermoplastic. The former is a pure linear structure with no cross-linking bonds; the latter contains a small amount of cross-linking bonds such as allophanate. According to the use of finished products, they can be divided into special-shaped parts (various mechanical parts), pipes (sheaths, rod profiles) and films (sheets, thin plates), as well as adhesives, coatings and fibers.

How is polyurethane TPU synthesized?

Thermoplastic polyurethaneAlthough there are many classifications of TPU, in terms of molecular structure, they are all Belongs to polyurethane. So, how does it come together?

Since the hardness ofTPU can be adjusted by adjusting the ratio of soft and hard segments, TPU has a relatively wide hardness range, and its hardness ranges from Shore 60A- -80D, spans the hardness of rubber and plastic, and is highly elastic throughout the hardness range.

As the hardness changes, some properties of TPU will change. For example, increasing the hardness of TPU will result in performance changes such as increased tensile modulus and tear strength, increased rigidity and compressive stress (load capacity), reduced elongation, increased density and dynamic heat generation, and increased environmental resistance.

In what fields is polyurethane TPU used?

The current global production of polyurethaneTPU raw material manufacturers mainly include: BASF, original German imports, Lubrizol, Huntsman, McKinsey, Gaoding, etc.

As an elastomer with excellent performance,PolyurethaneTPU has a wide range of downstream product directions and is widely used in daily necessities, sporting goods, toys, decorative materials and other fields. The following Give a few examples.

①. Shoe materials

TPU is used The shoe material is mainly due to its excellent elasticity and wear resistance. Footwear products containing elastomer TPU are much superior to ordinary footwear products in terms of wearing comfort. Therefore, they are widely used in high-end footwear products, especially some sports shoes and casual shoes.

②. Hose

Because TPU hose has softness, good tensile strength, impact strength and high and low temperature resistance, so TPU hose is widely used in aircraft, tanks, Gas and oil transmission hoses for automobiles, motorcycles, machine tools and other mechanical equipment.

③. Cable

Polyurethane elastomer TPU provides tear resistance, wear resistance and bending characteristics, and high and low temperature resistance is the key to cable performance. Therefore, in the Chinese market, TPU is used for high-end cables such as control cables and power cables. It is used to protect the coating materials of complexly designed cables, and its uses are becoming increasingly widespread.

④. Medical equipment

TPU is a This is a safe, stable and high-quality PVC alternative material that does not contain harmful chemical substances such as phthalates, which can migrate into the blood or other liquids in medical catheters or medical bags and cause side effects. The specially developed extrusion grade and Injection molding grade TPU can be easily used with just a little debugging on existing PVC equipment.

TPU for cables is a coating material used to protect cables with complex designs, and its uses are becoming increasingly widespread.

④. Medical equipment

TPU is a This is a safe, stable and high-quality PVC alternative material that does not contain harmful chemical substances such as phthalates, which can migrate into the blood or other liquids in medical catheters or medical bags and cause side effects. The specially developed extrusion grade and Injection molding grade TPU can be easily used with just a little debugging on existing PVC equipment.