TPU is an important component of car paint protective film. It can provide good light transmission and toughness, and is a solid barrier to prevent car paint from being scratched and damaged. However, TPU is also divided into many varieties.
Commonly used polyols for the synthesis of TPU are: polyester polyols, polyether polyols, polycarbonate polyols, polycaprolactone polyols, etc.
1. Polyester type and polycarbonate type
Due to the existence of easily hydrolyzed ester groups, polyester TPU is vulnerable to the attack of water molecules and the molecular chain breaks, and the acid generated by hydrolysis can catalyze the further hydrolysis of polyester. The water resistance of polyester TPU is relatively poor, and the cost is relatively low. relatively low.
2. Polyether type
Polyether-type TPU, because the ether group of the soft segment is easier to rotate, has better flexibility and superior low-temperature performance, and there is no ester group that is relatively easy to hydrolyze in the polyether, and its hydrolysis resistance is better than that of the polyether type. However, the mechanical strength, oil resistance and heat resistance are relatively poor.
3. Polycaprolactone type
Polycaprolactone TPU is between polyester and polyether, with good comprehensive performance, excellent mechanical strength, oil resistance, chemical resistance, wear resistance and tear resistance, good flexibility, superior Excellent low temperature performance, and there is no ester group that is relatively easy to hydrolyze, and its hydrolysis resistance is good.
To sum up, aliphatic polycaprolactone TPU is the first choice for a good car paint protective film.
Distinguishing method
The advantages and disadvantages of car paint protective film can be distinguished from its material characteristics.
The most common thing is to look at the light transmittance of the material, whether there are any impurities, and then judge by the feel. TPU material feels very soft, and it is slightly elastic when pressed, while inferior car paint protective films are generally hard .
Secondly, it can be judged from the taste and stretching degree that the car paint protection film made of TPU is generally tasteless and has better stretchability, while the poor-quality car paint protection film is the opposite, and the smell is obvious or even pungent. , and its stretching range is also small.
Finally, it can be distinguished by observing its burning state. PVC or TPH car paint protective film will have black smoke after being ignited, and the smell of burning plastic is more obvious, while TPU material is the opposite.
Of course, in order not to step on the pit, car owners should try their best to choose a car paint protective film brand with guaranteed quality, and the real materials can be traced back to the source.