Properties of heat

a. The relationship between thermal deformation temperature and load

TPX release film Tg value is only 10-30 ℃, and under high load, its thermal deformation temperature (HDT) is relatively low. However, due to the melting point (Tm) reaching 220-240 ℃, it has HDT under low or no load. The softening point of Vicat is 140-180 ℃, which is equivalent to PC or PSu.

b. Heat resistance life

The thermal life of TPX release film is determined by temperature and time. Aging in the air is caused by oxidation reactions. To prevent oxidation reactions, heat-resistant stabilizers can be added, which can extend the heat-resistant life by about three times. The temperature index of UL specification (UL 946B) is 115 ℃, which belongs to UL94 HB level.

Other properties

a. Optical properties

The TPX release film has a high light transmittance in the range from ultraviolet to infrared. The wavelength of ultraviolet light can be analyzed and utilized for oxygen or chemical components in blood and liquids. TPX is one of the few materials with drug resistance and good UV transmittance. The refractive index of light is very low, only 1463, second only to fluorine resin at 1.338-1.425.

b. Breathability

TPX release film has high breathability and selectivity, which is one of its characteristics due to its low density and non polarity. The permeability to oxygen is 4-6 times that of nitrogen, so it can be used as an oxygen rich membrane.

c. Drug resistance

TPX release membrane is a kind of polyene, so it has excellent drug resistance. It is also free from Mineral acid and inorganic base at high temperature, and can resist a variety of organic solvents. It does not decompose in high temperature and high pressure steam, maintaining considerable mechanical strength. The organic solvents that can degrade and swell are aromatic solvents such as benzene, toluene, cyclohexanone, and chlorinated solvents such as Trichloroethylene, carbon tetrachloride, and chloroform. PC, PMMA, PSU, etc. will crack in MEK and MIBK due to residual internal stress, while TPX release film will not.

d. Electrical characteristics

When TPX release film is used as an electrical insulation material, its advantages include good heat resistance, high insulation failure voltage, low dielectric constant, and positive dielectric connection. Its disadvantages include insufficient elongation at low temperatures and poor copper resistance (easily promoted by copper ions for decomposition). The method to improve low-temperature characteristics is to mix with low molecular weight oligomers, and adding copper hazard prevention agents can improve copper resistance. The dielectric loss of TPX release film is the smallest among insulation materials, approximately the same as PE and fluororesin. The peak dielectric loss at 60-120 ℃ can be shifted by the addition of oligomers or mixing with other resins and inorganic substances.

e. Weather resistance

The TPX release film has tertiary carbon atoms in its molecular structure, making it susceptible to degradation by ultraviolet radiation. However, the addition of ultraviolet absorbers can improve its post harvest resistance, and the improved TPX still has transparency.