DOP (Dioctyl Phthalate) and DOTP (Dioctyl Terephthalate) are both colorless, oily liquids used as primary plasticizers for PVC plastics. While they share similar molecular structures and weights, as well as nearly identical specific gravities, there are notable differences in their properties and applications due to their distinct structural forms. DOTP features a linear symmetric structure, while DOP has a spherical structure, resulting in the following differences:
1. Plasticizing Efficiency: DOP has a slightly higher plasticizing performance compared to DOTP, offering broader practicality in various applications.
2. Electrical Performance: DOTP outperforms DOP in electrical properties, boasting a volume resistivity 20 times greater than that of DOP. This makes DOTP more suitable for electrical applications.
3. Heat Resistance: DOTP has a flash point 10°C higher than DOP, contributing to more stable electrical performance after heating. Under identical conditions, DOTP exhibits only half the residual volatile content of DOP, making it ideal for manufacturing high-temperature resistant PVC cable materials.
4. Cost: DOTP tends to be slightly more expensive than DOP.
5. Cold Resistance: DOTP shows significantly better cold resistance than DOP, although it is slightly less effective than DOA and DOS. Despite this, DOTP is considerably more affordable than DOA and DOS. Its superior low-temperature flexibility and resistance make DOTP a preferred choice for automotive, refrigerator, and window sealing strips, contributing to cost savings.
6. Environmental Friendliness: Inhaling small amounts of DOP can lead to shortness of breath, increased heart rate, central nervous system disorders, and gastrointestinal discomfort. Severe exposure can impact fetal development, causing deformities. As a result, European and American countries have imposed strict regulations on the use of DOP plasticizers. DOTP, on the other hand, fully complies with EU RoHS and US SGS environmental requirements, making it a safer alternative.