PBT examples of stress at yield retention versus temperature C

At low temperatures, the behaviour can be reasonably good down to -40°C or even -60°C according to the grades and the mechanical constraints undergone. 

Generally, notched Izod impact strengths slowly decrease between room temperature and -30°C. 

Glass transition temperatures are roughly 70°C for PETs, and 60°C for PBTs. 

These results relate to some grades only and cannot be generalized. 

Amorphous PET is transparent with light transmittance ranging from 80% up to 92%, haze of roughly 0.3-1.3% and a refractive index of about 1.575. Glass Polymers are specially designed to mimic thick glass for packaging cosmetics and healthcare products. 

---

Figure 4.69. PBT examples of stress at yield retention (%) versus temperature (°C)...

---