Abstract
Block copolymers and blends comprised by liquid crystalline oligoester and polystyrene were prepared and their thermal stability were characterized by thermogravimetric analysis (TGA). The samples have shown three main decomposition temperatures due to (1) lost of flexible chain and decomposition of mesogenic segment, (2) decomposition of polystyrene and (3) final decomposition of oligoester rigid segment. Both copolymers and polymer blends presented lower thermal stability compared to polystyrene and oligoester. The residual mass after heating at 600 °C in copolymers and polymer blends were lower than those found in the oligoesters. A degradative process of aromatic segments of oligoester induced by decomposition of polystyrene is suggested.
Highlights
The thermal behavior of liquid-crystalline polyesters acids are formed[11,12,13] (Figure 1)
The relative composition of the two polymeric segments in the block copolymers was determined by 1H-NMR spectrometry (Table 2)
A decrease of the Tg of the polystyrene phase in both polymeric systems, block copolymers and polymer blends, was observed and it is attributed to a partial miscibility of the oligoester in the polystyrene phase
Summary
The thermal behavior of liquid-crystalline polyesters acids are formed[11,12,13] (Figure 1). The thermal stability of a series of and engineering thermoplastics upon addition of a small copolymers comprised by polystyrene and liquid-crystalline. O O amount of liquid-crystalline polyester has been reported, even in the absence of miscibility in most of those systems[5,6]. Increased compatibility in polymer blends has been reported when a flexible liquid-crystalline polyester was employed and interfacial adhesion was observed[7,8]. The copolymers present liquid crystalline properties and a nematic mesophase is observed by polarizing optical microscopy and thermal analysis and they are distinguished by the following general chemical structure (Figure 2)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
