Effects of a trans- or cis-cyclohexane unit on the thermal and rheological properties of semi-aromatic polyamides. Issue 1 (18th November 2015)

• Record Type: Journal Article
• Authors: Zhang, Gang; Yan, Guang-Ming; Ren, Hao-Hao; Li, Yan; Wang, Xiao-Jun; Yang, Jie
• Is Part Of: Polymer chemistry. Volume 7:Issue 1(2016)
• Page Start: 44
• Page End: 53
• Publication Date: 2015-11-18
• Subjects: Polymers -- Periodicals; Macromolecules -- Periodicals; Polymerization -- Periodicals; 547.705
• DOI: 10.1039/c5py01634g
• Languages: English
• ISSNs: 1759-9954

Abstract

Abstract : Polyamides containing trans -formation cyclohexane unit was found to have better physical performance than that of sample with cis -formation such as mechanical, thermal and oxidation resistance properties etc. Abstract : Semi-aromatic monomers containing a cyclohexane unit, prepared using a facile interfacial reaction method from 1, 4-cyclohexanediamine ( tran s- or cis -) and 4-fluorobenzoyl chloride (4-FBC) at room temperature, were reacted with 1, 1-bis(4-hydroxyphenyl)-1-phenylethane (BHPPE) to afford two kinds of semi-aromatic polyamide (BH- trans -BFCD and BH- cis -BFCD) in this work. An investigation of thermal properties confirmed high glass transition temperatures ( T g ) of 224–265 °C and good thermal stability with initial degradation temperatures ( T d ) of 445 to 450 °C for the synthesized semi-aromatic polyamides, which were determined by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) characterization. It was found that the properties (thermal and mechanical) of BH- trans -BFCD, containing a trans -conformation, were much better than those of BH- cis -BFCD, containing a cis -conformation. Comparing the thermal stability of the resultant semi-aromatic polyamides with a commercial product, PA6T-Dupont, the prepared polyamides treated at 220 °C for 7 h displayed a slightly reduced tensile strength as well as a smaller change in color. According to rheological testing, they were found to have better melt flowability (complex viscosities ranged from 210 to 3070 Pa s at 310 °C to 360 °C). Additionally, their thermal degradation kinetics and the thermal pyrolysis mechanism of these semi-aromatic polyamides were investigated by thermogravimetric analysis and Pyrolysis/Gas Chromatography/Mass (Py-GC/MS) analysis, which further indicated their higher thermal stability and processability.