We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Temperature-Controlled Chain Dynamics in Polyimide Doped with CoCl 2 Probed Using Dynamic Mechanical Analysis.
- Authors
Ionita, Daniela; Cristea, Mariana; Sava, Ion; Popescu, Maria-Cristina; Dobromir, Marius; Simionescu, Bogdan C.
- Abstract
Cobalt(II) chloride (CoCl2) being in the vicinity of polyimide chains entails modifications in terms of the molecular dynamics, which are mainly governed by the possible presence of amic acid residual groups, by the transition-metal-type characteristics of cobalt and by the CoCl2 content. Polyimide was synthesized using poly(amic acid) according to the reaction of 2,2′-bis(3,4-dicarboxylphenyl)hexafluoropropane dianhydride (6FDA) with 3,3′-dimethyl-4,4′-diaminodiphenylmethane (MMDA) in N,N-dimethylacetamide. CoCl2 was added before the thermal imidization of the poly(amic acid). An experimental approach was designed to establish the interaction between the polyimide and CoCl2 and whether the interaction depends on the quantity of the salt. Evidence for the existence of residual amic acid groups was obtained using second derivative Fourier Transform Infrared Spectroscopy (FTIR) and with the help of 2D correlation spectroscopy (2D-COS). Moreover, FTIR, along with X-ray photoelectron spectroscopy (XPS), revealed the interaction between the polymer and CoCl2, primarily in the form of Co(II)-N coordinated bonds. Nevertheless, the coordination of cobalt with suitable atoms from the amic acid groups is not precluded. The results of dynamic mechanical analysis (DMA) featured a specific relaxation assigned to the presence of CoCl2 in the polymeric film and demonstrated that its (non)reinforcing effect depends on its content in the polyimide.
- Subjects
DYNAMIC mechanical analysis; POLYIMIDES; FOURIER transform infrared spectroscopy; AMIC acids; X-ray photoelectron spectroscopy; COORDINATE covalent bond
- Publication
Materials (1996-1944), 2024, Vol 17, Issue 3, p753
- ISSN
1996-1944
- Publication type
Article
- DOI
10.3390/ma17030753