Preparation of semi-interpenetrating networks of phthalonitrile and polyetherimide resin: study of their curing characteristics and thermal properties

• Published in: Journal of thermal analysis and calorimetry Vol. 148; no. 10; pp. 4171 - 4183
• Main Authors: Singh, A. S., Banshiwal, J. K., Mishra, Preeti, Shukla, S. K., Bag, D. S., Tripathi, D. N.
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01-05-2023; Springer; Springer Nature B.V
• Subjects: Analysis; Analytical Chemistry; Calorimetry; Chemistry; Chemistry and Materials Science; Composition; Curing; Dynamic loads; Dynamic mechanical analysis; Dynamic stability; Enthalpy; Fourier transforms; Glass transition temperature; High temperature; Infrared spectroscopy; Inorganic Chemistry; Interpenetrating networks; Measurement Science and Instrumentation; Medical research; Medicine, Experimental; Physical Chemistry; Physical properties; Polyetherimide; Polyetherimides; Polymer Sciences; Stability analysis; Stoichiometry; Storage modulus; Thermal properties; Thermal stability; Thermodynamic properties; Thermoplastic resins; Thermosetting resins; Phthalonitrile; Semi-interpenetrating network; Polyether imide; Glass transition temperature; Thermo-mechanical properties
• ISSN: 1388-6150; 1588-2926
• DOI: 10.1007/s10973-023-12042-2

Present embodiment is an account of work done on impregnation of thermoplastic polyether imide (PEI) [ULTEM 1000] into high-temperature biphenyl-based phthalonitrile (PN) thermosetting resin to form a semi-interpenetrating network (s-IPN) in order to find an optimum composition with little compromise on glass transition temperature (
T
g) and thermal stability of base resin system. The PEI has been cured with PN resin in varied ratios of 5–30 mass% in arithmetic progression to study its effect on thermal and physical properties. Fourier transform infrared spectroscopy, differential scanning calorimetry and thermos-gravimetric (TG) measurements of the s-IPN compositions were carried out to assess the extent of curing, curing enthalpy, glass transition (
T
g)
, thermal stability and char yield, respectively. The dynamic mechanical analysis (DMA), measurements were done to ascertain the effect of PEI component in PN system on its storage modulus,
T
g
under dynamic load with respect to temperature. PN95 composition having PN/PEI ratio in 95:05 stoichiometry has demonstrated the best desirable properties with respect to PEI content with least compromise in
T
g temperature. More than 5 mass% PEI has resulted in drastic change in
T
g
of s-IPN from > 673 K to 525 K in case of 10 mass% PEI as evaluated by DMA. The morphological analysis of 30% PEI-containing s-IPN showed interesting cross-linked patterns probably formed by the fibrillar orientation of the thermoplastic resin in the PN matrix.