Synthesis of novel tri‐benzoxazine and effect of phenolic nucleophiles on its ring‐opening polymerization. Issue 17 (18th June 2016)

• Record Type: Journal Article
• Authors: Nalakathu Kolanadiyil, Sini; Azechi, Motohisa; Endo, Takeshi
• Is Part Of: Journal of polymer science. Volume 54:Issue 17(2016)
• Page Start: 2811
• Page End: 2819
• Publication Date: 2016-06-18
• Subjects: benzoxazine -- thermosets -- phenolic modifiers -- ring-opening polymerization -- degradation; 547
• DOI: 10.1002/pola.28167
• Languages: English
• ISSNs: 0887-624X

Abstract

ABSTRACT: A trifunctional benzoxazine, 1, 3, 5‐tris(3‐phenyl‐3, 4‐dihydro‐2H‐benzo[1, 3]oxazin‐6‐yl)benzene (T‐Bz) was synthesized and in an effort to reduce its curing temperature (curing maxima at 238 °C), it was mixed with various phenolic nucleophiles such as phenol (PH), p ‐methoxy phenol (MPH), 2‐methyl resorcinol (MR), hydroquinone (HQ), pyrogallol (PG), 2‐naphthol (NPH), 2, 7‐dihydroxy naphthalene (DHN), and 1, 1'‐bi‐2‐naphthol (BINOL). The influence of these phenolic nucleophiles on ring‐opening polymerization temperature of T‐Bz was examined by DSC and FTIR analysis. T‐Bz undergoes a complete ring‐opening addition reaction in the presence of bi‐ and trifunctional phenolic nucleophiles (MR/HQ/PG/DHN) at 140 °C (heated for 3 h) and forms a networked polybenzoxazine (NPBz). The NPBzs showed a high thermal stability with T d20 of 350–465 °C and char yield of 67–78% at 500 °C; however, a diminutive weight loss (6.9–9.8%) was observed at 150–250 °C ( T d5 : 215–235 °C) due to degradation of phenolic end groups. This article also gives an insight on how the traces of phenolic impurities can alter the thermal properties of pure benzoxazine monomer as well as its corresponding polymer. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem.2016, 54, 2811–2819 Abstract : The influence of various phenolic nucleophiles on ring‐opening polymerization of a trifunctional benzoxazine monomer (T‐Bz) was studied and a complete ring‐opening of tri‐oxazine was observed in the presence of phenolic nucleophiles such as MR, hydroquinone, pyrogallol, and 2, 7‐dihydroxy naphthalene at a very low temperature. The obtained networked polybenzoxazines showed a high thermal stability with T d20 of 350–465 °C and char yield of 67–78% at 500 °C.