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Abstract. Phthalonitrile and benzoxazine have been considered as high-performance materials in the field of heterocyclic chemistry. The polymerization of phthalonitrile and benzoxazine accelerated by active phenolic hydroxyl has attracted wide interests. In this work, self-promoted polymerization behavior and processability of phthalonitrile containing benzoxazine (BA-ph) with bisphenol-A (BPA) were investigated. Results revealed that BA-ph/BPA exhibited representative doublestage curing behaviors corresponding to the ring-opening polymerization of benzoxazine rings and ring-formation polymerization of nitrile groups. Compared with that of BA-ph, processability of BA-ph/BPA was improved and could be tuned by varying BPA contents, processing temperature and time. Then BA-ph/BPA/glass fiber (GF) composite laminates were prepared. In comparison with that of BA-ph/GF laminates (542 MPa and 25.8 GPa), the flexural strength and modulus were up to 789 MPa and 23.6 GPa, respectively. Moreover, double T g s were observed at temperature around 200~300°C and 300~380°C, indicating microphase separation during the polymerization of oxazine rings and nitrile groups, confirmed by the scanning electron microscopic (SEM) images. Thermal stabilities demonstrated that all BA-ph/BPA/GF composites exhibited high T 10% up to 510°C. The systematic study of BA-ph/BPA system could enrich our knowledge on phthalonitrile-based resins in industrial applications, especially in the areas which require excellent mechanical properties and high temperature resistance.

An easy and efficient approach by using carboxyl functionalized CNTs (CNT-COOH) as nano reinforcement was reported to develop advanced thermosetting composite laminates. Benzoxazine containing cyano groups (BA-ph) grafted with CNTs (CNT-g-BA-ph), obtained from the in situ reaction of BA-ph and CNT-COOH, was used as polymer matrix and processed into glass fiber (GF)-reinforced laminates through hot-pressed technology. FTIR study confirmed that CNT-COOH was bonded to BA-ph matrices. The flexural strength and modulus increased from 450 MPa and 26.4 GPa in BA-ph laminate to 650 MPa and 28.4 GPa in CNT-g-BA-ph/GF composite, leading to 44 and 7.5% increase, respectively. The SEM image observation indicated that the CNT-COOH was distributed homogeneously in the matrix, and thus significantly eliminated the resin-rich regions and free volumes. Besides, the obtained composite laminates showed excellent thermal and thermal-oxidative stabilities with the onset degradation temperature up to 624 C in N 2 and 522 C in air. This study demonstrated that CNT-COOH grafted on thermosetting matrices through in situ reaction can lead to obvious mechanical and thermal increments, which provided a new and effective way to design and improve the properties of composite laminates.

Background To compare the results between type I tympanoplasty performed with transcanal endoscopic ear surgery (TEES) and microscopic ear surgery (MES) for treatment of chronic otitis media in a homogenous group of patients. Methods A retrospective study was performed in our department between January 2011 and January 2016 to review primary type I tympanoplasty cases with a subtotal perforation, an intact ossicular chain, a dry ear for at least 1 month, normal middle ear mucosa, and a follow-up period of at least 6 months post surgery. The adoption of TEES or MES was divided temporally (before and since 2013). TEES was undertaken in 224 patients (224 ears) and MES in 121 patients (121 ears). Results The successful graft take rate was 94.64% (212/224) in the TEES group and 90.91% (110/121) in the MES group (P = 0.239). The improvements in the air conduction levels between the 2 groups were not statistically different at 1, 3, or 6 (> 6) months (P > 0.05) after surgery. The improvements in the air–bone gaps were not significantly different between the 2 groups (P > 0.05). The average hearing gains in the TEES group 6 (and > 6) months post surgery were 11.85 ± 5.47 dB, which was better than 10.48 ± 5.18 dB in the MES group (P = 0.031). The use of medical resources was lower in the TEES group than in the MES group regarding the average operating time (49.22 ± 8.24 min vs 81.22 ± 14.73 min, respectively; P < 0.0001). Patients receiving MES had a significant higher incidence of the wound problems (ear pain, numbness around the ears, and wet ear; P < 0.05). Conclusion TEES for type I tympanoplasty seems to achieve a shorter operative time and ideal tympanic membrane healing rate and hearing results in patients with chronic otitis media.

Dicarboxylic acid-containing 1,3-benzoxazine was synthesized and chemically bonded on iron carbonyl particles using a post-coating method. Novel organic-inorganic hybrid magnetic composites were prepared via the interfacial reaction between magnetic phthalonitrile prepolymers and the benzoxazine functional coatings that chemically modified the iron carbonyl particles. The results showed that, compared with pure iron carbonyl particles, the modified particles could cure the phthalonitrile prepolymers efficiently and improve the interfacial compatibility of the functional composites. The magnetic composites with chemically modified particles exhibited stronger magnetism in comparison to composites containing bare particles: the saturation magnetization of the magnetic composites with equal concentration (5 wt%) of Fe(CO) 5 increased from 41.12 to 48.82 emu g −1 . Also, the magnetic composites obtained demonstrated excellent thermal stability up to 500 • C.