New organosoluble poly(arylene ether nitrile) copolymers based on 9,9-bis(3,5-dimethyl-4-hydroxyphenyl)xanthene

High Performance Polymers

et al. 2018

Poly(arylene ether nitrile) (PEN) copolymers (HQ/RS-PEN) containing different proportions of hydroquinone (HQ-PEN) block and resorcinol (RS-PEN) block were synthesized, and their crystalline, mechanical, and dielectric properties were investigated. Three HQ/RS-PEN copolymers with 10%, 20%, and 30% of RS-PEN blocks were prepared via condensation polymerization of HQ and RS with 2,6-dichlorobenzonitrile. The PEN copolymers were characterized and confirmed by Fourier transform infrared spectroscopy, intrinsic viscosity, and thermal analyses. With the addition of RS-PEN block, the flexibility of PEN copolymers was increased. In addition, even though the high loading content of RS-PEN block was incorporated, the PEN copolymers still exhibited relatively high dielectric constant, whereas the dielectric loss decreased. Furthermore, to investigate the effect of treatment time and temperature on the physical properties of crystalline PEN copolymers, HQ/RS-PEN20 was isothermally treated at different temperatures (280°C, 300°C, 310°C, 320°C, and 330°C) for a constant time and at a constant time for different hours (1, 2, 3, 4, and 5 h). After the optimization of the crystallization of HQ/RS-PEN polymer, excellent mechanical and dielectric properties of copolymers were obtained. The results showed that when isothermally treated at 320°C for 2 h, the HQ/RS-PEN20 showed optimal properties of tensile strength of 117.6 MPa and dielectric constant of 4.07 at 1 kHz.

Section: Methodsmentioning

confidence: 99%

Mechanical and dielectric properties of crystalline poly(arylene ether nitrile) copolymers

High Performance Polymers

et al. 2018

“…The decreasing steric congestion contributed by HHPZ between macromolecular chains produced more free volume for solvent molecules to diffuse into, eventually resulting in improvement of solubility compared with other PEN materials. 10,13,14 Increasing solubility of PPEN-PN was beneficial for preparing fiber-reinforced laminates.…”

Section: Processability Of the Resinsmentioning

confidence: 99%

“…Researchers have demonstrated that poor solubility of PEN-PN could be overcome by introduction of twisted non-coplanar structure 4-(4-hydroxyphenyl)(2 H)-2,3-phthalazin-1-one (HHPZ) without sacrificing thermal and mechanical properties ( Figure 2). [7][8][9][10][11][12][13][14][15][16][17][18] Furthermore, it was found that blending high-performance oligomer with low-melt viscosity monomers had significant advantages of reducing processing viscosity for the resins. Therefore, preparation of mixed phthalonitrile resins could also be strategic for solving the processing problems.…”

Section: Introductionmentioning

confidence: 99%

Novel phthalonitrile-based composites with excellent processing, thermal, and mechanical properties

High Performance Polymers

Zong

et al. 2017

Phthalonitrile resins exhibit excellent thermostability and mechanical strength after curing. However, poor processability made them difficult to fabricate fiber-reinforced composites with desirable integrated performance. In this article, a novel mixed phthalonitrile resin was developed to be used as the matrix for glass fiber–reinforced laminates. Poly (aryl ether nitrile phthalazinone) oligomer end-capped by phthalonitrile units (PPEN-PN) was firstly designed and blended with bisphenol-based phthalonitrile monomers (BP-PN) (Figure 1), which were obtained according to the literature procedure. A novel mixed curing agent (zinc chloride and 4,4-diamine-diphenylsulfone) was also exploited to accelerate curing rate of the resins. Solubility tests, differential scanning calorimetry and rheological studies revealed that the mixed resins exhibited good processability with low processing viscosity. Thermal gravimetric analysis indicated that the cured resins were stable below 530 to approximately 570 °C in nitrogen atmosphere after low-cost curing procedure. In air, char yields of the resins were between 30 to approximately 40% when heated to 800 °C. The laminates reinforced by E-glass fiber cloth possessed a bending strength of 668 MPa with interlaminar shear strength of 84.6 MPa at room temperature. 50% of the strength and modulus was maintained when heated to 400 °C. Consequently, this type of laminates may be potential candidates for aerospace applications.

“…Such materials have been widely used in the aerospace, communications, electronics, and other industries . Among these materials, poly(arylene ether nitrile) (PEN), as a typical representative, has attracted considerable attention in recent decades …”

Section: Introductionmentioning

confidence: 99%

Crystallinity of poly(arylene ether nitrile) copolymers containing hydroquinone and bisphenol A segments

Tong

J of Applied Polymer Sci

et al. 2018

The hydroquinone (HQ) and bisphenol A (BPA) type poly(arylene ether nitrile) (PEN) (HQ/BPA-PEN) were synthesized through nucleophilic aromatic substitution polymerization from HQ, BPA, and 2,6-dichlorobenzonitrile (DCBN). The prepared copolymers were characterized by intrinsic viscosity, Fourier transform infrared (FTIR), and dynamic rheological analysis. The properties of resultant copolymers were studied by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and mechanical testing. The results showed that the PEN copolymers exhibited crystallization performance with excellent thermal and mechanical properties. HQ/BPA-PEN10 was made into films by solution-casting process and then were treated at different temperatures (200, 260, 280, 300, 310, and 320 8C) for different times (1, 2, 3, 4, and 5 h) to investigate the crystallinity. Results showed that when isothermal treatment temperature is 310 8C and isothermal treating time is 4 h, HQ/BPA-PEN10 showed best properties. At this condition, the melting enthalpy, crystallinity, tensile strength, and elongation at break of the sample is 17.7 J/g, 14.11%, 132.9 MPa, and 6.1%, respectively.