Synthesis of multi‐block copolymer and its compatibilization to the blends of poly(ether ether ketone) with thermotropic liquid crystalline polymer

A multiblock copolymer (BCP) containing amorphous poly(aryl ether ketone) (PAEK) and thermotropic liquid crystalline polymer (TLCP) segments was synthesized. The chemical structure and properties of BCP were characterized by fourier‐transform infrared spectrometer (FTIR), differential scanning calorimeter (DSC), gel permeation chromatograms (GPC), thermogravimetry analysis, polar light microscope (PLM), and solubility test respectively. BCP can dissolve in chloroform because of soluble PAEK block bonded with TLCP block, which was insoluble. The peak of the original PAEK oligomer was no more present in the GPC traces of the block copolymer. These facts indicated that polymer synthesized should be copolymers of the two components rather than blends. A single T_g at 138.1°C and broad melting endotherm at 315.7°C can be observed. The liquid crystalline texture of BCP showed uniformity in the view after heat treated for 10 min above its T_m under PLM. Ternary blends of poly(ether ether ketone) (PEEK)/TLCP/BCP were prepared by extrusion and characterized by DSC. DSC results showed that the crystallization temperature of PEEK phase in the blends shifted higher with the addition of TLCP. Wide angle X‐ray diffraction investigations indicated that the crystalline structure of PEEK was not disturbed by blending or compatibilizing. Scanning electron microscope and mechanical tests confirmed the compatibilizing effect of BCP. Reduction in dispersed phase TLCP size was observed when 2 phr by weight of compatibilizer was added to the blend. Measurement of the tensile properties showed increased elongation as well as improved modulus and strength to some extent. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Isothermal crystallization behavior of nano-alumina particles-filled poly(ether ether ketone) composites

The isothermal crystallization behavior of nano-alumina particle-filled poly(ether ether ketone) (PEEK) composites has been investigated using differential scanning calorimeter. The results show that all the neat PEEK and nano-alumina-filled PEEK composites exhibit the double-melting behavior under isothermal crystallization. The peak crystallization times (τ_p) for all the neat PEEK and PEEK/aluminum oxide (Al₂O₃) composites increase with increasing crystallization temperature. Moreover, the crystallinity of the PEEK/Al₂O₃ composite with 7.5 wt % nano-filler content reached the maximum value of 44.8% at 290°C, higher than that of the neat PEEK polymer. From the lower value in τ_p and higher value in X_c for the PEEK/Al₂O₃ composites, the inclusion of the nano-alumina into the PEEK matrix favored the occurrence of heterogeneous nucleation. The Avrami exponents n of all the neat PEEK and PEEK/Al₂O₃ composites ranged from 2 to 3, and the n values for PEEK/Al₂O₃ composites were slightly higher than that of the neat PEEK polymer, indicating that the inclusion of the nano-filler made the crystallization mechanism more complex. However, the growth rate of crystallization was lowered as the nano- filler was introduced, and the decrease in growth rate reduced the grain size of the PEEK spherulites because of the lowering of molecule mobility during isothermal crystallization. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Phase and crystallization behavior of solution-blended poly(ether ether ketone) and poly(ether imide)

Results on solution-blended poly(ether ether ketone) (PEEK) and poly(ether imide) (PEI) blends are reported. Dichloroacetic acid was used as the cosolvent for blending. PEEK and PEI are confirmed to be miscible in the melt. The glass transition, T_g, behavior obeys the simple Fox equation or the Gordon-Taylor equation with the adjustable coefficient k = 0.86. This agrees with prior data on melt-blended PEEK/PEI blends. The T_g width of the amorphous PEEK/PEI blends was found to be broader than that of the pure components. The maximum broadening is about 10°C. The specific volume of the amorphous PEEK/PEI blends shows a slight negative deviation from linearity, indicating favorable interaction between PEEK and PEI. The spherulitic growth and resultant blend morphology at 270°C were studied by a cross-polarized optical microscope. The radial growth rate of PEEK spherulites formed from the miscible melt at 270°C decreases from 3.04 μm/min for PEEK/PEI 90/10 blend to 0.77 μm/min for PEEK/PEI 70/30 blend. The decrease in crystalization rate of PEEK from PEEK/PEI blends is attributable to the increase in blend T_g. A linear growth was observed for PEEK spherulites formed from miscible melt at 270°C in the early growth stage. The spherulitic growth deviated from linearity in the late stage of growth. PEEK spherulites formed from the miscible PEEK/PEI melt at 270°C are essentially volume-filling. The branches of the spherulites become more clear for PEEK spherulites formed from the blend than that formed from pure PEEK melt.     

Hybrid fiber fabric composites from poly ether ether ketone and glass fiber

Poly ether ether ketone (PEEK) polymer was extruded into filaments and cowoven into unidirectional hybrid fabric with glass as reinforcement fiber. The hybrid fabrics were then converted into laminates and their properties with special reference to crystallization behavior has been studied. The composite laminates have been evaluated for mechanical properties, such as tensile strength, interlaminar shear strength (ILSS), and flexural strength. The thermal behavior of the composite laminates were analyzed using differential scanning calorimeter, thermogravimetric analyzer, dynamic mechanical analyzer (DMA), and thermomechanical analyzer (TMA). The exposure of the fabricated composite laminates to high temperature (400 and 500°C) using radiant heat source resulted in an improvement in the crystallanity. The morphological behavior and PEEK resin distribution in the composite laminates were confirmed using scanning electron microscope (SEM) and nondestructive testing (NDT). Although DMA results showed a loss in modulus above glass transition temperature (T_g), a fair retention in properties was noticed up to 300°C. The ability of the composite laminates to undergo positive thermal expansion as confirmed through TMA suggests the potential application of glass–PEEK composites in aerospace sector. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci 117:1446–1459, 2010     

Synthesis and properties of novel copolymers of poly(ether ketone ether ketone ketone) and poly(ether ketone ketone ether ketone ketone) containing 1,4‐naphthylene moieties

A new monomer, 1,4‐bis(4‐phenoxybenzoyl)naphthalene (BPOBN), was conveniently synthesized via a simple synthetic procedure from readily available materials. A series of novel copolymers of poly(ether ketone ether ketone ketone) and poly(ether ketone ketone ether ketone ketone) containing 1,4‐naphthylene moieties were prepared by the Friedel‐Crafts acylation solution copolycondensation of terephthaloyl chloride (TPC) with a mixture of BPOBN and 4,4′‐diphenoxybenzophenone (DPOBPN), over a wide range of BPOBN/DPOBPN molar ratios, in the presence of anhydrous AlCl₃ and N‐methylpyrrolidone in 1,2‐dichloroethane. The copolymers with 10–40% BPOBN are semicrystalline and had remarkably increased T_gs over the conventional PEEK and PEKK due to the incorporation of 1,4‐naphthylene moieties in the main chains. The copolymers with 30–40 mol% BPOBN had not only high T_gs of 176–177°C, but also moderate T_ms of 332–338°C, which are suitable for the melt processing. These polymers had tensile strengths of 101.5–104.7 MPa, Young's moduli of 2.49–2.65 GPa, and elongations at break of 13.3–15.7% and exhibited high thermal stability and excellent resistance to organic solvents. POLYM. ENG. SCI., 56:566–572, 2016. © 2016 Society of Plastics Engineers     

Effective thermal conductivity and thermal properties of phthalonitrile‐terminated poly(arylene ether nitriles) composites with hybrid functionalized alumina

A polymer‐based thermal conductive composite has been developed. It is based on a dispersion of micro‐ and nanosized alumina (Al₂O₃) in the phthalonitrile‐terminated poly (arylene ether nitriles) (PEN‐t‐ph) via solution casting method. The Al₂O₃ with different particle sizes were functionalized with phthalocyanine (Pc) which was used as coupling agent to improve the compatibility of Al₂O₃ and PEN‐t‐ph matrix. The content of microsized functionalized Al₂O₃ (m‐f‐Al₂O₃) maintained at 30 wt % to form the main thermally conductive path in the composites, and the nanosized functionalized Al₂O₃ (n‐f‐Al₂O₃) act as connection role to provide additional channels for the heat flow. The thermal conductivity of the f‐Al₂O₃/PEN‐t‐ph composites were investigated as a function of n‐f‐Al₂O₃ loading. Also, a remarkable improvement of the thermal conductivity from 0.206 to 0.467 W/mK was achieved at 30 wt % n‐f‐Al₂O₃ loading, which is nearly 2.7‐fold higher than that of pure PEN‐t‐ph polymer. Furthermore, the mechanical testing reveals that the tensile strength increased from 99 MPa for pure PEN‐t‐ph to 105 MPa for composites with 30 wt % m‐f‐Al₂O₃ filler loading. In addition, the PEN‐t‐ph composites possess excellent thermal properties with glass transition temperature (T_g) above 184°C, and initial degradation temperature (T_id) over 490°C. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41595.     

Synthesis and properties of novel copolymers of poly(ether ketone diphenyl ketone ether ketone ketone) and poly(ether amide ether amide ether ketone ketone)

New monomers, 4,4′‐bis(4‐phenoxybenzoyl)diphenyl (BPOBDP) and N,N′‐bis(4‐phenoxybenzoyl)?4,4′‐diaminodiphenyl ether (BPBDAE), were conveniently synthesized via simple synthetic procedures from readily available materials. Novel copolymers of poly(ether ketone diphenyl ketone ether ketone ketone) (PEKDKEKK) and poly(ether amide ether amide ether ketone ketone) (PEAEAEKK) were synthesized by electrophilic Friedel‐Crafts solution copolycondensation of isophthaloyl chloride (IPC) with a mixture of BPOBDP and BPBDAE, over a wide range of BPOBDP/BPBDAE molar ratios, in the presence of anhydrous AlCl₃ and N‐methylpyrrolidone (NMP) in 1,2‐dichloroethane (DCE). The copolymers obtained were characterized by different physico‐chemical techniques. The copolymers with 10–40 mol% BPBDAE are semicrystalline and had remarkably increased T_gs over commercially available PEEK and PEKK due to the incorporation of amide and diphenyl linkages in the main chains. The copolymers IV and V with 30–40 mol% BPBDAE had not only high T_gs of 185–188°C, but also moderate T_ms of 326–330°C, having good potential for the melt processing. The copolymers IV and V had tensile strengths of 101.7–102.3 MPa, Young's moduli of 2.19–2.42 GPa, and elongations at break of 13.2–16.6% and exhibited high thermal stability and excellent resistance to organic solvents. POLYM. ENG. SCI., 54:1757–1764, 2014. © 2013 Society of Plastics Engineers     

High performance polymer composites on PEEK reinforced with aluminum oxide

A study on high performance poly(ether‐ether‐ketone) (PEEK) composites prepared by incorporating aluminum oxide (Al₂O₃), 0 to 50 wt % by hot compaction at 15 MPa and 350°C was described. Density, thermogravimetric analysis/differential scanning calorimetry, and scanning electron microscopy (SEM) were employed to evaluate their density, thermal stability, crystallinity, and morphology. Experimental density was found higher than theoretical density, which indicates that composite samples are sound. It was found that the addition of micron sized (< 15 μm) Al₂O₃ increased the peak crystallization temperature by 12°C when compared with neat PEEK with insignificant increase in melting temperature. Half‐time of crystallization is reduced from 2.05 min for the neat PEEK to 1.08 min for PEEK incorporated with 30 wt % Al₂O₃ because of the strong nucleation effect of Al₂O₃. The thermal stability of composites in air atmosphere was increased by 26°C. However, thermal stability in nitrogen atmosphere decreases at lower concentration of Al₂O₃ but increases above 20 wt % of Al₂O₃. Uniform dispersion of Al₂O₃ particles was observed in PEEK polymer matrix by SEM. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4623–4631, 2006     

Synthesis and characterization of poly(ether amide ether ketone)/poly(ether ketone ketone) copolymers

A new monomer, N,N′‐bis(4‐phenoxybenzoyl)‐m‐phenylenediamine (BPPD), was prepared by condensation of m‐phenylenediamine with 4‐phenoxybenzoyl chloride in N,N‐dimethylacetamide (DMAc). A series of novel poly(ether amide ether ketone) (PEAEK)/poly(ether ketone ketone) (PEKK) copolymers were synthesized by the electrophilic Friedel‐Crafts solution copolycondensation of terephthaloyl chloride (TPC) with a mixture of diphenyl ether (DPE) and BPPD, over a wide range of DPE/BPPD molar ratios, in the presence of anhydrous AlCl₃ and N‐methylpyrrolidone (NMP) in 1,2‐dichloroethane (DCE). The influence of reaction conditions on the preparation of copolymers was examined. The copolymers obtained were characterized by different physicochemical techniques. The copolymers with 10–25 mol % BPPD were semicrystalline and had remarkably increased T_gs over commercially available PEEK and PEKK due to the incorporation of amide linkages in the main chains. The copolymers III and IV with 20–25 mol % BPPD had not only high T_gs of 184–188°C, but also moderate T_ms of 323–344°C, having good potential for the melt processing. The copolymers III and IV had tensile strengths of 103.7–105.3 MPa, Young's moduli of 3.04–3.11 GPa, and elongations at break of 8–9% and exhibited outstanding thermal stability and good resistance to organic solvents. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis and properties of copolymers of poly(ether ether sulfone)/semiaromatic polyamides (PEES/PA)

Poly(ether ether sulfone) (PEES) containing semi‐aromatic polyamides with methylene units and ether linkage were synthesized through the copolymerization of m‐dihydroxybenzene, 4,4‐dichlorodiphenylsulfone (DCDPS) and 1,6‐N, N′‐bis(4‐fluorobenzamide) hexane (BFBH) by the method of nucleophilic polymerization. The inherent viscosities of the resultant different proportion of copolymers were in the range of 0.39–0.78 dL/g. These copolymers were found to have excellent thermal properties with glass transition temperatures (T_g) of 121–177°C, and initial degradation temperatures (T_d) of 417.5–432.5°C. These copolymers showed good mechanical properties with tensile strengths of 45–83 MPa, storage modulus of 1.8–2.6 GPa. The complex viscosities of pure Poly(ether ether sulfone) (PEES) was in the range of 176,000–309.8 Pas from 0.01 to 100 Hz, the complex viscosities of the copolymers decreased significantly with the increase of semi‐aromatic amide content, the copolymers of 20% decreased from 4371 to 142.4 Pas (from 0.01 to 100 Hz), and the copolymers of 70% dropped from 634.6 Pas to 55.97 Pas (from 0.01 Hz to 100 Hz). All copolymers exhibited non‐Newtonian and shear‐thinning behavior. These results suggested the resultant copolymers possess better melt flowability that is beneficial for the materials’ melt processing. POLYM. ENG. SCI., 56:44–50, 2016. © 2015 Society of Plastics Engineers     

Degradable epoxy resins based on bisphenol A diglycidyl ether and silyl ether amine curing agents

A series of silyl ether amine curing agents were synthesized by selective substitution reactions of chloroalkylsilanes or the transetherification of alkoxysilanes. Crosslinked networks were prepared by mixing a stoichiometric ratio of bisphenol A diglycidyl ether (D.E.R 331) with the amine curing agents. The networks were characterized by ATR‐FTIR spectroscopy, TGA, DSC, and DMA. The onset of thermal degradation, glass transition temperatures, and storage moduli for the networks were 350 °C, 70–108 °C, and 5–25 MPa, respectively. The degradation behavior of the cured samples was monitored for 30 days in PBS, NaOH 5% (w/v), and HCl 5% (v/v) solutions and the degradation products were characterized by spectroscopic methods. The thermal, mechanical, and degradation studies indicated that crosslink density, T_g, storage modulus, and the rate of degradation were affected by the functionality of the amine curing agents and the number of hydrolyzable silyl ether bonds present per mole of curing agent. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44620.     

Synthesis and properties of copolymers of poly(ether ketone ketone) and poly(ether amide ether amide ether ketone ketone)

Poly(aryl ether ketone)s (PAEKs) are a class of high‐performance engineering thermoplastics known for their excellent combination of chemical, physical and mechanical properties, and the synthesis of semicrystalline PAEKs with increased glass transition temperatures (T_g) is of much interest. In the work reported, a series of novel copolymers of poly(ether ketone ketone) (PEKK) and poly(ether amide ether amide ether ketone ketone) were synthesized by electrophilic solution polycondensation of terephthaloyl chloride with a mixture of diphenyl ether and N,N′‐bis(4‐phenoxybenzoyl)‐4,4′‐diaminodiphenyl ether (BPBDAE) under mild conditions. The copolymers obtained were characterized using various physicochemical techniques. The copolymers with 10–35 mol% BPBDAE are semicrystalline and have markedly increased T_g over commercially available poly(ether ether ketone) and PEKK due to the incorporation of amide linkages in the main chain. The copolymers with 30–35 mol% BPBDAE not only have high T_g of 178–186 °C, but also moderate melting temperatures of 335–339 °C, having good potential for melt processing. The copolymers with 30–35 mol% BPBDAE have tensile strengths of 102.4–103.8 MPa, Young's moduli of 2.33–2.45 GPa and elongations at break of 11.7–13.2%, and exhibit high thermal stability and good resistance to organic solvents. Copyright © 2010 Society of Chemical Industry     

Properties and crystallization kinetics of poly(ether ether ketone)‐co‐poly(ether ether ketone ketone) block copolymers

A series of block copolymers composed of poly(ether ether ketone) (PEEK) and poly(ether ether ketone ketone) (PEEKK) components were prepared from their corresponding oligomers via a nucleophlilic aromatic substitution reaction. Various properties of the copolymers were investigated with differential scanning calorimetry (DSC) and a tensile testing machine. The results show that the copolymers exhibited no phase separation and that the relationship between the glass‐transition temperature (T_g) and the compositions of the copolymers approximately followed the formula T_g = T_g1X₁ + T_g2X₂, where T_g1 and T_g2 are the glass‐transition‐temperature values of PEEK and PEEKK, respectively, and X₁ and X₂ are the corresponding molar fractions of the PEEK and PEEKK segments in the copolymers, respectively. These copolymers showed good tensile properties. The crystallization kinetics of the copolymers were studied. The Avrami equation was used to describe the isothermal crystallization process. The nonisothermal crystallization was described by modified Avrami analysis by Jeziorny and by a combination of the Avrami and Ozawa equations. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1652–1658, 2005     

Study on poly(ether ether ketone)/organically modified montmorillonite composites

Abstract

Novel poly(ether ether ketone) (PEEK)/organically modified montmorillonite (OMMT) composites containing 0–10 wt-% fractions of OMMT were prepared by melting blending method and the microstructure, thermal and mechanical properties were investigated using different characterisation techniques. X-ray diffraction and transmission electron microscopy showed that the OMMT was well dispersed with microscale in the PEEK matrix. Differential scanning calorimetry indicated that the glass transition temperature T _g and melt temperature T _m of PEEK/OMMT composites (POMCs) were hardly affected by the addition of OMMT, while the crystal temperature T _c decreased when the amount of OMMT excessed 1 wt-%. The data of thermogravimetric analysis exhibited that the thermal stability of POMCs in higher temperature region was better than that of pure PEEK. The results of mechanical properties test revealed that modulus and strength of POMCs increased with the content of OMMT, whereas the elongation at break and impact strength of POMCs decreased.     

Preparation and radiation shielding properties of Gd2O3/PEEK composites

Gd₂O₃/PEEK (poly ether ether ketone) composites were prepared on a twin‐screw extruder by the incorporation of Gd₂O₃ as a shield against X‐ray to PEEK matrix. The influence of Gd₂O₃ addition and surface treatment of the particles with sulfonated PEEK (SPEEK) on the morphology, thermal and mechanical properties of the composites was investigated by SEM, DSC, TGA and tensile tests respectively. DSC results showed that both the crystallization temperature (T_c) and melting temperature (T_m) of the composites decreased compared with pure PEEK at random filler content, which suggested that Gd₂O₃ hindered the process of PEEK nucleation. The tensile modulus of the composites increased with addition of Gd₂O₃ and the strain to break decreased. But the tensile modulus and strength of modified series were always higher than that of unmodified ones at the same filler content. The X‐ray shielding properties of composites apparently improved with the increment of the Gd₂O₃. The X‐ray transmittance (A) of 45% S₄GPEEK reduced greatly by about three to eight times compared with PEEKs in all energy range measured. POLYM. COMPOS., 36:651–659, 2015. © 2014 Society of Plastics Engineers     

Semi-aromatic copoly(ether ether amide): Synthesis and properties

A series of semi-aromatic copoly(ether ether amide)s (hydroquinone (HQ) (0%)-HQ (100%)) were synthesized by 1,1-bis(4-hydroxyphenyl)-1-phenylethane (BHPPE), 1,4-benzenediol (HQ) and 1,6-N,N′-bis(4-fuorobenzamide) hexane (BFBH) in this work. The inherent viscosities of copoly(ether ether amide)s were in the range of 0.487–0.769 dl g⁻¹. Following with increase of the content of HQ, the resultant polymers were converted from amorphous to crystalline. The copolymers were found to have high glass transition temperatures (T_g) of 141.4–155.6°C and weight-loss temperature (T_5%) of 423.3–434.3°C. They can be hot-pressed into films with tensile strength of 63.3–87.6 MPa, and storage modulus over 0.8 GPa at about 150°C, indicating good thermal and mechanical property of the obtained copolymers. The results of rheological property showed that the copolymers had good melt flowability and thermal stability. Additionally, the introduction of HQ improved the corrosion resistance of copolymers, the obtained polymers HQ (60%), HQ (80%) and HQ (100%) exhibited better corrosion resistance than that of HQ (0%). Especially, HQ (80%) and HQ (100%) were insoluble in organic polar solvents such as DMSO, DMF because of their crystalline nature, indicating that they had potential to be applied to the corrosion-resistant materials.     

Preparation,structures and properties of interpenetrating network structure-type Phosphate/PEEK composites with enhanced compressive strength and high temperature resistance

Phosphate/polyether ether ketone (PEEK) composites were successfully prepared by molding method and thermal treating at the temperature of 360 °C. The structures and compositions of phosphate/PEEK composites were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, differential scanning calorimetry and scanning electron microscopy. The mechanical properties thermal resistance and dielectric properties were strictly evaluated by the mechanical testing, thermogravimetric analysis and dielectric constant analysis. As the results, the interpenetrating network structure (IPNS) of Al₂O₃-phosphates was completely formed in PEEK matrix. And the phosphate/PEEK composite with 40% Al₂O₃-phosphate showed a 15.9% increasing for tensile strength and 74.5% increasing for compressive strength at room temperature. Besides, the phosphate/PEEK composite with 80 wt% Al₂O₃-phosphate dispalyed a dielectric constant of 4.0, a dielectric loss of 0.0601 and a Shore hardness of 91 HD. As the structural materials, these composites would exhibited the potential applications in aviation, aerospace and other fields.     

One‐pot synthesis of hyperbranched poly(aryl ether ketone)s for the modification of bismaleimide resins

Hyperbranched poly(aryl ether ketone)s with hydroxyl end groups (HBP‐OH) and high degree of branching value (83%) were synthesized via an A₂ + B₃ approach. The polymerization conditions (e.g., polymerization temperature and time, monomer concentration, stoichiometric ratio of functional groups) were explored to avoid the gelation. Allyl‐terminated hyperbranched PAEKs (HBP‐AL) with low molecular weight (M_n = 3.4 × 10³) and narrow polydispersity (PDI = 1.65) were obtained via the etherification of HBP‐OH and it has been used for the modification of bismaleimide (BMI) resins. The prepolymers showed good processibilities with a viscosity below 0.6 Pa s at 110°C, though the viscosities slightly increased as the increase of HBP‐AL contents. The cured BMI resins showed high glass transition temperatures (T_g > 320°C) and good thermal stabilities (T_d > 400°C, both in nitrogen and air). It is inspiring to note that the incorporation of HBP‐AL into BMI matrix results in a significant enhancement of toughness without any noticeable loss in modulus, processibility, and T_g. POLYM. ENG. SCI., 54:1675–1685, 2014. © 2013 Society of Plastics Engineers     

Copolymers of poly(arylene sulfide sulfone)/poly(ether sulfone): Synthesis,structure, and rheology properties

In order to overcome the poor flowability of poly(arylene sulfide sulfone) (PASS), we introduced ether bonds into the polymer main chain. A series poly(arylene ether sulfide sulfone) copolymers (PAESS) containing different proportion of ether bonds were synthesized with 4,4′‐dichlorodiphenyl sulfone (DCDPS), sodium sulfide (Na₂S·xH₂O), and 4,4′‐dihydroxydiphenyl ether (DHDPE). The copolymers were characterized by Fourier transform infrared (FTIR), ¹H‐nuclear magnetic resonance (NMR), differential scanning calorimetry, dynamic mechanical analysis (DMA), and rheometer. The results of FTIR and ¹H‐NMR indicate the copolymers are synthesized successfully. PAESS were found to have excellent thermal properties with glass transition temperature (T_g) of 175.7–219.1 °C and 5% weight lost temperature were all above 420 °C. The tensile and DMA test indicates that these resultant copolymers have good mechanical properties with tensile strength of 60 MPa and storage modulus of 1.5 GPa. From the results of rheology properties testing, we found that the melt stability and melt flowability of PASS were improved distinctly from 25,470 Pa s down to 355 Pa s with the incorporation of ether bonds. That will be quite beneficial to the processing of PASS, especially for the thermoforming of precision products. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46534.     

Synthesis and properties of organic soluble semicrystalline poly(aryl ether ketone)s copolymers containing phthalazinone moieties

A series of poly(aryl ether ketone)s (PAEK) copolymers containing phthalazinone moieties were synthesized by modest polycondensation reaction from 4‐(4‐hydroxyl‐phenyl)‐(2H)‐phthalazin‐1‐one (DHPZ), hydroquinone (HQ), and 1,4‐bis(4‐fluorobenzoyl)benzene (BFBB). The T_g values of these copolymers ranged from 168 to 235°C, and the crystalline melting temperatures varied from 285 to 352°C. By introducing phthalazinone moieties into the main chain, the solubility of these copolymers was improved in some common polar organic solvents, such as chloroform (CHCl₃), N‐methyl‐2‐pyrrolidinone (NMP), nitrobenzene (NB) and so on. The values of 5% weight loss temperatures were all higher than 510°C in nitrogen. The crystal structures of these copolymers were determined by wide‐angle X‐ray diffraction (WAXD), which revealed that they were semicrystalline in nature, and the crystal structure of these copolymers was orthorhombic, equal to poly(ether ether ketone ketone)s. As phthalazinone content in the backbone varied from 0 to 40 mol % (mole percent), the cell parameters of these copolymers including the a, b, and c axes lengths ranged from 7.76 to 7.99 Å, 6.00 to 6.14 Å, and 10.10 to 10.19 Å, respectively. The degree of crystallinity (via differential scanning calorimetry) decreased from 37.70% to 16.14% simultaneously. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1744–1753, 2007