Preparation and characterization of 3,3′,4,4′-benzophenone tetracarboxylic dianhydride-pyromellitic diahydride alternating polyimides

Four kinds of 3,3′,4,4′-benzophenone tetracarboxylic dianhydride (BTDA)-pyromelliitic dianhydride (PMDA) alternating polyimide (BTDA-PMDA API) were obtained by reacting 1 mol BTDA with 2 mol diamines to form BTDA chain-extended diamines (BTDA CED), followed by the addition of 1 mol PMDA to yield the BTDA-PMDA alternating polyamic acids (BTDA-PMDA APA), and finally by imidizing them thermally. BTDA CED were characterized by elemental analysis, infrared (IR), and ¹H-NMR spectroscopy. The structures of BTDA-PMDA APA and BTDA-PMDA API were investigated by IR and ¹H-NMR spectroscopy, and their thermal properties and interfacial tension were also studied. Furthermore, the characteristic properties of BTDA-PMDA API were compared with their corresponding homopolyimides from BTDA (BTDA HPI) and from PMDA (PMDA HPI). It was found that the alternating condensation polymerization is an effective method to modify polyimides interfacial tension with a small influence on the thermal stability. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 1585–1593, 1997     

Preparation of polyimides derived from biphenyltetracarboxylic dianhydrides and aromatic diamines bearing alkylene spacers

Four series of aromatic polyimides (PIs V–VIII) composed of biphenyltetracarboxylic dianhydrides (BPDAs) and aromatic diamines bearing alkylene spacers were prepared by two methods. Most polymers could be readily prepared in a one‐step method for the combination of a‐BPDA with α,ω‐bis(3‐aminophenoxy)alkanes, a‐BPDA with α,ω‐bis(4‐aminophenoxy)alkanes, and s‐BPDA with α,ω‐bis(3‐aminophenoxy)alkanes. However, the polymerization of s‐BPDA with α,ω‐bis(4‐aminophenoxy)alkanes gave powders. On the other hand, all four monomer combinations afforded the desired polyamic acid solution in a two‐step method. These polymer solutions could be cast into tough and flexible films, which were characterized by their inherent viscosity, differential scanning calorimetry, thermogravimetric analysis, and dynamic mechanical spectrometry measurements. The glass transition temperatures (T_gs) of the polymers were in the range of 110–240°C, but they were not clearly defined for PIs VIII and VI. The 5% weight loss temperatures were around 450°C for all prepared PIs. For PI VIII an “odd–even” behavior of the tensile properties of the films was detected, corresponding to the reported behavior of the melting temperatures. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 2404–2413, 1999     

Insensitive High Explosives II: 3,3′‐Diamino‐4,4′‐azoxyfurazan (DAAF)

This paper reviews the synthesis, properties, performance, and safety of the insensitive explosive 3,3′‐diamino‐4,4′‐azoxyfurazan (DAAF, C₄H₄N₈O₃), CAS‐No. [78644‐89‐0], and 18 formulations based on it. Though having a moderate crystal density only, DAAF offers high positive heat of formation and hence superior performance when compared with TATB. It is friction and impact insensitive but is more sensitive to shock than TATB and has an exceptionally small critical diameter and performs very well at low temperatures unlike other insensitive explosives. 39 references to the public domain are given. For Part I see Ref. [1].     

Preparation and properties of organo‐soluble polyimides based on 4,4′‐diamino‐3,3‐dimethyldiphenylmethane and conventional dianhydrides

4,4′‐Diamino‐3,3′‐dimethyldiphenylmethane was used to prepare polyimides in an attempt to achieve good organo‐solubility and light color. Polyimides based on this diamine and three conventional aromatic dianhydrides were prepared by solution polycondensation followed by chemical imidization. They possess good solubility in aprotonic polar organic solvents such as N‐methyl 2‐pyrrolidone, N,N‐dimethyl acetamide, and m‐cresol. Polyimide from 4,4′‐diamino‐3,3′‐dimethyldiphenylmethane and diphenylether‐3,3′,4,4′‐tetracarboxylic acid dianhydride is even soluble in common solvents such as tetrahydrofuran and chloroform. Polyimides exhibit high transmittance at wavelengths above 400 nm. The glass transition temperature of polyimide from 4,4′‐diamino‐3,3′‐dimethyldiphenylmethane and pyromellitic dianhydride is 370°C, while that from 4,4′‐diamino‐3,3′‐dimethyldiphenylmethane and diphenylether‐3,3′,4,4′‐tetracarboxylic acid dianhydride is about 260°C. The initial thermal decomposition temperatures of these polyimides are 520–540°C. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 1299–1304, 1999     

Reaction kinetics and thermal properties of epoxidised cresol novolac/4,4′‐diglycidyl (3,3′,5,5′‐tetramethylbiphenyl) epoxy resin composite cured with aromatic diamine

A series of novel composites based on different ratios of epoxidised cresol novolac (ECN) and 4,4′‐diglycidyl(3,3′,5,5′‐tetramethylbiphenyl) epoxy resin (TMBP) have been prepared with the curing agent 4,4′‐methylenediamine (DDM) and 4,4′‐diaminodiphenylsulfone (DDS), respectively. The investigation of cure kinetics was performed by differential scanning calorimetry using an isoconversional method. The high thermal stabilities of the cured samples were also studied by thermogravimetric analysis. In addition, no phase separation was observed for cured ECN/DDM and ECN/DDS blending with different amounts of TMBP by dynamic mechanical analysis and scanning electron microscopy. Moreover, the cured systems also exhibited excellent impact properties and low moisture absorption. All the results indicate that the ECN/TMBP/DDM and ECN/TMBP/DDS systems are promising materials in electronic packaging. Copyright © 2011 Society of Chemical Industry     

Synthesis and characterization of novel polyaspartimides derived from 2,2′‐dimethyl‐4,4′‐bis(4‐maleimidophenoxy)biphenyl and various diamines

A novel bismaleimide, 2,2′‐dimethyl‐4,4′‐bis(4‐maleimidophenoxy)biphenyl, containing noncoplanar 2,2′‐dimethylbiphenylene and flexible ether units in the polymer backbone was synthesized from 2,2′‐dimethyl‐4,4′‐bis(4‐aminophenoxy)biphenyl with maleic anhydride. The bismaleimide was reacted with 11 diamines using m‐cresol as a solvent and glacial acetic acid as a catalyst to produce novel polyaspartimides. Polymers were identified by elemental analysis and infrared spectroscopy, and characterized by solubility test, X‐ray diffraction, and thermal analysis (differential scanning calorimetry and thermogravimetric analysis). The inherent viscosities of the polymers varied from 0.22 to 0.48 dL g⁻¹ in concentration of 1.0 g dL⁻¹ of N,N‐dimethylformamide. All polymers are soluble in N‐methyl‐2‐pyrrolidone, N,N‐dimethylacetamide, N,N‐dimethylformamide, dimethylsulfoxide, pyridine, m‐cresol, and tetrahydrofuran. The polymers, except PASI‐4, had moderate glass transition temperature in the range of 188°–226°C and good thermo‐oxidative stability, losing 10% mass in the range of 375°–426°C in air and 357°–415°C in nitrogen. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 279–286, 1999     

Anionic block copolymerization of cyclotetrasiloxanes initiated by 4,4'‐bis(dimethyllithiioxylsilyl)diphenyl ether

The anionic copolymerization of cyclotetrasiloxanes initiated by 4,4′‐bis(dimethyllithiioxylsilyl)diphenyl ether (BDMOLiPE) was carried out for the preparation of poly(diphenyl‐dimethyl‐diphenyl)siloxane block copolymers (PMP). To reduce redistribution reaction, the lithium‐based dianionic initiator (BDMOLiPE) was first used for the copolymerization of the cyclotetrasiloxane monomers without solvent, with dimethyl formamide (DMF) as a promotor. The cyclotetrasiloxanes used involved octamethylcyclotetrasiloxane (D₄), octaphenylcyclotetrasiloxane (P₄), and tetramethyl‐tetravinylcyclotetrasiloxane (V₄). The copolymers obtained were characterized withproton nuclear magnetic resonance spectroscopy, infrared spectroscopy, intrinsic viscosity([η]) determination, transmission electron microscopy, and wide‐angle X‐ray diffraction analysis. The results illustrate that the products should belong to block copolymers but not be too perfect because the block copolymers were scrambled to a certain extent during the copolymerization process. However, we can approximately express them as PMP and PMVP, according to the different order of the feeding in raw materials. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1203–1210, 2001     

Investigation of the Solubility of 3,4‐Diaminofurazan (DAF) and 3,3′‐Diamino‐4,4′‐azoxyfurazan (DAAF) at Temperatures Between 293.15 K and 313.15 K

The solubilities of 3,4‐diaminofurazan (DAF) and 3,3′‐diamino‐4,4′‐azoxyfurazan (DAAF) were investigated in water, dichloromethane, acetonitrile, ethyl acetate, methanol, and acetone between 293.15 K and 313.15 K. The solubility was determined by high‐pressure liquid chromatography with ultraviolet detection. The solubilities of DAF and DAAF are increased with the increasing of temperature in all solvents studied. The enthalpy of solution in each solvent was calculated according to van't Hoff Equation.     

Synthesis and properties of poly(amide–imide)s based on N,N′‐bis(4‐carboxyphenyl)‐4,4′‐oxydiphthalimide,p‐aminobenzoic acid and various aromatic diamines

A new diimide–diacid monomer, N,N′‐bis(4‐carboxyphenyl)‐4,4′‐oxydiphthalimide (I), was prepared by azeotropic condensation of 4,4′‐oxydiphthalic anhydride (ODPA) and p‐aminobenzoic acid (p‐ABA) at a 1:2 molar ratio in a polar solvent mixed with toluene. A series of poly(amide–imide)s (PAI, III_a–m) was synthesized from the diimide–diacid I (or I′, diacid chloride of I) and various aromatic diamines by direct polycondensation (or low temperature polycondensation) using triphenyl phosphite and pyridine as condensing agents. It was found that only III_k–m having a meta‐structure at two terminals of the diamine could afford good quality, creasable films by solution‐casting; other PAIs III using diamine with para‐linkage at terminals were insoluble and crystalline; though III_g–i contained the soluble group of the diamine moieties, their solvent‐cast films were brittle. In order to improve their to solubility and film quality, copoly(amide–imide)s (Co‐PAIs) based on I and mixtures of p‐ABA and aromatic diamines were synthesized. When on equimolar of p‐ABA (m = 1) was mixed, most of Co‐PAIs IV had improved solubility and high inherent viscosities in the range 0.9–1.5 dl g^?1; however, their films were still brittle. With m = 3, series V was obtained, and all members exhibited high toughness. The solubility, film‐forming ability, crystallinity, and thermal properties of the resultant poly(amide–imide)s were investigated. © 2002 Society of Chemical Industry     

Crystallography and Structure–Property Relationships in 2,2′,2″,2′′′,4,4′,4″,4′′′,6,6′,6″,6′′′‐Dodecanitro‐1,1′ : 3′1″ : 3″,1′′′‐ Quaterphenyl (DODECA)

X‐ray crystallographic study of 2,2′,2″,2′′′,4,4′,4″,4′′′,6,6′,6″,6′′′‐dodecanitro‐1,1′ : 3′1″ : 3″,1′′′‐quaterphenyl (DODECA) has been carried out. Nonbonding interatomic distances of oxygen atoms inside of all the nitro groups are shorter than those corresponding to the intermolecular contact radii for oxygen. By means of the DFT B3LYP/6‐31(d, p) method a difference of 136 kJ mol⁻¹ between the X‐ray and DFT structures of DODECA was found. The bearer of the highest initiation reactivity in its molecule in solid phase should be the nitro group at 4′′′‐position, in contrast to those at 2′‐ or 2″‐positions in its isolated molecule. The most reactive nitro group in the DODECA molecule can be well specified by the relationship between net charges on nitro groups and charges on their nitrogen atoms, both of them for the X‐ray structure. The ¹⁵N chemical shift, corresponding to this nitro group for the initiation by impact and shock, correlates very well with these shifts of the reaction centers of the other six “genuine” polynitro arenes.     

Preparation of poly(amic acid) and polyimide derived from 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride with different diamines by microwave irradiation

Polycondensation‐type poly(amic acid) (PAA) was synthesized with 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride as a dianhydride monomer and 4,4′‐diaminodiphenylmethane and 4,4′‐oxydianiline as diamine monomers under microwave irradiation in dimethylformamide. Then, PAA was used to make polyimide (PI) by imidization at a low temperature. The structure and performance of the polymers were characterized with Fourier transform infrared (FTIR), proton nuclear magnetic resonance (¹H‐NMR), viscosity, X‐ray diffraction (XRD), and thermogravimetry (TG) curve analyses. The FTIR spectra of the polymers showed characteristic peaks of PI around 1779 and 1717 cm^?1. The ¹H‐NMR spectrum of PAA indicated a singlet at 6.55 ppm assigned to ? NHCO? and a singlet at 10.27 ppm assigned to carboxylic acid protons. The XRD spectrum demonstrated that the obtained PI had a low‐order aggregation structure with a d‐spacing of 0.5453 nm. The TG results revealed that the PI was thermally stable with 10% weight loss at 565°C in an N₂ atmosphere. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008     

Crystallography and Structure–Property Relationships of 2,2″,4,4′,4″,6,6′,6″‐Octanitro‐1,1′ : 3′,1″‐Terphenyl (ONT)

An X‐ray crystallographic study of 2,2″,4,4′,4″,6,6′,6″‐octanitro‐1,1′ : 3′,1″‐terphenyl (ONT) has been carried out. The dihedral angles between benzene rings vary from 84.9° to 89.4°. Nonbinding interatomic distances of oxygen atoms inside all the nitro groups are shorter than the intermolecular contact radii for oxygen. On the basis of the DFT B3LYP/6‐31(d, p) method it was found that the difference between the X‐ray structure in the solid phase and DFT result for the gas phase is 98 kJ mol⁻¹, and the bearer of the highest initiation reactivity of the ONT molecule in the solid phase should be the nitro group at 4″‐position, in contrast to those at 4′‐ or 6′‐position that play this role in the isolated molecule. It has been stated that the nitro groups at the reaction centers of the ONT molecule are relatively well specified by their ¹⁵N NMR chemical shifts.     

Effect of monomer composition on properties of copolyimides derived from 3,3′,4,4′‐biphenyltetracarboxylic dianhydride/4,4′‐oxydianiline/1,3‐bis (4‐aminophenoxy)benzene

A series of uncontrolled molecular weight homopolyimides and copolyimides based on 3,3′,4,4′‐biphenyltetracarboxylic dianhydride (s‐BPDA)/4,4′‐oxydianiline (4,4′‐ODA)/1,3‐bis(4‐aminophenoxy)benzene (TPER) were synthesized. All the polyimides displayed excellent thermal stability and mechanical properties, as evidenced by dynamic thermogravimetric analysis and tensile properties testing. A singular glass transition temperature (T_g) was found for each composite from either differential scanning calorimetry (DSC) or dynamic mechanical analysis (DMA), but the values determined from tan δ of DMA were much different from those determined from DSC and storage modulus (E′) of DMA. The Fox equation was used to estimate the random T_g values. Some composites exhibited re‐crystallization after quenching from the melt; upon heating, multi‐melting behavior was observed after isothermal crystallization at different temperatures. The equilibrium melting temperature was estimated using the Hoffman‐Weeks method. Additionally, DMA was conducted to obtain E′ and tan δ. Optical properties were strongly dependent on the monomer composition as evidenced by UV‐visible spectra. X‐ray diffraction was used to interpret the crystal structure. All the results indicated that composites with TPER composition ≥ 70% were dominated by the TPER/s‐BPDA polyimide phase, and ≤40% by the 4,4′‐ODA/s‐BPDA polyimide phase. When the ratio between the two diamines was close to 1:1, the properties of the copolyimides were very irregular, which means a complicated internal structure. Copyright © 2011 Society of Chemical Industry     

Synthesis and characterization of new cardo poly(ether imide)s derived from 9,9‐bis [4‐(4‐aminophenoxy)phenyl]xanthene

A series of new cardo poly(ether imide)s bearing flexible ether and bulky xanthene pendant groups was prepared from 9,9‐bis[4‐(4‐aminophenoxy)phenyl]xanthene with six commercially available aromatic tetracarboxylic dianhydrides in N,N‐dimethylacetamide (DMAc) via the poly(amic acid) precursors and subsequent thermal or chemical imidization. The intermediate poly(amic acid)s had inherent viscosities between 0.83 and 1.28 dL/g, could be cast from DMAc solutions and thermally converted into transparent, flexible, and tough poly(ether imide) films which were further characterized by X‐ray and mechanical analysis. All of the poly(ether imide)s were amorphous and their films exhibited tensile strengths of 89–108 MPa, elongations at break of 7–9%, and initial moduli of 2.12–2.65 GPa. Three poly(ether imide)s derived from 4,4′‐oxydiphthalic anhydride, 4,4′‐sulfonyldiphthalic anhydride, and 2,2‐bis(3,4‐dicarboxyphenyl))hexafluoropropane anhydride, respectively, exhibited excellent solubility in various solvents such as DMAc, N,N‐dimethylformamide, N‐methyl‐2‐pyrrolidinone, pyridine, and even in tetrahydrofuran at room temperature. The resulting poly(ether imide)s with glass transition temperatures between 286 and 335°C had initial decomposition temperatures above 500°C, 10% weight loss temperatures ranging from 551 to 575°C in nitrogen and 547 to 570°C in air, and char yields of 53–64% at 800°C in nitrogen. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Synthesis and properties of organosoluble poly(ether imide)s containing 4,4′(octahydro-4,7-methano-5H-inden-5-ylidene) cardo group

A series of organosoluble aromatic poly(ether imide)s (PEIs) VIIa-k were synthesized from 4,4′-[(octahydro-4,7-methano-5H-inden-5-ylidene)bis(1,4-phenylene)dioxy] diphthalic dianhydride (IV) and various aromatic diamines. PEIs synthesized through two-stage polymerization had inherent viscosities of 0.51–0.64 dL/g. This series of polymers could also be synthesized from IV and diamines in a small amount of refluxing m-cresol in a one-step process and had inherent viscosities of 0.65–0.87 dL/g. For the low melting point diamines (Vj and Vk), polymers could be obtained by bulk polymerization and had inherent viscosities of 0.36 and 0.41 dL/g. Polymers showed good organosolubility and could be cast into transparent, flexible, and tough polyimide films with good tensile properties. These PEIs had glass transition temperatures among 203–281°C. Thermogravimetric analyses established that these polymers were fairly stable up to 430°C, and the 10% weight loss temperatures were recorded in the range of 473–503°C in nitrogen and 481–512°C in air atmosphere. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 987–996, 1999     

The use of 3,3′,4′,5‐tetrachlorosalicylanilide as a chemical uncoupler to reduce activated sludge yield

To determine whether chemical additions can be used to reduce sludge production in biological wastewater treatment, 3,3′,4′,5‐tetrachlorosalicylanilide (TCS) was added to activated sludge cultures as a metabolic uncoupler. Batch tests confirmed that TCS is an effective chemical uncoupler in reducing the sludge yield at concentrations greater than 1.0 mg dm^?3; a TCS concentration of 1.0 mg dm^?3 reduced sludge yield by approximately 50%. Substrate removal capability and effluent nitrogen concentration were not affected adversely by the presence of TCS when dosed every other day in a range of 2.0–3.6 mg dm^?3 during the 40‐day operation of activated sludge batch cultures. Such sludge growth reduction was associated with the enhancement of microbial activities in terms of the specific oxygen uptake rate and dehydrogenase activity. Sludge settleability of the treated and control samples was qualitatively comparable and not significantly different. Filamentous bacteria continued to grow in sludge flocs only in the control reactor at the end of the 40‐day trial. These results suggest that TCS treatment of activated sludge systems may reduce excess sludge yield. Copyright © 2003 Society of Chemical Industry     

Gold(I)‐Catalyzed Cascade for Synthesis of Pyrrolo[1,2‐a:2′,1′‐c]‐/Pyrido[2,1‐c]pyrrolo[1,2‐a]quinoxalinones

An efficient and convenient method was developed for the one‐pot construction of the complex polycyclic heterocycles pyrrolo[1,2‐a:2′,1′‐c]‐/pyrido[2,1‐c]pyrrolo[1,2‐a]quinoxalinones from two simple starting materials via a gold(I)‐catalyzed domino reaction. This strategy presents an atom economical and environmentally friendly transformation, in which two new C N bonds and one new C C bond are formed in a one‐pot reaction process.     

Synthesis,Crystal Structure,and Thermal Behaviors of 3‐Nitro‐1,5‐bis(4,4′‐dimethylazide)‐1,2,3‐triazolyl‐3‐azapentane (NDTAP)

The energetic material, 3‐nitro‐1,5‐bis(4,4′‐dimethyl azide)‐1,2,3‐triazolyl‐3‐azapentane (NDTAP), was firstly synthesized by means of Click Chemistry using 1,5‐diazido‐3‐nitrazapentane as main material. The structure of NDTAP was confirmed by IR, ¹H NMR, and ¹³C NMR spectroscopy; mass spectrometry, and elemental analysis. The crystal structure of NDTAP was determined by X‐ray diffraction. It belongs to monoclinic system, space group C2/c with crystal parameters a=1.7285(8) nm, b=0.6061(3) nm, c=1.6712(8) nm, β=104.846(8)°, V=1.6924(13) nm³, Z=8, μ=0.109 mm⁻¹, F(000)=752, and D_c=1.422 g cm⁻³. The thermal behavior and non‐isothermal decomposition kinetics of NDTAP were studied with DSC and TG‐DTG methods. The self‐accelerating decomposition temperature and critical temperature of thermal explosion are 195.5 and 208.2 °C, respectively. NDTAP presents good thermal stability and is insensitive.     

Synthesis and properties of polyamides based on 5,5′‐bis[4‐(4‐aminophenoxy)phenyl]‐hexahydro‐4,7‐methanoindan

A new diamine 5,5′‐bis[4‐(4‐aminophenoxy)phenyl]‐hexahydro‐4,7‐methanoindan ( 3 ) was prepared through the nucleophilic displacement of 5,5′‐bis(4‐hydroxylphenyl)‐hexahydro‐4,7‐methanoindan ( 1 ) with p‐halonitrobenzene in the presence of K₂CO₃ in N,N‐dimethylformamide (DMF), followed by catalytic reduction with hydrazine and Pd/C in ethanol. A series of new polyamides were synthesized by the direct polycondensation of diamine 3 with various aromatic dicarboxylic acids. The polymers were obtained in quantitative yields with inherent viscosities of 0.76–1.02 dl g⁻¹. All the polymers were soluble in aprotic dipolar solvents such as N,N‐dimethylacetamide (DMAc) and N‐methyl‐2‐pyrrolidone (NMP), and could be solution cast into transparent, flexible and tough films. The glass transition temperatures of the polyamides were in the range 245–282 °C; their 10% weight loss temperatures were above 468 °C in nitrogen and above 465 °C in air. © 2000 Society of Chemical Industry     

Organosoluble and light‐colored fluorinated polyimides derived from 5,5′‐bis[4‐(4‐amino‐2‐trifluoromethylphenoxy) phenyl]‐4,7‐methanohexahydroindan

A novel bis(ether amine) monomer, 5,5′‐bis[4‐(4‐amino‐2‐trifluoromethylphenoxy)phenyl]‐4,7‐methanohexahydroindan ( 2 ), was synthesized through the nucleophilic aromatic substitution reaction of 5,5′‐bis‐(4‐hydroxyphenyl)‐4,7‐methanohexahydroindan with 2‐chloro‐5‐nitrobenzotrifluoride to yield the intermediate dinitro compound, followed by catalytic reduction with hydrazine and Pd/C. A series of polyimides were synthesized from 2 and various aromatic dianhydrides using a standard two‐stage process with chemical or thermal imidization of poly(amic acid). All of these polymer films were soluble in amide‐type solvents above 10% w/v, had tensile strengths of 97–117 MPa, and the 10% weight loss temperature was above 464 °C with their residues exceeding 46% at 800 °C in nitrogen. Compared with the non‐fluorinated polyimides, the fluorinated series were observed to have lower dielectric constants (2.92–3.28 at 1 MHz) and lower moisture absorptions (0.15–0.43 wt%) as well as lower color intensity and better solubility. Copyright © 2006 Society of Chemical Industry