Ruei-Shin Chen

Synthesis and properties of new organo‐soluble and strictly alternating aromatic poly(ester‐imide)s from 3,3‐bis[4‐(trimellitimidophenoxy)phenyl]phthalide and bisphenols

A series of new strictly alternating aromatic poly(ester-imide)s having inherent viscosities of 0.20 - 0.98 dL/g was synthesized by the diphenylchlorophosphate (DPCP) activated direct polycondensation of the preformed imide ring-containing di- acid, 3,3-bis(4-(trimellitimidophenoxy)phenyl)phthalide (I), with various bisphenols in a medium consisting of pyridine and lithium chloride. The diimide- diacid I was prepared from the condensation of 3,3-bis(4-(4-aminophenoxy)phenyl)phthalide and trimellitic anhydride. Most of the resulting polymers showed an amorphous nature and were readily soluble in a variety of organic solvents such as N-methyl-2-pyrrolidone (NMP) and N,N-dimethylacetamide (DMAc). Transparent and flexible films of these polymers could be cast from their DMAc solutions. The cast films had tensile strengths ranging 66 -105 MPa, elongations at break from 7-10%, and initial moduli from 1.9 -2.4 GPa. The glass-transition temperatures of these polymers were recorded between 208 -275 °C. All polymers showed no significant weight loss below 400 °C in the air or in nitrogen, and the decomposition temperatures at 10% weight loss all occurred above 460 °C.

Synthesis and properties of soluble colorless poly(amide-imide)s based on N,N'-bis(3-carboxyphenyl)-4,4'-oxydiphthalimide and various aromatic diamines

Abstract The diimide–diacid monomer, N,N ′-bis(3-carboxyphenyl)-4,4′-oxydiphthalimide ( I ), was prepared by azeotropic condensation of 4,4′-oxydiphthalic anhydride and m -aminobenzoic acid at a 1:2 molar ratio in polar solvent and toluene. A series of organosoluble and colorless poly(amide–imide)s with inherent viscosities ranging from 0.95 to 1.70xa0dl/g were synthesized from diimide–diacid I and various aromatic diamines by the direct polycondensation using triphenyl phosphite and pyridine as condensing agents. From UV–visible spectrum and resulting parameters of Macbeth Color-eye colorimeter, these polymers were much lighter in color than other analogous polymers. All the poly(amide–imide)s were readily soluble in a variety of organic solvents such as NMP, DMAc, DMF, and DMSO, and some even could be dissolved in less polar solvents such as m -cresol and pyridine. The cast films exhibited tensile strengths ranging from 82 to 106xa0MPa, elongations to break from 10 to 15%, and initial moduli from 1.9 to 2.3xa0GPa. Poly(amide–imide)s had glass transition temperatures of 221–276°C and 10% weight loss temperatures of 551–570°C in nitrogen and 548–578°C in air indicating excellent thermal stability.

Synthesis and properties of organosoluble poly(amide-imide)s with propeller-shaped 1,1,1-triphenylethane units in the main chain

A dicarboxylic acid {1,1-bis[4-(4-trimellitimidophenoxy)phenyl]-1-phenylethane (II)} bearing two performed imide rings was prepared from the condensation of 1,1-bis[4-(4-aminophenoxy)phenyl]-1-phenylethane and trimellitic anhydride in a 1/2 molar ratio. A novel family of poly(amide-imide)s with inherent viscosities of 0.83–1.51 dL/g was prepared by triphenyl phosphite-activated polycondensation from the diimide-diacid II with various aromatic diamines in a medium consisting of N-methyl-2-pyrrolidinone (NMP), pyridine, and calcium chloride. Because the 1,1,1-triphenylethane group of II was unsymmetrical, most of the resulting polymers showed an amorphous nature and were readily soluble in polar solvents such as NMP and N,N-dimethylacetamide. All the soluble poly(amide-imide)s afforded tough, transparent, and flexible films, which had tensile strengths ranging from 88 to 102 MPa, elongations at break from 6 to 11%, and initial moduli from 2.23 to 2.71 GPa. The synthesized poly(amide-imide)s possessed glass-transition temperatures from 250 to 287 °C. The poly(amide-imide)s exhibited excellent thermal stabilities and had 10% weight losses from 501 to 534 °C under a nitrogen atmosphere. A comparative study of some corresponding poly(amide-imide)s is also presented.

Preparation and properties of new poly(amide-imide)s based on 1,4-bis(4-trimellitimidophenoxy)naphthalene and aromatic diamines

A diimide dicarboxylic acid, 1,4-bis(4-trimellitimidophenoxy)naphthalene (1,4-BTMPN), was prepared by condensation of 1,4-bis(4-aminophenoxy)naphthalene and trimellitic anhydride at a 1 : 2 molar ratio. A series of novel poly(amide-imide)s (IIa–k) with inherent viscosities of 0.72 to 1.59 dL/g were prepared by triphenyl phosphite-activated polycondensation from the diimide-diacid 1,4-BTMPN with various aromatic diamines (Ia–k) in a medium consisting of N-methyl-2-pyrrolidinone (NMP), pyridine, and calcium chloride. The poly(amide-imide)s showed good solubility in NMP, N,N-dimethylacetamide, and N,N-dimethylformamide. The thermal properties of the obtained poly(amide-imide)s were examined with differential scanning calorimetry and thermogravimetry analysis. The synthesized poly(amide-imide)s possessed glass-transition temperatures in the range of 215 to 263°C. The poly(amide-imide)s exhibited excellent thermal stabilities and had 10% weight losses at temperatures in the range of 538 to 569°C under a nitrogen atmosphere. A comparative study of some corresponding poly(amide-imide)s also is presented.

Organosoluble polyimides and copolyimides based on 1,1‐bis[4‐(4‐aminophenoxy)phenyl]‐1‐phenylethane and aromatic dianhydrides

1,1-Bis[4-(4-aminophenoxy)phenyl]-1-phenylethane (BAPPE) was prepared through nucleophilic substitution reaction of 1,1-bis(4-hydroxyphenyl)-1-phenylethane and p-chloronitrobenzene in the presence of K 2 CO 3 in N,N-dimethylformamide, followed by catalytic reduction with hydrazine and Pd/C. Novel organosoluble polyimides and copolyimides were synthesized from BAPPE and six kinds of commercial dianhydrides, including pyromellitic dianhydride (PMDA, I a ), 3,3,4,4-benzophenonetetracarboxylic dianhydride (BTDA, I b ), 3,3,4,4- biphenyltetracarboxylic dianhydride (BPDA, I c ), 4,4-oxydiphthalic anhydride (ODPA, I d ), 3,3,4,4-diphenylsulfonetetracarboxylic dianhydride (DSDA, I e ) and 4,4-hexafluoroisopropylidenediphthalic anhydride (6FDA, If). Differing with the conventional polyimide process by thermal cyclodehydration of poly(amic acid), when polyimides were prepared by chemical cyclodehydration with N-methyl-2-pyrrolidone as used solvent, resulted polymers showed good solubility. Additional, I a,b were mixed respectively with the rest of dianhydrides (I c-f ) and BAPPE at certain molar ratios to prepare copolyimides with arbitrary solubilities. These polyimides and copolyimides were characterized by good mechanical properties together with good thermal stability.

Preparation and characterization of colorless alternate poly(amide-imide)s based on trimellitic anhydride and 2,2-bis[4-(3-aminophenoxy)phenyl]sulfone

Alternate poly(amide-imide) [P(A-alt-I)] was synthesized from two aromatic diamines and trimellitic anhydride (TMA). When the diamine was 2,2-bis[4-(3-aminophenoxy)phenyl]sulfone (BAPS), the resulted P(A-alt-I) was found to be of light color. Specifically, when BAPS was located between two amide groups in the P(A-alt-I) chain, the P(A-alt-I) was almost colorless. A series of P(A-alt-I)s (Series III) containing BAPS was synthesized through direct polycondensation of an aromatic dicarboxylic acid prepared from various aromatic diamines and TMA, as well as BAPS. Polymers of Series III were much lighter in color than those of the isomeric series (BAPS was located between two imide group). The series of P(A-alt-I)s III had inherent viscosities ranging 0.69–1.35 dL/g and good solubility in various solvents. The tensile strengths, elongations to break, and initial moduli of the films were 72–107 MPa, 7–12% and 1.93–2.39 GPa, respectively, and most of the films had no yielding. Polymers of Series III had glass transition temperatures 210–272°C and 10% weight loss temperatures in nitrogen 518–545°C, indicating excellent thermal stability.

Synthesis and characterization of organosoluble copolyimides based on 2,2-bis[4-(4-aminophenoxy) phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane and a pair of commercial aromatic dianhydrides

Organosoluble homopolyimides (PIs) and copolyimides (CoPIs) were synthesized from 2,2-bis[4-(4-aminophenoxy)phenyl]propane (BAPP) or 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane (6FBAPP) and six kinds of commercial aromatic dianhydrides (PMDA, IIa ; BTDA, IIb ; BPDA, IIc ; ODPA, IId ; DSDA, IIe ; 6FDA, IIf ). Although BAPP and IId∼f could prepare three kinds of soluble PIs (III-Ad∼f ), likewise 6FBAPP and IIc∼f could prepare four PIs (III-Bc∼f ), the insoluble PIs were synthesized from these two diamines and other dianhydrides. However, soluble CoPIs could be prepared by alternative copolycondensation from a pair of dianhydrides of soluble PIs and insoluble PIs in certain molar ratios (m1/m2). The ratios of m1/m2 of BAPP/PMDA series CoPIs (IVm1(d–f)/m2a ) ranged from 3–5, but ratios of 6FBAPP/PMDA series CoPIs (Vm1(c∼f)/m2a ) decreased to 2–3. The m1/m2 of the BAPP/BTDA and 6FBAPP/BTDA series CoPIs were 2, while the BAPP/BPDA series were between 1–2. Composition, solubility, tensile properties and thermal properties of these CoPIs synthesized via a two-stage thermal cyclodehydration were determined and were compared with their corresponding PIs.

Synthesis and properties of new soluble poly(amide–imide–imide)s based on tetraimide-dicarboxylic acid condensed from ODPA, BAPP and p-ABA, and various aromatic diamines

Abstract A new-type of tetraimide-dicarboxylic acid ( I ) was synthesized starting from ring-opening addition of p -aminobenzoic acid ( p -ABA), 4,4′-oxydiphthalic anhydride (ODPA) and 2,2-bis[4-(4-aminophenoxy)phenyl]propane (BAPP) at a 2:2:1 molar ratio in N -methyl-2-pyrrolidone (NMP), followed by cyclodehydration to the diacid I . A series of poly(amide–imide–imide)s ( III a–i ) with inherent viscosities of 0.82–1.20xa0dlxa0g −1 was prepared by triphenyl phosphite-activated polycondensation from the tetraimide-diacid ( I ) with various aromatic diamines ( II a–i ) in a medium consisting of NMP, pyridine, and calcium chloride. Most of the polymers were readily soluble in a variety of organic solvents such as NMP, N , N -dimethyl acetamide (DMAc), dimethyl sulfoxide (DMSO), and even in less polar m -cresol. In comparison with corresponding poly(amide–imide)s ( IV a–i ), the solubilities of poly(amide–imide–imide)s ( III a–i ) were largely improved. Most of the polymers ( III ) afforded tough, transparent, and flexible films, which had tensile strengths ranging from 96 to 107xa0MPa, elongations at break from 9 to 16%, and initial moduli from 2.0 to 2.3xa0GPa. The glass transition temperatures of polymers recorded at 257–278xa0°C. They had 10% weight loss temperature above 540xa0°C and left more than 46% residue even at 800xa0°C in nitrogen.

Synthesis and characterization of new type soluble poly(amide–imide)s based on 6FDA imide modified polyterephthalamides

A series of new poly(amide–imide)s (PAIs, series III) with good processability and characteristics was synthesized by utilizing organosoluble polyimide (PI, 6FDA–PI series) to improve poor-solubility polyamide (PA, PTPA series), which used terephthalic acid (TPA) as a monomer. The III series PAIs were synthesized starting from the 2 : 1 molar ratio of aromatic diamines (I) and 6FDA to prepare imide ring-preformed diamines (II) and then reacted with equimolar amount of TPA by direct polycondensation. Furthermore, by adjustment of the stoichiometry of the I, II, and TPA monomers, PAIs IV having various components were prepared. Most of the resulting PAIs having inherent viscosities between 0.70 and 1.74 dL/g were obtained in quantitative yields, and they were readily soluble in polar solvents such as N,N-dimethylacetamide, N-methyl-2-pyrrolidone, dimethylformamide, and dimethyl sulfoxide. All of the soluble PAIs afforded transparent, flexible, and tough films. The glass-transition temperatures of PAIs III were in the range of 236–256 °C, and the 10% weight loss temperatures were recorded at 522–553 °C in nitrogen. The char yields of the III series polymers in nitrogen atmosphere were all higher than 56% even at 800 °C.

Syntheses of regular copolyamides using triphenyl phosphite and pyridine

In this article, a method of preparing of regular copolyamide (co-PA) in a reactor using triphenyl phosphite/pyridine as the activating agent was investigated. In two-step reactions of copolymers prepared from two kinds of dicarboxylic acids and one kind of diamine, oligomer PAs containing amine end groups were first synthesized; then, the second dicarboxylic acid was added to the same reactor to polymerize high molecular weight and regular co-PAs. However, when oligomers having carboxylic acid end groups were first prepared and another kind of diamine was added, the degree of polymerization was low. The reason proposed was that if the oligomer has an amine end group, it would coexist with the activating agent without deactivating; if the end group was the carboxylic acid end group, deactivation would occur.