Syntheses and Properties of Different Degree of Branching Polyamides Derived from an ABB′ Type Monomer, 4-(2,4-Diaminophenoxy) Benzoic Acid

Abstract

ABSTRACT:Hyperbranched polyamides with different degree of branchings (DBs) were prepared by different polycondensation conditions from an ABB 0 type monomer, 4-(2,4-diaminophenoxy)benzoic acid. Polyamide (PA1) with multi-amino groups prepared in the presence of (2,3-dihydro-2-thioxo-3-benzoxazolyl) phosphonic acid diphenyl ester (DBOP) and triethylamine as condensing agents at room temperature had lower DB of 0.1. Polyamide (PA2) with multi-amino groups prepared in the presence of triphenylphosphite and pyridine as condensing agent at 100 C had higher DB of 0.2. The free amino groups of both polyamides were modified by acetyl chloride, benzoyl chloride and phthalic anhydride, respectively, to give corresponding modified polyamides. The solubility and thermal properties were not influenced by the different DBs but were influenced by the end groups. Strong films were prepared from polyamides with lower DBs and polyamides with amino groups. [DOI 10.1295 Hyperbranched polymers have been attracting considerable attention due to their unique characteristics: branched structure, which results in low viscosity and high solubility, and their large number of end groups, which can be modified for many applications.1,2 However, most of hyperbranched polymers derived from AB 2 monomers do not afford strong films due to lack of chain entanglements, which is a necessity for the mechanical properties of engineering plastics. We have previously reported a new method for increasing chain entanglement by preparing low degree of branching hyperbranched polymers from an ABB 0 type monomer. 3On the other hand, Frey has pointed out that DB statically approached 0.5 in case of the polymerization of AB 2 monomers. 4 Most of the hyperbranched polymers reported in the literature have actually DBs close to 0.5. There have been several attempts to increase DBs: (1) polymerization of dendrons having prefabricated dendritic units; 5 (2) polymerization of AB x monomers in the presence of core molecules (Bf); 6,7 (3) enhancement of the reactivity of linear units formed during the polymerization. [8][9][10] Thompson et al. also prepared a series of hyperbranched poly(ether imide)s with different degrees of branching by changing the polymerization time from 2.5 to 20 min. 11 The changes in DB are a result of molecular rearrangements occurring via a transetherification mechanism.Generally speaking, because reaction rate constants dependent on temperature and activation energy, for an ABB 0 monomer, the relative reactivity of the B and B 0 functional group may change as changing reaction conditions (temperature or condensing agent). That is, it is possible to vary the degree of branching of polymers derived from an ABB 0 type monomer by changing the reaction conditions.In this paper, we focus on the synthesis of polyamides with different degree of branching derived from an ABB 0 type monomer by using different condensation agents. The properties and structure of the polyamides derived from different reaction conditions were investigated. The end m...

Positive-type Alkaline Developable Photosensitive Branched Polyamides with Low Degree of Branching and Diazonaphthoquinone as a Photosensitive Compound

“…16 Synthesis of Branched Polyamides with Low Degree of Branching: Method A with DBOP (2a). To a solution of 1 (2.928 g, 0.013 mol) in the 60 mL of NMP, DBOP (5.140 g, 0.0134 mol) and TEA (1.83 mL) were added.…”

“…[6][7][8][9][10][11][12][13][14][15] We recently reported that the branched polyamides with low degree of branching (low DB) approximately 0.2 prepared by the polycondensation of a ABB 0 type monomer, 4-(2,4-diaminophenoxy) benzoic acid. 16 The polycondensation of ABB 0 type monomer, in which A is a carboxyl group and B and B 0 are amino groups with different circumstance, provides the polyamides with relatively lower degree of branching. The advantage of the branched polyamides with low degree of branching is not only good solubility for aprotic polar solvents such as dimethylformamide (DMF), N,N-dimethyl acetamide (DMAc) and 1-methyl-2-pyroridone (NMP), but also high tensile strength of the casting films.…”

Hyperbranched poly(ether sulfone)s: preparation and application to ion-exchange membranes

“…Recently, we prepared hyperbranched polymers, such as aromatic polyamides, [5][6][7][8][9][10][11][12][13][14][15][16][17][18] polyimides, [19][20][21][22][23][24]15,25 polyesters, 26 polysiloxanes, 27,28 poly(benzoxazole)s, [29][30][31][32][33] poly(triphenylamine), 34 PES [35][36][37][38][39] and poly (siloxysilane), [40][41][42][43][44][45] from AB 2 type monomers, and investigated their mechanical properties. Moreover, to synthesize polyamides, 46 polyimides 47,23,48 and polyphthalocyanines, [49][50][51]…”

Synthesis, optical and electrochemical properties of new hyperbranched poly(triphenylamine amide)s

“…Dendritic polymers have received considerable attention due to their unique chemical and physical properties [1][2][3][4][5][6][7]. Hyperbranched polymers show similar properties to those dendrimers, such as low viscosity, high solubility in organic solvents, and lack of significant entanglement in the solid state.…”

“…This is advantageous over the multi-step synthesis of dendrimers because of the rapid production in large quantities. It is also well known that the properties of the dendritic polymers depend on terminal functional groups in addition to backbone structure [1][2][3][4][5][6][7]. Therefore, the properties of dendritic polymers can be tuned to some extent by the chemical modification of end functional groups [1][2][3][4][5][6][7].…”