Interfacial Polycondensation Method Research Articles

Facile Synthesis of Processable Semi-aromatic Polyamide Containing Thioether Units

A series of processable semi-aromatic polyamides containing thioether units have been developed. They were synthesized through the reaction of 4,4’-bis(4-chloroformylphenylthio)benzene (BPB-DC) and aliphatic diamine by the method of interfacial polycondensation. These polyamides had excellent thermal properties with glass transition temperatures (Tg) of 124–137.9°C, melting temperatures (Tm) of 306.4–324.1°C and initial degradation temperatures (Td) of 409.5–437°C. They had wider processing windows than traditional semi-aromatic polyamides and can be processed by the melting method. They had better tensile strengths of 61.2–73.7 MPa, low-temperature mechanical properties, low water absorption of 0.17%–0.23%, low dielectric constants of 3.47–3.66 at 100 kHz and better melt flowability properties of 37.3 to 164.4 Pa. s, 48.2 to 281.7 Pa. s and 58.3 to 486.7 Pa. s at different shear rates, respectively. Additionally, these polyamides showed good corrosion resistance, they did not dissolve in solvents such as NMP, DMSO, hydrochloric acid (6 mol/L), H3PO4 and solution of NaOH (1 mol/L) etc.

Synthesis and Characterization of Poly(ethylene terephthalamide/hexamethylene terephthalamide)

Semiaromatic poly(ethylene terephthalamide/hexamethylene terephthalamide) copolymer (PA2T/6T) was synthesized through the reaction of terephthaloyl chloride, 1,6-hexane diamine and 1,2-ethylene diamine by the method of interfacial polycondensation. The inherent viscosities of the resultant copolymers prepared with optimum synthesis conditions were 0.40–0.80 dL/g. The chemical structures of the copolymers were characterized by FT-IR and 1H-NMR. These copolymers had excellent thermal properties with melting temperatures (Tm) of 340–380°C and initial degradation temperatures (Td) of 390–440°C. The copolymers had wider processing temperature range than poly(hexamethylene terephthalamide) (PA6T), especially the copolymer which contained 60% 2T unit (2T mol% = 60%). At the same time, the ethylene diamine and hexane diamine is cheap which can decrease the costs of the materials. It suggests PA2T/6T is a promising heat resistant and processable engineering plastic.

Preparation, characterization and thermal properties of micro-encapsulated phase change materials

In this study, a novel microencapsulated phase change material (palmitic acid@AlOOH) was prepared using an in situ emulsion interfacial poly-condensation method. The resulting colloidal-sphere microcapsules, with diameter around 200nm, are of core-shell microstructures. Characteristic peaks of both palmitic acid and AlOOH can be observed during their IR spectrum characterization. According to the TGA examinations, the encapsulated ratios of palmitic acid (PA) to PA@AlOOH are 52%, 57% and 69%. The DSC results indicate that melting temperatures of the microencapsulated PCMs are remarkably 50°C lower than those of pristine PA, which might originate from the strong interface interactions between the core and shell of PA@AlOOH. The thermal storage capabilities of the microcapsules are also tested. The method and mechanism of this study can be extended to design other organics@inorganics PCMs with different core-shell structured compositions.

Facile Synthesis of Processable Semiaromatic Polyamides Containing Thioether Units

Semiaromatic polyamides containing thioether units were synthesized through the reaction of 4,4′-thiodibenzoyl chloride (TDC) and diamine by the method of interfacial polycondensation. The inherent viscosities of the resultant polyamides prepared with optimum synthesis conditions were 1.08–1.26 dL/g. These polyamides had excellent thermal properties with glass transition temperatures (Tg) of 119.8–190.1 °C, melting temperatures (Tm) of 281.4–355.5 °C, and initial degradation temperatures (Td) of 433.5–466 °C. They had wider processing windows than traditional semiaromatic polyamides. At the same time, they had better tensile strengths of 62.1–86.5 MPa, better low-temperature mechanical properties, lower water absorption, lower dielectric constants of 3.16–3.81 at 100 kHz, and better melt flowability properties. The results suggest that these semiaromatic polyamides containing thioether units [poly(hexanelene 4,4′-thiodibenzoamide) (PA-6), poly(octanelene 4,4′-thiodibenzoamide) (PA-8), and poly(decanelene 4,4′-thiodibenzoamide) (PA-10)] represent a promising type of heat-resistant and processable engineering plastic.

Synthesis and characterization of new aliphatic polyesters containing dihydronaphthofuro[3,2-d]furan moiety

A dihydronaphthofuro[3,2-d]furan containing diol monomer, viz., 2,13-dihydroxy[7a,14c] dihydro naphtho[2,1-b]naphtho[1′,2′:4,5]furo[3,2-d] furan (DDNF) was synthesized in high yield and purity through the condensation of commercially available 2,7-dihydroxynaphthalene with glyoxal at room temperature. It was used as a new monomer for the synthesis of a series of novel dihydronaphthofuro-containing aliphatic polyesters by interfacial polycondensation method. Optimal conditions for polyesterification were obtained via study of the model compounds. The diol monomer and model compound were fully characterized by infrared, nuclear magnetic resonance (NMR), mass spectroscopies, and elemental analysis. Polyesters derived from DDNF and four aliphatic diacid chlorides had inherent viscosities ranging from 0.36 to 0.51 dL g−1. The chemical structure of the polymers was characterized by Fourier transform infrared, NMR spectroscopies and elemental analysis. The physical properties of the polymers were studied. The glass transition temperature was in the range of 89–118 °C. All the new polymers showed good thermal stability and very good solubility in most organic solvents.

Synthesis and characterization of new aromatic polyesters based on 8,16-methano-16H-dinaphtho[2,1-d:1′,2′-g][1,3]dioxocin-2,14-diol

The bisphenol monomer containing dinaphthodioxocin group viz., 8,16-methano-16H-dinaphtho[2,1-d:1′,2′-g][1,3]dioxocin-2,14-diol (MDDD) was synthesized from commercially available 2,7-dihydroxynaphthalene and malonaldehydetetramethyl acetal and fully characterized by FT-IR, 1H, 13C NMR and mass spectroscopies. A series of new aromatic polyesters was synthesized by phase transfer-catalysed interfacial polycondensation or high temperature solution polymerization method. Optimal conditions for polyesterification were obtained via study of the model compounds. These polyesters were characterized by spectroscopic technique, viscosity measurement, solubility, thermal stability, DSC, and elemental analysis. Inherent viscosities and number average molecular weights (Mn) of polyesters were in the range 0.33–0.74 dl/g and 13,130–38,000 (Gel Permeation Chromatography, polystyrene standard). All of the new polymers show very good solubility in polar aprotic solvents and could be cast into transparent, flexible and apparently tough films. The glass transition temperature (Tg) of polyesters was in the range of 152–289 °C. Polyesters derived from MDDD and eight aromatic diacid chlorides did not show any weight loss below 330 °C and retained 23–43% weight at 600 °C. The temperature at 10% weight loss (T10), determined from thermogravimetric analysis of polyesters, was in the range 420–434 °C indicating their good thermal stability.

Synthesis and characterization of new aliphatic polyesters containing methanodinaphtho[1,3]dioxocin part

AbstractA novel dinaphthodioxocin‐containing diol monomer, 8,16‐methano‐16H‐dinaphtho[2,1‐d:1′,2′‐g][1,3] dioxocin‐2,14‐diol (MDDD) was synthesized in high yield and purity through the condensation of 2,7‐dihydroxynaphthalene with malonaldehydetetramethyl acetal at room temperature. It is used as a new monomer for the synthesis of a series of novel dinaphthodioxocin‐containing aliphatic polyesters by interfacial polycondensation method. The new diol monomer was fully characterized by IR, NMR, mass spectroscopies, and elemental analysis. Optimal conditions for polyesterification were obtained via study of the model compounds. Polyesters derived from MDDD and four aliphatic diacid chlorides had inherent viscosities ranging from 0.26 to 0.38 dL/g. The chemical structure of the polymers was fully characterized by IR, NMR spectroscopies, and elemental analysis. The physical properties of the polymers were studied. All the new polymers show good thermal stability and very good solubility in most organic solvents. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Synthesis and characterization of novel optically active poly(ester-imide-imine)s

Abstract N,N´-(3,3´,4,4´-Benzophenonetetracarboxylic)-3,3´,4,4´-diimido-di-Lamino acids (1a-1d) and N,N´-pyromelliticdiimido-di-L-amino acids (2a-2d) are prepared from the reaction of 3,3´,4,4´-benzenetetracarboxylic-3,3´,4,4´- dianhydride or pyromellitic dianhydride with the corresponding L-amino acids in a solution of glacial acetic acid/pyridine (3:2) at refluxing temperature. 4-(4-((4- Hydroxyphenylimino)methyl)benzylidene amino) phenol (3) is prepared from 4- amino phenol and terephthaldialdehyde in refluxing ethanol. Interfacial polycondensation method was used to prepare the corresponding polymers (PEII1-8) in two immiscible solvents (water/dichloromethane). The resulting poly(esterimide- imine)s (PEIIs) having good inherent viscosities (0.13-1.25 dl g-1), optical activity and thermal stabilities is obtained in high yields.

Microencapsulation of butyl stearate as a phase change material by interfacial polycondensation in a polyurea system

For the last 20 years, microencapsulated phase change materials (MicroPCMs), which combine microencapsulation technology and phase change material, have been attracted more and more interest. By overcoming some limitations of the PCMs, the MicroPCMs improve the efficiency of PCMs and make it possible to apply PCMs in many areas. In this experiment, polyurea microcapsules containing phase change materials were prepared using interfacial polycondensation method. Toluene-2,4-diisocyanate (TDI) and ethylenediamine (EDA) were chosen as monomers. Butyl stearate was employed as a core material. The MicroPCMs’ properties have been characterized by dry weight analysis, differential scanning calorimetry, Fourier transform IR spectra analysis and optical microscopy. The results show that the MicroPCMs were synthesized successfully and that, the phase change temperature was about 29 °C, the latent heat of fusion was about 80 J g −1, the particle diameter was 20–35 μm.

Synthesis and characterization of new optically active poly(azo-ester-imide)s via interfacial polycondensation

N,N'-Pyromelliticdiimido-di-L-amino acids (1a-1d) were prepared from the reaction of pyromellitic dianhydride with the corresponding L-amino acids in a solution of glacial acetic acid/pyridine (3:2) at refluxing temperature. 4,4'-sulfonyl bis(4,1-phenylene) bis(diazene-2,1-diyl) diphenol, 4,4'-oxy bis(4,1-phenylene) bis(diazene-2,1-diyl) diphenol and 4,4'-methylene bis(4,1-phenylene) bis(diazene-2,1-diyl) diphenol, were prepared from 4,4'-diamino diphenyl sulfone, 4,4'-diamino diphenyl ether, 4,4'-diamino diphenyl methane, sodium nitrite and phenol following the general procedure of diazo coupling. Interfacial polycondensation method was used to prepare the corresponding poly(azo-ester-imid)s (PAEI(1-12)) in biphasic solution of water/dichloromethane. The resulting polymers (PAEIs) have been obtained in high yields having good inherent viscosities (0.32-0.57 dl g(-1)), optical activities and thermal stabilities.

Synthesis and characterization of new poly(azomethine ester)s having phenylthiourea units

New polyesters having azomethine and phenylthiourea groups in the polymer backbone were synthesized by interfacial polycondensation method. The dihydroxy monomer N-(4-hydroxy-3-methoxybenzal) N′-(4′-hydroxyphenyl)thiourea was condensed with six diacid chlorides: terephthaloyl, isophthaloyl, azeloyl, suberoyl, pimeloyl and adipolyl chlorides. The resulting polyesters were characterized by viscosity, IR, NMR and TGA analysis. The wholly aromatic poly(azomethine ester) derived from terephthaloyl chloride when blended with polyaniline/NH 4OH, polyaniline/HCl and pure polyaniline shows conductance in the range 3.2 × 10 −3–0.91 × 10 −1 S cm −1.

Studies on Photoreactive Polyesters Containing α, β-Unsaturated Carbonyl Group in the Main Chain

A series of polyesters containing °-unsaturated carbonyl group in the main chain was synthesized from 1,3-bis(4-hydroxyphenyl)propenone and 3-(4-hydroxy-3-methoxyphenyl)-1-(4-hydroxyphenyl)propenone with various aliphatic and aromatic acid chlorides by an interfacial polycondensation method using a phase transfer catalyst. The structure of the synthesized monomers and polyesters was confirmed by IR, 1H NMR, 13C NMR and UV spectroscopy. These polyesters were studied for their thermal and photochemical properties. The thermal properties of polyesters were evaluated by thermogravimetric analysis and differential scanning calorimetry. The polyesters synthesized from aromatic acid chlorides have shown higher thermal stability than the polyesters from aliphatic acid chlorides. Moreover, the results revealed that the polyesters bearing methoxy substituent on the phenyl ring group possess lower thermal stability than non-substituted polyesters. The photoreactive property of the polyesters was studied by UV and IR spectrophotometer. It is observed that on exposure to UV light the polymers undergo photocrosslinking reaction. The photocrosslinking proceeds through the dimerization of olefinic chromophore via 2 + 2 cycloaddition reaction.

Random multiblock poly(ester amide)s containing poly(L‐lactide) and cycloaliphatic amide segments: Synthesis and biodegradation studies

AbstractNovel multiblock poly(ester amide)s containing poly(L‐lactide) and cycloaliphatic amide segments were synthesized from telechelic oligomer of α,ω‐hydroxyl terminated poly(L‐lactide), 1,3‐cyclohexylbis(methylamine), and sebacoylchloride by the “two‐step” interfacial polycondensation method. The blocky nature of PEAs was established by FTIR and 1H NMR spectroscopies. The effect of relative content of ester and amide segments on the crystallization nature of PEAs was investigated by WAXD and DSC analyses. PEAs having lower content of PLLA, PEA 1 and PEA 2, showed a crystallization pattern analogous to polyamides, whereas PEA 3, having higher content of PLLA, showed two crystalline phases characterized by polyester and polyamide segments. Random nature of PEAs was observed from single Tg values. Biodegradation studies using the enzyme lipase from Candida Cylindracea showed higher degradation rate for PEA 3 than that for PEA 1 and PEA 2. FTIR, 1H NMR, and DSC analyses of the degraded products indicated the involvement of ester linkages in the degradation process. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3250–3260, 2006

Microencapsulation of n-Hexadecane as a Phase Change Material in Polyurea

For thermal energy storage application, polyurea microcapsules about 2.5 mum in diameter containing phase change material were prepared using interfacial polycondensation method. in the system droplets in microns are first formed by emulsifying an organic phase consisting of a core material ( n-hexadecane) and an oil-soluble reactive monomer, toluene-2, 4-diisocyanate (tdi), in an aqueous phase. by adding water-soluble reactive monomer, diamine, monomers tdi and diamine react with each other at the interface of micelles to become a shell. ethylenediamine (eda), 1, 6-hexane diamine (hda) and their mixture were employed as water-soluble reactive monomers. the effects of diamine type on chemical structure and thermal properties of the microcapsules were investigated by ft-ir and thermal analysis respectively. the infrared spectra indicate that polyurea microcapsules have been successfully synthesized; all the tg thermographs show microcapsules containing n-hexadecane can sustain high temperature about 300 degreesc without broken and the dsc measurements display that all samples possess a moderate heat of phase transition; thermal cyclic tests show that the encapsulated paraffin kept its energy storage capacity even after 50 cycles of operation. the results obtained from experiments show that the encapsulated n-hexadecane possesses a good potential as a thermal energy storage material.

Synthesis and characterization of aromatic polyesters and copolyesters from 4,4′‐(1‐hydroxyphenylidene)diphenol and 4,4′‐(9‐fluorenylidene)diphenol

AbstractTwo isophthalic polyesters from 4,4′‐(1‐hydroxyphenylidene)diphenol (BAP/ISO) and 4,4′‐(9‐fluorenylidene)diphenol (BF/ISO), and three different copolyesters containing 75, 50, and 25 mol % of BAP/ISO were synthesized by interfacial polycondensation. This preparation method yielded polymers and copolymers that produced flexible and transparent films when they were cast from solution. Proton NMR spectrometry studies showed that the isophthalic copolyesters were obtained as random copolymers with differences in comonomer composition no larger than 2.5 mol % with respect to the expected compositions. Wide‐angle X‐ray diffraction measurements indicated that all the polyesters and copolyesters were amorphous. The copolyesters showed amorphous patterns with maxima that fell between those of the polyesters. It was also found that thermal properties such as glass‐transition temperature, onset of decomposition temperature, thermal stability, dynamic mechanical storage modulus, and maximum on the α‐transition of the damping factor tan δ of BF/ISO were higher than those of BAP/ISO. The values of these thermal properties in the copolyesters fell between those of the polyesters and were dependent on the amounts of BF/ISO and BAP/ISO present in the copolyester in a linear fashion. Therefore, the thermal properties of a given copolyester can be predicted directly from the comonomers' composition. Overall, it shows that the interfacial polycondensation method is suitable to obtain these copolyesters in a controlled manner and that their properties can be tailored to be between those of the homopolyesters. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2515–2522, 2002

Microencapsulation of octadecane as a phase-change material by interfacial polymerization in an emulsion system

Microcapsules containing phase-change material for thermal adaptable fiber application were synthesized and characterized. The microcapsules of about 1 μm in diameter were prepared using an interfacial polycondensation method with toluene-2,4-diisocyanate (TDI) and diethylenetriamine (DETA) as monomers in an emulsion system. Octadecane was used as a phase-change material and NP-10 which is nonionic surfactant, was used as an emulsifier. To investigate the reaction ratio of monomers, microcapsules were synthesized with 3 g TDI and 0–4 g DETA. Polyurea microcapsules were formed not only by reaction with TDI and DETA, but also by reaction of TDI with hydrolyzed TDI at the interface. TDI was reacted with DETA in the weight ratio of 3:1. NP-10 was reacted with TDI to form urethane. The microcapsules containing octadecane showed a phase change of octadecane at 29–30 °C. The core content measured using the heat of fusion of octadecane was less than that calculated. The efficiency of octadecane encapsulation increased as the core content decreased.

Preparation of amorphous poly(ethylene terephthalate) from U‐polymer via a copolymerization process

AbstractU‐Polymer, a kind of polyarylate, was synthesized by interfacial polycondensation method with terephthaloyl chloride (TPC), isophthaloyl chloride (IPC), and bisphenol A (BPA) as raw materials. The structure of the U‐Polymer was characterized by IR and 1H–NMR spectra. Then, an amorphous poly(ethylene terephthalate) (APET) was prepared with the introduction of the U‐Polymer to the PET sequence to improve thermal and mechanical behaviors of PET via the polymerization process. The structure and property of the APET were characterized by DSC and DMA. The results showed that the APET exhibits amorphism, transparency, higher glass‐transition temperature (Tg), and higher storage modulus than that of PET. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1653–1657, 2001

Morphology and structure of microcapsules prepared by interfacial polycondensation of methylene bis(phenyl isocyanate) with hexamethylene diamine

Polyurea microcapsules containing 2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl) acetamide as the active agent were prepared by the method of interfacial polycondensation with methylene bis(phenyl isocyanate) as the multifunctional isocyanate, hexamethylene diamine as the diamine, and anionic sodium lignin sulphonate (SLS) as the emulsifying agent. The internal structure and morphology of the microcapsules were examined with transmission electron microscopy. The microcapsules had a micro-reservoir structure in which the wall extended well into the core and the active agent was accommodated by the micro-reservoirs, distributed uniformly throughout the entire volume of a microcapsule. Based on the observed morphology, permeability of the water soluble monomer in the polyurea film and its solubility in the oil phase have a significant effect on the morphology and microstructure of the microcapsules. The multivalent salt, calcium chloride, plays a significant role in stabilizing the microcapsule structure, by interacting with the anionic surfactant SLS, and physically crosslinks the SLS chains, by interacting with the negatively charged carboxylic and phenolic groups, with subsequent phase separation of the physically crosslinked chains to form a concentrated gel phase. This gel phase encompasses the microcapsule, increases the stability, and modifies its release behaviour.

Influence of chemical structure of isophthaloyl dichloride and aliphatic, cycloaliphatic, and aromatic diamine compound polyamides on their chlorine resistance

The influence of the chemical structures of the polyamides on chlorine resistance was studied by measuring their chlorine uptake rates. They were prepared from isophthaloyl dichloride and aliphatic, cycloaliphatic, or aromatic diamines by the solution or interfacial polycondensation method. This study showed that the chlorine resistance was dependent on the chemical structures of the diamine compounds used in the synthesis of the polyamides. We concluded that the polyamides comprising the diamine components with the following chemical structures had higher chlorine resistance: aliphatic or cycloaliphatic diamine compounds with a secondary amino group, aliphatic or cycloaliphatic diamine compounds with a shorter methylene chain length between end amino groups, and aromatic diamine compounds with methyl or chlorine substituents at the ortho position of the amino groups. Chlorine resistance is related to the basicity of the aliphatic and aromatic diamines used. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 201–207, 2000

Synthesis and Characterization of Polyphosphonates having Azomethine Linkages

Two bishydroxy azomethine monomers were synthesized and reacted with dichloro-phenyl phosphine oxide by the interfacial polycondensation method using a phase transfer catalyst at 0°C. The polymers were characterized by IR, 1H-NMR, 31P-NMR, elemental analyses and X-ray diffraction study. These polymers are soluble in chlorinated aliphatic hydrocarbon solvents, such as CH2Cl2, CHCl3 as well as polar aprotic solvents such as DMF, DMAC, NMP, DMSO. Thermal and flammability studies were carried out by TGA, DTA and limiting oxygen index (LOI) measurements. The polymers are self-extinguishing and begin to lose weight at around 290°C in air.