Synthesis and characterization of new diacid monomers and poly (ester-imide) s: a study of thermal property relationship and solubility
Abstract
Two dicarboxylic acids [2,2'-(((4-hydroxyphenyl) methylene) bis (3-Bromo-4,1- phenylene)) bis (1,3 dioxoisoindoline 5 carboxylic acid)) and 2,2 '(((2,4dichlorophenyl) methylene) bis (4,1-phenylene)) bis (1,3-dioxoisoindoline-5-carboxylic acid)] were madeby the reaction of pyromellitic anhydride (PMDA) with diamine in asolvent of gpyridine/glacial acetic acid at refluxing temperature.The organization of the diacid monomers is defined by FTIR and 1H-NMR spectroscopy.The sequence ofnew poly (ester-imide) s are arranged of two di acidsand aromatic diols: [Bis (4hydroxyphenyl) 2 furelmethaneand 4,4'((1,4phenylene (methanylyidene)) bis (azanylylidene)) diphenol] by employing the polycondensation in the company of the dibutyltine dilaurate as a catalyst. The PEIs were defined by FTIR, 1HNMR, and TGA. Poly (ester-imide) s showed excellent solubility in polar aprotic solutions because of the existence of flexible groups in the polymer backbone. Furthermore, they displayed better thermal constancy, and the heat at that 10% loss of weight happened about700 to 800°C.
Keywords
pol (esters-imide), Diols, pyromellitic anhydride (PMDA) polycondensation, dicarboxylic acid
Introduction
Aromatic polyamide (Zhang et al., 2007) is one of the highly beneficial kinds of polymers that have high performance. These substances were broadly employed in aerospace productions, electronics, automotive, and electrical (Denton et al., 1985). Polyimides are utilized as films, fibres, plastics, foams, coatings, and adhesives (Köytepe, Paşahan, Ekinci, Alıcı, & Seçkin, 2008). The manufacturing procedure for a polymeric substance needs which the polymers are soluble in organic solutions for a casting process or melted lower than their decomposition temperature for a molding extrusion procedure. Aromatic polyamides were unsolvable and cannot be fused and hard to manufacture into wanted objects. Most important prepared works have been made to develop the processability without lessening thermal constancy (Ghosh & Mittal, 1996).
Nevertheless, entirely aromatic polyimides have usually insufficiencies solubility, processability, melting or softening behaviour. So, a high volume of study focused on the exploration of new solvable polyimides in entirely iridized shape. Many methods to soluble polyimides containing the combination of malleable links, immense constituents or asymmetric noncoplanar units have been improved (Hamciuc & Hamciuc, 2008). The existence of ester groups into the macromolecular series of a polyimide enhances the solubility that links the benefit of high-temperature stability with the easiness of processability. The general approaches utilized in making of the poly(ester imide) s are (a) polycondensation between trimellitic acid or its derivative with a diamine and a diol (Shen, 1982)(b) reaction between a dicarboxylic acid including an imide ring with Diol (Maiti & Das, 1981)(c) polycondensation of a dianhydride comprising ester group with a diamine (Malvaney, 1986) (d) reaction from N-(4-carboxyphenyl)-4-acetoxy phthalimide and 4-acetoxy benzoic acid (Kricheldorf, Schwarz, & Nowatzky, 1989)(e) pyrolytic polymerization of monomers including pre-formed ester links (Kurita, Mikawa, Koyama, & Nishimura, 1990)(f) direct polycondensation between a 4-carboxy-N-(p- or m-hydroxyphenyl phthalimide, diacid, and bisphenol A in the existence of an immediate concentration agent (Li, Jung, Liang, & Chang, 1995). This research including synthesis new poly (ester-imide) (PEIs) from reaction diols such as (M1, M2,) with diimide-dicarboxylic acid such as compounds (M5, M6,) in the existence of dibutyltin dilaurate as Catalyst. Means of FTIR and 1H-NMR spectroscopy ultimately defined the resulted monomers and polymers, solubility and thermal stability also studied.
Materials and Methods
Preparation of monomers
Bis (4-hydroxyphenyl) 2-fuel methane) (M1)
A 0.1M solution of H2SO4 in methanol (60 %: 40%), phenol (2gm), (21mmol) and Furfural (1.5gm), (12mmol) are joined, and the blend was refluxed at (120) OC for ten hours and the continuous moving. After completing the reaction, the solvent was detached under vacuum (Sarma & Baruah, 2004). The produce was (71%) of brown crystals, m.p= (80°C) crystals.
4,4'((1,4phenylene(methylidene)) bis(azanylylidene)) diphenyl(M2)
This monomer was made by the concentration of one molecule of Terephthalaldehyde (1.34 gm) (10mmol) with two molecules of P-Amino phenol (2.2 gm) (20 mmol) in methanol (5) ml, by boiling defined the blend reflux by (120) °C for 3 hours. Sediment is purified and recrystallized from methanol and desiccated in a vacuum desiccator's (Jarrahpour, Jalbout, Rezaei, & Trzaskowski, 2006)to give 2.5 gm (79%wt) of extremely light yellow crystals m.p 205-210oC.
4,4'-((2,4-chlorophenyl) methylene) aniline (M3)
The 0.1M solution of H2SO4 in methanol (60%:40%), 1,3dichloroaniline (2gm) (21mmol) and 4-Bromobenzaldehyde (1.5 gm) (12mmol) are joined, and the blend was refluxed at 120ᵒC for 10 hours with the continuous stirring. After completing the reaction, the solution was distanced under vacuum (Sarma & Baruah, 2004). The product is (71%) of brown crystals, m.p= (230°C) crystals.
The monomer 4-(bis (4-amino-2-bromophenyl) methyl) phenol (M4) made by a similar method that (M3) are shaped, but by utilizing materials such as 3-bromoaniline and 4-hydroxy benzaldehyde in existence of a mixture of methanol and H2SO4 as a catalyst.Table 1 Shows as,
No |
Monomer |
Substance |
Color |
Yield% |
|
---|---|---|---|---|---|
1 |
DCPMDA |
2,4dichlorobenzaldehyde 1.5gm(18mmol) |
Aniline 2gm(5mmol) |
yellow |
51% |
2 |
BABPMP |
4-hydroxybenzaldehyde 2gm(11mmol) |
2-Bromoaniline 2.5gm(26mmol) |
Orange |
76% |
Synthesis of dicarboxylic acids
Synthesis of 2,2'-(((2,4-dichlorophenyl) methylene) bis (4,1-phenylene)) bis (1,3-dioxoisoindoline-5-carboxylic acid) [M5]
In 250 mL round-bottomed flask are appended (3.84gm) (20 mmol) of pyromellitic anhydride, (2gm) (4mmol) of DCPMDA, acetic acid (80) mL and pyridine (3:2), and a moving bar at 25 C for 24 hours. The solution was detached under decreased pressure, and the remainder is melted in 100 mL. Later, concerted hydrochloride (5) ml was appended. The solvent is mixed till yellow sediment was made, and sediment was purified and desiccated (M5) (Faghihi & Hagibeygi, 2007).
The diacid 2,2'- (((4-hydroxyphenyl) methylene) bis(3-bromo-4,1-phenylene)) bis (1,3-dioxoisoindoline-5-carboxylic acid) (M6) made in similar method above using materials, BABPMP, pyromellitic anhydride acetic acid and pyridine. Table 2 Shows as,
No |
Diacids |
Color |
Yield% |
M.P/ ₒc |
---|---|---|---|---|
1 |
M5 |
yellow |
51% |
392oC |
2 |
M6 |
Orange |
76% |
395oC |
Preparation of poly (ester imide) s
Dihydroxy monomer and Di-Carboxylic acid, as seen in Table 3 are blended at 120ᴏC under continuous moving. When the acid dissolute that contain imide in Dihydroxy monomers, the dibutyltin dilaurate catalyst (0.15 wt. (%)) is joined, and the temperature raised to 160ᵒC for one hour. The constituents were desiccated under vacuum (H.Guimaraesa & M.Brioudea, 2007). Figure 1andFigure 2 are as following:
Colour |
Product (wt%) |
Dihydroxy gm |
Dihydroxy gm |
Monomers |
Poly |
||
---|---|---|---|---|---|---|---|
/mmol |
/mmol |
diacid |
Dihydroxy |
(ester-imide)s |
|||
Black |
94% |
1.1 gm |
2.4 gm |
M1 |
M5 |
P.E1 |
|
Yellow |
75% |
1gm |
1.2gm |
M2 |
M6 |
P.E2 |
Results and Discussion
The FTIR spectra of (M1) as displayed inFigure 3with its absorption band: (Silverstein, Webster, & Kiemle, 2005)
(C=C)ar. 1590; (C-H)ar. 3116 (OH) 3394;(C-H)ali 2947 (C-O) 1218 cm-1
The FTIR spectra of (M2) as revealed in Figure 4with its absorption band:
(C=C) ar.1589; (C-H)ar.3109;(OH) 3425;(C-H)ali.2839 ;(C-N) 1311;(C=N)1645 Cm-1
The FTIR spectra of (M3) as displayed in Figure 5with its absorption band:
(C=C) ar. 1689; (C-H)ar.3170; (NH2)3417;(C-N)1270;(C-O)1130;(C-Br)633 cm-1
The FTIR spectra of (M4) as displayed in Figure 6with its absorption band:
(C=C) ar.1650; (C-H)ar. 3093; (NH2) 3394 ; (C-N)1288 ; (C-Cl ) 771cm-1
The FTIR spectra of (DCPMDA) as displayed inFigure 7with its absorption band:
(C=C)ar.1604; (OH) 3200 ; (C-N)1296 ; (C-O)1172; (C=O) 1692 ; (C-Cl) 750 cm-1
(DCPMDA) Spectrum is displayed in Figure 8identifies the subsequent chemical alterations;
DMSO= δ (2.486) ; CH= δ (5. 838) (1H); Ar-H group= δ (7.712 -8.982); COOH(2H) = δ (13.536) ppm
FTIR spectra of (BABPMP) as displayed in absorption band:
Figure 9 shows,
(C=C) ar. (1600) ; (NH2) 3417; (C-N) 1270; (OH) 3550; (C-O)1130 ; (C=O) 1700 ; C-Br = 633 cm-1
(BABPMP) Spectrum is displayed in Figure 10 identifies the subsequent chemical alterations;
DMSO = δ (2.476); CH = δ (5.085); Ar-H group = δ (7.495-8.7 05); COOH = δ (12.014); OH = δ (4. 731) ppm
Synthesis of poly (ester amide) s [PE1- PEI2]
This part of the study employed polycondensation way for the preparation of chains of new polyester from the immediate polycondensation reaction diacids (DCPMDA, BABPMP) with new diverse aromatic di hydroxyl monomer [M1, M2], correspondingly by utilizing the dibutyltin dilaurate as catalyst (0.15 wt (%)). These polymers had a soft section like methylene unit, and pyridine heterocyclic ring in key series to develop solubility in organic solutions. These polyesters are defined through 1H-NMR spectra. Figure 11 andFigure 12 are as follows,
poly(ester imide) s [PEI1-PEI2] Characterization
1H-NMR spectrum of (PEI1), is displayed Figure 13 identifies the subsequent chemical changes; DMSO = δ (2.488-2.529) ; CH = δ (0. 780-1.539); Ar -H group = δ (7.789 -8.255); OH = δ(4. 731) ppm
(PEI2) Spectrum is displayed inFigure 14 identifies the subsequent chemical alterations: DMSO = δ (2.147); CH = δ (7.789); Ar-H group = δ (8.025-8.255); OH = δ (4. 731) ppm
The solubility of poly (ester imide) s
The solubility of polyesters PEI1-PEI4 is qualitatively examined in organic solutions. The outcomes were briefed inTable 4 . The way which tries to improve the process capabilities and solubility are through presenting immense groups, elastic connections, or molecular asymmetry into the polymer backbones. The current study, the supplement of immense pendant groups in polymer backbone may not offer an improved solubility due to reduced filling density and crystallinity but similarly would report a rise in Tg by limiting the segmental mobility. Among the main goals of the study is to produce polyesters with better solubility (Zhao, Wang, Chen, & Zhu, 2009). Solubility is examined as (0.01gram) of the polymeric specimen in (2ml) of a solution. All of the recently prepared polyesters have well solvable.
Poly (ester-imide)s |
Solvent |
|
---|---|---|
PEI2 |
PEI1 |
|
++ |
- + |
pyridine |
++ |
++ |
CHCl3 |
-+ |
-+ |
CH2Cl2 |
++ |
++ |
NaOH |
-+ |
+++ |
H2SO4 |
++ |
++ |
HNO3 |
++ |
+++ |
Acetone |
++ |
++ |
Benzene |
++ |
++ |
DMF |
++ |
-+ |
DMSO |
+++ |
-+ |
THF |
1- Complete Soluble(+++); 2- Soluble at 25 C (++); 3- Semi-complete Soluble (+-)
Aromatic poly (esterimide) s |
DT/°C |
DT/°C |
DT/°C |
DT/°C |
T50% |
Residue at oC800 |
Char % at |
---|---|---|---|---|---|---|---|
PEI1 |
200 |
400 |
554 |
800 > |
790 |
49% |
72% |
PEI2 |
400 |
600 |
----- |
800 > |
789 |
58% |
79% |
Poly (ester-imide)s thermal analysis
Thermogravimetric Analysis includes defining variations mass. It is generally employed to investigate degradation temperatures, absorbed content of constituents, levels of inorganic, and organic parts enclosed in a material and analyses solvent residues (Moukhina, 2012). It utilizes a delicate electronic balance from that the sample is suspended in a furnace organized by a temperature programmer. The thermal characteristics of four examples of this polyester were examined through thermogravimetric analysis (TGA) in Argon atmosphere temperature degree of 10°C/min and the yields like Ti, Top, Tf, T50 %, % sediment at 800 oC, and char produces at (500) °C is briefed inTable 5. The temperatures of 50% loss of weight of (PEI1-PEI2) as a normal reference for thermal constancy of polymers are all from 700 to 800°C, char produces (PEI1-PEI2) at 500°C are 58% until79% in Argon atmosphere, that refers to that they can endure extreme temperature resistant needs as some particular substances in modern aerospace. Weight residue of (PEI1-PEI2) at (800) °C are the maximum than Aromatic polyester of this chain, (49% until 58%).Figure 15 and Figure 16 are as following:
Conclusion
The current study has positively made new dicarboxylic acid 2,2'-(((4-hydroxyphenyl) methylene) bis (3-Bromo-4,1-phenylene)) bis (1,3 dioxoisoindoline 5 carboxylic acid)) 2,2'(((2,4dichlorophenyl) methylene) bis (4,1-phenylene)) bis (1,3-dioxoisoindoline- 5-carboxylic acid), Diamine [4,4'-((2,4-chlorophenyl) methylene) aniline and 4- (bis (4-amino-2-bromophenyl) methyl) phenol, and diols. There is an imide group linked. These polymers have high solubility because of the presence of the ester in the polymer that male (PEIs) have high ability to attract with processed plastics that may be subject of additional studies.