Abstract:A series of new polyarylates bearing cardo xanthene groups were synthesized by phase-transfer-catalyzed interfacial polycondensation of 9,9-bis[4-(4-chloroformylphenoxy)phenyl]xanthene with various bisphenols containing the isopropylidene, hexafluoroisopropylidene, 1-phenylethylidene, diphenylmethane, cyclohexane, and xanthene structures. High-molecular-weight polyarylates with number-average molecular weight and polydispersity index in the range of 30,100–35,300 and 1.82–2.17, respectively, exhibited high gla… Show more
“…DSC curves of polyesters MAPES-1, MAPES-2 and MAPES-3 showed T g at 142°C, 166°C and 154°C, respectively. A comparison of data with literature T g values of polyesters from BPA-TPC, (210°C) 45 BPA-IPC (181°C) 51 and BPA-TPC+IPC (195°C) 51 indicated that there is a drop in T g of (co)polyesters by the incorporation of packing-disruptive pendant maleimide groups connected via alkylene spacer. Copolyesters showed T g values in the range 162°C-178°C and the values tend to decrease with increase in mol % incorporation of BPA-MA.Figure 4.DSC curves of (co)polyesters possessing pendant maleimide groups.…”
Section: Resultsmentioning
confidence: 87%
“…On the other hand, homopolyesters derived from BPA and IPC or BPA and TPC are not soluble in the above mentioned organic solvents at room temperature as reported in the literature. 44,45 The improved solubility characteristics of BPA-MA-based homopolyesters could be attributed to the presence of pendant groups which interrupt the chain packing and increase the free volume, thus, allowing the penetration of solvent into the polymer matrix. So also, the pendant maleimide groups connected via alkylene spacer provide additional handle for interactions with solvent molecules.…”
A new series of (co)polyesters possessing pendent maleimide groups was synthesized by low temperature solution polycondensation of 4, 4’-(5-maleimidopentane-2, 2-diyl) diphenol (BPA-MA) with isophthalic acid chloride (IPC), terephthalic acid chloride (TPC) and a mixture of TPC and IPC (50:50 mol %). Copolyesters were also synthesized by polycondensation of varying compositions of BPA-MA and bisphenol-A (BPA) with IPC. The chemical structures and compositions of (co)polyesters were confirmed by NMR spectroscopy. Inherent viscosity values and number-average molecular weights of (co)polyesters were in the range 0.50–0.76 dL/g and 17,700-32,100 g/mol, respectively, indicating the formation of reasonably high molecular weight polymers. (Co)polyesters were readily soluble in common organic solvents and could be cast into tough, transparent and flexible films from chloroform solutions. (Co)polyesters exhibited 10% weight loss and glass transition temperatures in the range 464–468 and 142–178°C, respectively. A representative copolyester possessing pendant maleimide groups was chemically modified via metal-free azide-maleimide 1,3-dipolar cycloaddition click reaction with two azido compounds, namely, (azidomethyl)benzene (Bz-N3) and 1-(azidomethyl)-pyrene (Py-N3) to yield corresponding modified copolyesters in a quantitative manner.
“…DSC curves of polyesters MAPES-1, MAPES-2 and MAPES-3 showed T g at 142°C, 166°C and 154°C, respectively. A comparison of data with literature T g values of polyesters from BPA-TPC, (210°C) 45 BPA-IPC (181°C) 51 and BPA-TPC+IPC (195°C) 51 indicated that there is a drop in T g of (co)polyesters by the incorporation of packing-disruptive pendant maleimide groups connected via alkylene spacer. Copolyesters showed T g values in the range 162°C-178°C and the values tend to decrease with increase in mol % incorporation of BPA-MA.Figure 4.DSC curves of (co)polyesters possessing pendant maleimide groups.…”
Section: Resultsmentioning
confidence: 87%
“…On the other hand, homopolyesters derived from BPA and IPC or BPA and TPC are not soluble in the above mentioned organic solvents at room temperature as reported in the literature. 44,45 The improved solubility characteristics of BPA-MA-based homopolyesters could be attributed to the presence of pendant groups which interrupt the chain packing and increase the free volume, thus, allowing the penetration of solvent into the polymer matrix. So also, the pendant maleimide groups connected via alkylene spacer provide additional handle for interactions with solvent molecules.…”
A new series of (co)polyesters possessing pendent maleimide groups was synthesized by low temperature solution polycondensation of 4, 4’-(5-maleimidopentane-2, 2-diyl) diphenol (BPA-MA) with isophthalic acid chloride (IPC), terephthalic acid chloride (TPC) and a mixture of TPC and IPC (50:50 mol %). Copolyesters were also synthesized by polycondensation of varying compositions of BPA-MA and bisphenol-A (BPA) with IPC. The chemical structures and compositions of (co)polyesters were confirmed by NMR spectroscopy. Inherent viscosity values and number-average molecular weights of (co)polyesters were in the range 0.50–0.76 dL/g and 17,700-32,100 g/mol, respectively, indicating the formation of reasonably high molecular weight polymers. (Co)polyesters were readily soluble in common organic solvents and could be cast into tough, transparent and flexible films from chloroform solutions. (Co)polyesters exhibited 10% weight loss and glass transition temperatures in the range 464–468 and 142–178°C, respectively. A representative copolyester possessing pendant maleimide groups was chemically modified via metal-free azide-maleimide 1,3-dipolar cycloaddition click reaction with two azido compounds, namely, (azidomethyl)benzene (Bz-N3) and 1-(azidomethyl)-pyrene (Py-N3) to yield corresponding modified copolyesters in a quantitative manner.
“…However, due to the regular chain structure, the high melting temperature of polyarylates leads to poor processing fluidity 10 . Therefore, researchers usually use molecular structure design methods to improve these deficiencies, which mainly include the introduction of flexible spacer groups, 11–13 bulky pendant groups, 14–17 heterocyclic or nonlinear units, 18,19 copolymerization 20,21 and so on.…”
A series of novel copolyarylates(co‐PARs) containing phenol red units in the backbone were synthesized by interfacial polymerization at 10°C from bisphenol A (BPA), phenol red (PR) and diacid chloride monomers. The obtained copolyarylates (co‐PARs) are all amorphous, the inherent viscosity (ηinh) of 0.22–0.62 dl g−1, and the number‐ and weight‐average molecular weight are 10,200–46,200 and 38,600–203,600, respectively. Adding a small number of PR units to the molecular chains improved the processing fluidity of polyarylates, and the glass transition temperatures (Tg) decreased from 202.8 to 166.7°C. In addition, the co‐PARs have excellent thermal stability with the maximum thermal decomposition temperature of 532.4–545.2°C. The co‐PARs show the best mechanical properties (57.6 MPa) when the PR content is 15 mol%. The transmittances of the co‐PARs at 400 and 450 nm are 79.2%–97.9% and 87.0%–99.8%, respectively, and the cut‐off wavelength is between 320 and 328 nm. The designed and synthesized copolyarylates can be considered as a promising and easy‐to‐process high‐performance engineering plastic.
A series of novel aromatic copolyesters derived from bisphenol B (BPB) and phenol red (PR) were synthesized by interfacial polymerization. The number‐ and weight‐average molecular weight (Mn and Mw) of the obtained amorphous aromatic copolyesters ranged from 1.06–1.80 × 104 to 2.01–6.17 × 104 g/mol, respectively. Density functional theory calculations showed that the reactivity of BPB was similar to that of bisphenol A. The reaction activation energy of BPB with terephthaloyl and isophthaloyl chloride (TPC and IPC) was 8.23 kcal/mol, and PR with IPC and TPC was 59.30 kcal/mol. Under the influence of the ethyl side group of BPB and the pendant group of PR, the solubility of the aromatic copolymer was improved, and the glass transition temperature (Tg) was 125.1–195.3°C, while Tmax could still be maintained above 525.72°C. The optical transmittance of the copolyesters at 450 nm (T450) was 69.29%–99.41%, and the tensile strength and Young's modulus were in the range of 46.79–58.59 MPa and 1.39–1.86 GPa respectively. All aromatic copolyesters exhibit good mechanical and processability properties and have great application potential as high‐performance plastics.
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