Biodegradable polymers based on renewable resources. IX. Synthesis and degradation behavior of polycarbonates based on 1,4:3,6‐dianhydrohexitols and tartaric acid derivatives with pendant functional groups

Novel polycarbonates, with pendant functional groups, based on 1,4:3,6‐dianhydrohexitols and L ‐tartaric acid derivatives were synthesized. Solution polycondensations of 1,4:3,6‐dianhydro‐bis‐O‐(p‐nitrophenoxycarbonyl)hexitols and 2,3‐di‐O‐methyl‐L ‐threitol or 2,3‐O‐isopropylidene‐L ‐threitol afforded polycarbonates having pendant methoxy or isopropylidene groups, respectively, with number average molecular weight (M_n) values up to 3.6₁ × 10⁴. Subsequent acid‐catalyzed deprotection of isopropylidene groups gave well‐defined polycarbonates having pendant hydroxyl groups regularly distributed along the polymer chain. Differential scanning calorimetry (DSC) demonstrated that all the polycarbonates were amorphous with glass transition temperatures ranging from 57 to 98 °C. Degradability of the polycarbonates was assessed by hydrolysis test in phosphate buffer solution at 37 °C and by biochemical oxygen demand (BOD) measurements in an activated sludge at 25 °C. In both tests, the polycarbonates with pendant hydroxyl groups were degraded much faster than the polycarbonates with pendant methoxy and isopropylidene groups. It is noteworthy that degradation of the polycarbonates with pendant hydroxyl groups was remarkably fast. They were completely degraded within only 150 min in a phosphate buffer solution and their BOD‐biodegradability reached nearly 70% in an activated sludge after 28 days. The degradation behavior of the polycarbonates is discussed in terms of their chemical and physical properties. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3909–3919, 2005     

Biodegradable polymers based on renewable resources. II. Synthesis and biodegradability of polyesters containing furan rings

A series of polyesters were synthesized by the bulk polycondensations of the respective combinations of two difuranic diesters, i.e., bis(5-(methoxycarbonyl)-2-furyl)methane ( 4a ) and 1,1-bis(5-(methoxycarbonyl)-2-furyl)ethane ( 4b ), with two 1,4 : 3,6-dianhydrohexitols [1,4 : 3,6-dianhydro-D -glucitol ( 1 ) and 1,4 : 3,6-dianhydro-D -mannitol ( 2 )], four aliphatic diols, and three oligo(ethylene glycol)s. The polycondensations were carried out at 220–230°C in the presence of titanium isopropoxide as a catalyst, giving polyesters having number average molecular weight up to 2.4 × 10⁴. These polyesters are soluble in a variety of solvents including chlorinated hydrocarbons, 1,4-dioxane, dimethyl sulfoxide, dimethylformamide, and sulfolane. Soil-burial tests along with enzymatic degradation experiments showed that these polyesters are potentially biodegradable. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 2729–2737, 1997     

Synthesis and degradabilities of polyesters from 1,4:3,6-dianhydrohexitols and aliphatic dicarboxylic acids

Six different polyesters ( 6a–6c and 7a–7c ) were prepared by the bulk polycondensations of the respective combinations of 1,4:3,6-dianhydro-D-glucitol ( 3 ) and 1,4:3,6-dianhydro-D-mannitol ( 4 ) with succinyl dichloride ( 5a ), glutaryl dichloride ( 5b ), and adipoyl dichloride ( 5c ) at 140–180°C. Polyesters having number average molecular weights up to 2.6 ×10⁴ were obtained in high yields. Only polyester 7a based on 4 and 5a was partially crystalline, whereas all the other polyesters were amorphous. Thin films of these polyesters except that of 7a were spontancously hydrolyzed in a neutral phosphate buffer solution at 50°C, whereas they were reluctant to be hydrolyzed at 27°C. The polyesters were more or less degraded at 27°C by treatment with an activated sludge or by prolonged burial in soil. © 1995 John Wiley & Sons, Inc.     

New biodegradable polymers from renewable sources: Polyester‐carbonates based on 1,3‐propylene‐co‐1,4‐cyclohexanedimethylene succinate

α,ω‐Dihydroxy‐terminated copolymeric oligomers of a 1,3‐propylene/1,4‐cyclohexanedimethylene succinate structure were obtained by the thermal polycondensation of 1,3‐propanediol/1,4‐cyclohexanedimethanol/succinic acid mixtures. They were subsequently chain‐extended via phosgene synthesis to high molecular weight aliphatic/alicyclic copolyester‐carbonates. These new polymers, besides having a biodegradable backbone, originate from two monomers, namely, 1,3‐propanediol and succinic acid, which can be obtained by renewable sources. Therefore, they have a potential as environmentally friendly materials. All synthesized materials were characterized in reference to their molecular structure by ¹H NMR and ¹³C NMR. Their molecular weights and molecular weight distributions were determined by size exclusion chromatography, and their main thermal properties were measured by DSC. Spectroscopic characterizations were in full agreement with the proposed structures. 1,4‐Cyclohexanedimethanol was used as a diol comonomer to improve the overall thermal properties of poly(1,3‐propylene succinate). The results of the characterization performed show that the initial expectations were only partially satisfied. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2508–2519, 2001     

A non‐phosgene process to homopolycarbonate and copolycarbonates of isosorbide using dimethyl carbonate: Synthesis,characterization, and properties

Poly(isosorbide carbonate) (PIC) was synthesized by melt polycondensation of dimethyl carbonate (DMC) and isosorbide using lithium acetylacetonate (LiAcac) as the catalyst. The reaction conditions were optimized to achieve PIC with relatively high number‐average molecular weight (M_n) of 28,800 g/mol and isosorbide conversion of 95.2%. A series of poly(aliphatic diol‐co‐isosorbide carbonate)s (PAICs) were also synthesized by melt polycondensation of DMC with isosorbide and equimolar amounts of aliphatic diols (1,4‐butanediol, 1,5‐pentanediol, 1,6‐hexanediol, and 1,4‐cyclohexane dimethanol) in the presence of LiAcac and the TiO₂/SiO₂‐based catalyst (TSP‐44). PAICs with M_n values ranging from 18,700 to 34,400 g/mol and polydispersities between 1.64 and 1.69 were obtained. The ¹³C NMR analysis revealed the random microstructure of PAICs. The differential scanning calorimetry results demonstrated that all the PAICs were amorphous with a unique T_g ranging from 46 to 88 °C. The dynamic analysis results showed that the incorporation of linear or cyclohexane structure changed the dynamic mechanical properties of PIC drastically. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013     

Synthesis and characterization of poly(2,5‐furan dicarboxylate)s based on a variety of diols

Novel polyesters from renewable resources based on 2,5‐dicarboxylic acid and several diols were synthesized and characterized using different polycondensation techniques. The aliphatic diols were sufficiently volatile to allow the use of polytransesterifications, which gave high‐molecular weight semicrystalline materials with good thermal stability. In particular, the polyester based on ethylene glycol displayed properties comparable with those of its aromatic counterpart, poly(ethylene terephthalate), namely, the most important industrial polyester. The use of isosorbide gave rise to amorphous polymers with very stiff chains and hence a high glass transition temperature and an enhanced thermal stability. The interfacial polycondensation between the acid dichloride and hydroquinone produced a semicrystalline material with features similar to those of entirely aromatic polyesters, characterized essentially by the absence of melting and poor solubility, both associated with their remarkable chain rigidity. The replacement of hydroquinone with the corresponding benzylic diol was sufficient to provide a more tractable polyester. This study provided ample evidence in favor of the exploitation of furan monomers as renewable alternatives to fossil‐based aromatic homologs. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Novel Biodegradable Copolymers with a Periodic Sequence Structure Derived from Succinate Butan‐1,4‐diol,and Butan‐1,4‐diamine

Summary: Novel biodegradable copolymers derived from succinate, butan‐1,4‐diol, and butan‐1,4‐diamine were synthesized by two‐step polycondensation reactions. The obtained copolymers had a periodical‐sequence structure consisting of ester and amide units, and the melting temperatures of the periodic copolymers increased with an increase in amide content. The crystalline structure of the periodic copolymers differs from that of butylene succinate homopolymer (PBS), and these results suggest that the periodically introduced amide units are included in the crystalline phase forming a novel crystalline structure.

Periodic copolyester‐amides derived from succinate, butane‐1,4‐diol, and butan‐1,4‐diamine     

Copolymerization of carbon dioxide and propylene oxide with Ln(CCl3COO)3‐based catalyst: The role of rare‐earth compound in the catalytic system

A highly alternative copolymer of carbon dioxide and propylene oxide was obtained using a lanthanide trichloroacetates‐based ternary catalyst. The rare‐earth compound in the ternary catalyst was critical to dramatically raise the yield and molecular weight of the copolymer in addition to maintaining a high alternating ratio of the copolymer. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2751–2754, 2001     

A series of furan‐aromatic polyesters synthesized via direct esterification method based on renewable resources

A series of furan‐aromatic polyesters were successfully synthesized via direct esterification method starting from 2,5‐furandicarboxylic acid, ethylene glycol, 1,3‐propanediol, 1,4‐butanediol, 1,6‐hexanediol, and 1,8‐octanediol and characterized by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (¹H NMR), X‐ray diffraction (XRD), differential scanning calorimeter (DSC), thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), tensile tests, and so on. The preliminary evidence clearly showed that direct esterification method was rewarding and worthy to synthesize these furan‐aromatic polyesters. The densities of furan‐aromatic polyesters were ranging from 1.19 to 1.38 kg/m³. The FTIR and ¹H NMR confirmed their expected structures in detail. The results of XRD showed that these furan‐aromatic polyesters were crystalline polyesters. The results of DSC, TGA, DMA, and tensile tests showed that they behaved as thermoplastic polyester, had satisfactory thermal and mechanical properties, and their thermal stabilities were quite similar to that of corresponding benzene‐aromatic polyesters. The results of contact angle measurement showed that they were hydrophilic. The properties above showed that furan‐aromatic polyesters based on renewable resources could be a viable alternative to their successful petrochemical benzene‐aromatic counterpart. Furthermore, they could be used as biopolymer materials according their satisfactory thermal and mechanical properties and hydrophilicity in the future. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Novel organic–inorganic hybrid materials from renewable resources: Hydrosilylation of fatty acid derivatives

Novel hybrid organic–inorganic materials were prepared from 10‐undecenoyl triglyceride and methyl 3,4,5‐tris(10‐undecenoyloxy)benzoate via hydrosilylation. 1,4‐Bis(dimethylsilyl)benzene, tetrakis(dimethylsilyloxy)silane, and 2,4,6,8‐tetramethylcyclotetrasiloxane were used as crosslinkers. The hydrosilylation reaction was catalyzed by Karstedt's catalyst [Pt(0)–divinyltetramethyldisiloxane complex]. The networks were structurally characterized by Fourier transform infrared spectroscopy, ¹³C NMR, and ²⁹Si magic‐angle‐spinning NMR. The thermal properties of these hybrids were studied with differential scanning calorimetry, thermogravimetric analysis, and dynamic mechanical analysis. The obtained materials showed good transparency and promising properties for optical applications. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 6295–6307, 2005     

Advances in polymer precursors and bio‐based polymers synthesized from 5‐hydroxymethylfurfural

In recent years, considerable efforts have been made regarding the synthesis of renewable chemicals from natural resources. 5‐hydroxymethylfurfural (HMF) is an interesting platform chemical which has been widely exploited due to its rich chemistry and potential availability. The versatility of HMF has been demonstrated in several areas such as fine chemicals, biofuel precursors, and polymers. In particular, the potential to replace petroleum‐based analogues in the preparation of polymers associated with high performance has been observed owing to the structural rigidity of furan rings. This review aims at critically discuss the current research studies related to the derivatives of HMF, alongside with the synthesis and characterization of (co‐) polymers derived from HMF and its derivatives. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 1478–1492     

New polymers of carbonic acid. XXV. Photoreactive cholesteric polycarbonates derived from 2,5‐bis(4′‐hydroxybenzylidene)cyclopentanone and isosorbide

Several binary copolycarbonates were prepared by polycondensation of 2,5‐bis(4‐hydroxybenzylidene)cyclopentanone, BHBC, with methylhydroquinone, MHQ, hydroquinone 4‐hydroxybenzoate, HQHB, or isosorbide. Furthermore, five ternary copolycarbonates were prepared based on the aforementioned monomers. All polycondensations were conducted in pyridine with trichloromethyl chloroformate as condensing agent. All polycarbonates were characterized by elemental analyses, viscosity and DSC measurements, IR and ¹H‐ and ¹³C‐NMR spectroscopy, optical microscopy, and the WAXS powder pattern. All isosorbides containing binary and ternary copolycarbonates were found to form a cholesteric melt, but only three of them were capable to form a stable Grandjean texture upon shearing. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1125–1133, 1999     

Synthesis and characterization of novel renewable polyesters based on 2,5‐furandicarboxylic acid and 2,3‐butanediol

Novel polyesters from 2,5‐furandicarboxylic acid or 2,5‐dimethyl‐furandicarboxylate and 2,3‐butanediol have been synthesized via bulk polycondensation catalyzed by titanium (IV) n‐butoxide, tin (IV) ethylhexanoate, or zirconium (IV) butoxide. The polymers were analyzed by size exclusion chromatography, nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy (FTIR), matrix‐assisted laser ionization‐desorption time‐of‐flight mass spectrometry, electrospray ionization time‐of‐flight mass spectrometry, electrospray ionization quadruple time‐of‐flight mass spectroscopy, thermogravimetric analysis, and differential scanning calorimetry. Fully bio‐based polyesters with number average molecular weights ranging from 2 to 7 kg/mol were obtained which can be suitable for coating applications. The analysis of their thermal properties proved that these polyesters are thermally stable up to 270–300 °C, whereas their glass transition temperature (T_g) values were found between 70 and 110 °C. Furthermore, a material was prepared with a molecular weight of 13 kg/mol, with a T_g of 113 °C. This high T_g would make this material possibly suitable for hot‐fill applications. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013     

High‐efficiency blue light‐emitting polymers based on 3,6‐silafluorene and 2,7‐silafluorene

A novel blue‐emitting polymer based on 3,6‐silafluorene and 2,7‐silafluorene was synthesized via the Suzuki polycondensation. The resulting polymers are readily soluble in common organic solvents, such as toluene, xylene, THF, and chloroform. The thermal, electrochemical, photophysical, and electroluminescence properties of the resulting polymers were investigated. The device fabricated from the copolymer with a configuration of ITO/PEDOT:PSS/PVK/polymer/Ba/Al exhibited an external quantum efficiency of 1.95%, a luminous efficiency of 1.69 cd A^?1 and a maximal brightness of 6000 cd m^?2. It has been found that the incorporation of the 3,6‐silafluorene unit into the poly(2,7‐silafluorene) main chain can not only improve the color purity of the devices from the resulting copolymer but also enhance its device efficiency. Moreover, no undesired long‐wavelength green emission was observed in the PL spectra of P36‐27SiF90 compared to that of PFO with a dominating emission at 500–600 nm after thermal annealing at 200 °C for 8 h. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4941–4949, 2007     

A facile method to synthesize high‐molecular‐weight biobased polyesters from 2,5‐furandicarboxylic acid and long‐chain diols

In this study, biobased furan dicarboxylate polyesters have been prepared using 2,5‐furandicarboxylic acid (FDCA) and diols with high number of methylene groups (long‐chain diols), namely, 8, 9, 10, and 12. Because of the high boiling points of these diols, a modified procedure of the well‐known melt polycondensation was applied in this work. According to this, the dimethyl ester of FDCA (DMFD) reacted in the first transesterification stage with the corresponding diols forming bis‐hydroxy‐alkylene furan dicarboxylates (BHFD). In the second stage, the BHFD reacted with DMFD again at temperatures of 150–170 °C (for 4–5 h), and in the final stage, the temperature was raised to 210–230 °C (vacuum was applied for 2–3 h). The molecular weight of the polyesters and the content of oligomers, as was verified by gel permeation chromatography analysis, depend on the polycondensation time and temperature. The chemical structure of the polyesters was verified from ¹H NMR spectroscopy. All the polymers were found to be semicrystalline, with melting temperatures from 69 to 140 °C depending on the diol used. In addition, the mechanical properties also varied with the type of diol. The higher values were observed for poly(octylene 2,5‐furanoate), whereas the lowest values were observed for poly(dodecylene 2,5‐furanoate) with the higher number of methylene groups in its repeating unit. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 2617–2632     

Self‐assembling amphiphilic block copolymer from renewable δ‐decalactone and δ‐dodecalactone

Aliphatic polyesters have many applications in the biomedical field due to their properties and facile degradation. They are commonly synthesized via ring opening polymerization (ROP) with metal‐based catalysts, but as high temperatures are needed and the products contain metal, organocatalysts are now widely adopted to polymerize them at room temperature while also ensuring short reaction times. Here, 1,7,7‐triazabicyclo[4.4.0]‐dec‐5‐ene is used to polymerize less reactive but renewably‐derived lactones, namely δ‐decalactone and δ‐dodecalactone. These monomers were chosen in the attempt of creating renewable and highly lipophilic materials for drug delivery applications as alternatives to the more traditional, but non‐renewable δ‐valerolactone and ?‐caprolactone. A combination of ROP and living radical polymerization Reversible Addition‐Fragmentation Chain Transfer is proposed here to synthesize grafted block copolymers. They are able to self‐assemble in water, forming micelles where the lipophilic polyester core is able to entrap a lipophilic drug, thus making the system a good candidate for drug delivery. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55 , 3788–3797     

Biodegradable aliphatic thermoplastic polyurethane based on poly(ε‐caprolactone) and L‐lysine diisocyanate

A biodegradable aliphatic thermoplastic polyurethane based on L ‐lysine diisocyanate and 1,4‐butanediol hard block segments, and 2000 g/mol poly(ε‐caprolactone) diol soft block segments was synthesized. The resulting polymer was a tough thermoplastic with ultimate tensile strength of 33 MPa and elongation of 1000%. The polymer displayed classic segmented thermoplastic elastomer morphology with distinct hard block and soft block phases. Thermal and dynamic mechanical analyses determined that the material has a useful service temperature range of around ?40 °C to +40 °C, making it an excellent candidate for low‐temperature elastomer and film applications, and potentially as a material for use in temporary orthopedic implant devices. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2990–3000, 2006     

Novel synthesis of biodegradable linear and star block copolymers based on ε‐caprolactone and lactides using potassium‐based catalyst

Biodegradable, triblock poly(lactide)‐block‐poly(ε‐caprolactone)‐block‐poly(lactide) (PLA‐b‐PCL‐b‐PLA) copolymers and 3‐star‐(PCL‐b‐PLA) block copolymers were synthesized by ring opening polymerization of lactides in the presence of poly(ε‐caprolactone) diol or 3‐star‐poly(ε‐caprolactone) triol as macroinitiator and potassium hexamethyldisilazide as a catalyst. Polymerizations were carried out in toluene at room temperature to yield monomodal polymers of controlled molecular weight. The chemical structure of the copolymers was investigated by ¹H and ¹³C‐NMR. The formation of block copolymers was confirmed by NMR and DSC investigations. The effects of copolymer composition and molecular structure on the physical properties were investigated by GPC and DSC. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5363–5370, 2008     

Polyterephthalates made from Ethylene glycol, 1,4‐cyclohexanedimethanol,and isosorbide

Three series of terephthalate polyesters (copolyesters and terpolyesters) containing 70, 80, and 90 mol % of ethylene glycol respectively, 1,4‐cyclohexanedimethanol (CHDM) and isosorbide in varying ratios, were synthesized by melt polycondensation. It was found that only ～75 mol % of the feeding isosorbide was incorporated in the resulting polyesters and that their content in diethylene glycol oscillated between 2 and 4 mol %. The polyesters had weight‐average molecular weights in the 25,000–33,000 g mol^?1 range and polydispersities between 2 and 2.5. The combined ¹H and ¹³C NMR analysis revealed that the microstructure of all these polyesters was at random. They showed good thermal stability with decomposition temperatures above 400 °C. Their glass‐transition temperatures were observed to increase with the content in cyclic diols, this effect being more pronounced when isosorbide was the replacing comonomer. Only the series containing 90 mol % of ethylene terephthalate units was able to crystallize upon cooling from the melt. Compared isothermal crystallizations revealed that isosorbide was more effective than CHDM in repressing the crystallizability of PET. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Novel one‐ and two‐dimensional ZnII coordination polymers based on a versatile 3,6‐bis(pyridin‐4‐yl)phenanthrene‐9,10‐dione ligand

Two new Zn^II coordination polymers, namely, catena‐poly[[dibromidozinc(II)]‐μ‐[3,6‐bis(pyridin‐4‐yl)phenanthrene‐9,10‐dione‐κ²N:N′]], [ZnBr₂(C₂₄H₁₄N₂O₂)]_n, (1), and poly[[bromido[μ₃‐10‐hydroxy‐3,6‐bis(pyridin‐4‐yl)phenanthren‐9‐olato‐κ³N:N′:O⁹]zinc(II)] hemihydrate], {[ZnBr(C₂₄H₁₅N₂O₂)]·0.5H₂O}_n, (2), have been synthesized through hydrothermal reaction of ZnBr₂ and a 60° angular phenanthrenedione‐based linker, i.e. 3,6‐bis(pyridin‐4‐yl)phenanthrene‐9,10‐dione, in different solvent systems. Single‐crystal analysis reveals that polymer (1) features one‐dimensional zigzag chains connected by weak C—H...π and π–π interactions to form a two‐dimensional network. The two‐dimensional networks are further stacked in an ABAB fashion along the a axis through C—H...O hydrogen bonds. Layers A and B comprise left‐ and right‐handed helical chains, respectively. Coordination polymer (2) displays a wave‐like two‐dimensional layered structure with helical chains. In this compound, there are two opposite helical –Zn–HL– chains [HL is 10‐hydroxy‐3,6‐bis(pyridin‐4‐yl)phenanthren‐9‐olate] in adjacent layers. The layers are packed in an ABAB sequence and are further connected through O—H...Br and O—H...O hydrogen‐bond interactions to form a three‐dimensional framework. In (1) and (2), the mutidentate L and HL ligands exhibits different coordination modes.