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     

Preparation and properties of polyamide-sulfonamides

A series of polyamide-sulfonamides was synthesized by the interfacial polycondensation of m- and p-chlorosulfonylbenzoyl chlorides with aliphatic and aromatic diamines at room temperature. Most of the polymers obtained were high molecular weight, film-forming materials. They were all amorphous and were soluble in a wide range of acidic and basic solvents. Both aliphatic and wholly aromatic polyamide-sulfonamides showed initial breakdown in the range of 320–360°C under thermogravimetric analysis in a nitrogen atmosphere.     

Organometallic polymers. XXV. Preparation of polyvinylferrocene

The synthetic details of solution polymerization in benzene and bulk polymerization of vinylferrocene are reported. In benzene solutions, with azobisisobutyronitrile (AIBN) as the initiator, small yields of low-polydispersity low molecular weight (M?_n ? 5000) polyvinylferrocene is obtained. However, high yields can be obtained by continuous or multiple AIBN addition. Higher molecular weight polymers and binodal polymers can be obtained as the monomer concentration is increased. In bulk polymerizations, yields of 80% can be obtained. The molecular weight increases as temperature decreases from 80 to 60°C in bulk polymerizations, and an increasing amount of insoluble polymer results. The soluble portion is often binodal, the higher molecular weight node consisting of an increasingly branched structure. Lower molecular weight polymer was readily fractionated into narrow fractions from benzene–methanol systems, but higher molecular weight polymer proved impossible to fractionate into narrow fractions due to branching.     

Regular Copolyamides. III. Preparation and Characterization of Regular Aliphatic/Aromatic Copolyoxamides

Regular aliphatic/aromatic copolyoxamides were prepared from diamine-oxamides and aromatic diacid chlorides by interfacial and solution polymerization. Solution polymerization in chloroform or dimethylacetamide is preferred for the preparation of large quantities of polymers but interfacial polymerization is most conveniently carried out for the preparation of polymers with high molecular weight. Aromatic diacid chlorides used included the diacid chlorides of terephthalic acid, isophthalic acid, 2,6-pyridinedicarboxylic acid, two isomeric naphthalene dicarboxylic acids, two cyclo-hexanedicarboxylic acid isomers, as well as 1,1-cyclobutane-dicarboxylic acid. Copolymers of diamine-oxamides with mixtures of acid chlorides of isophthalic and pyridine dicarboxylic acid and isophthalic acid/tetrachloroterephthalic acid have also been prepared. Most polymers are film-forming and are soluble in concentrated sulfuric acid, trifluoroacetic acid, and dimethylacetamide (containing several per cent LiCl). A number of these polymers gave dense or asymmetric membranes, particularly the polymers from ethylene diamine as the aliphatic diamine, particularly poly(iminoethyleneimino-oxalyliminoethyleneiminoisophthaloyl) (p-222I). Diamine oxamides with more than two amide groups in the molecules have been prepared, and in one case polymers with aromatic diacid chlorides have been prepared by interfacial polymerization. All regular aliphatic/aromatic copolyoxamides are high-melting and generally decompose above 350°C without melting. They can, however, be fabricated from solution into brittle fibers or into desalination membranes.     

Copolymers of 1,4-Dienes with Monoolefins via a Cyclocopolymerization Mechanism

The copolymerizations of divinyl ether, divinyl sulfone, and 1,4-pentadiene with certain monoolefinic monomers were studied. High molecular weight (inherent viscosity ≥ 1.0) copolymers of divinyl ether with maleic anhydride could be prepared using dichlorobenzoyl peroxide as the initiator. Derivatives of this copolymer were also prepared and studied. Divinyl sulfone and 1,4-pentadiene also gave soluble polymers with maleic anhydride but the inherent viscosities were much lower. Copolymerizations of these three dienes with dimethyl maleate, acrylonitrile, or vinyl acetate gave either low molecular weight materials at low conversions or cross-linked polymer at higher conversion. All of the soluble copolymers obtained showed little aliphatic unsaturation in the infrared, supporting the cyclocopolymerization theory.     

癸二酸-二苯并-18-冠-6共聚物的合成

脂肪族二元羧酸与二苯并 １８ 冠 ６在多聚磷酸中进行酰基化反应，可以制得酮型冠醚聚合物，二元酸的分子链长度会影响聚合反应的难易程度．对聚合反应条件进行优化控制，可以制得分子量高、成膜性能良好的癸二酸 二苯并 １８ 冠 ６共聚物．     

开环可控聚合制备脂肪族聚酯的最新研究进展

近年来,作为生物降解高分子材料,脂肪族聚酯由于良好的生物降解性及生物相容性受到人们的广泛关注。脂肪族聚酯在环境友好材料和生物医用材料领域都具有极大的应用价值,目前,部分聚酯材料已经商品化。与此同时,脂肪族聚酯的合成方法尤其是活性开环聚合也成为学术界及工业领域的研究热点。采用开环聚合法得到的聚合产物化学组成精确、分子量分...     

Halato-telechelic polymers. XV. Ionic cross-interactions of immiscible telechelic polymers: A reversible pathway to block copolymer-type materials

Phase separation of two immiscible polymer blends can be controlled by ionic cross-interactions of the end-groups as promoted by proton transfer from acid end-groups of polymer PA to aliphatic tert-amine end-groups of PB. IR spectroscopy supports the occurrence of proton transfer with formation of ammonium carboxylate ion pairs that influences the solution behavior of the blends. Optical microscopy illustrates the opportunity to get finely dispersed blends at a scale of ca. 0.2 μm depending on nature, molecular weight, and functionality of the immiscible polymers and strength of the ion pairs. T_g measurements are in agreement with the general pattern reported for multiphase block polymers, and give consistency to an analogy between finely phase separated blends of acid and tert-amine telechelic polymers and related block polymers.     

Preparation and properties of aromatic–aliphatic copolyamides from aromatic diisocyanates and dicarboxylic acids

Aromatic–aliphatic random copolyamides of high molecular weights were prepared by the high-temperature solution polycondensation from a combination of aromatic diisocyanates, 4,4′-methylenedi(phenyl isocyanate), and 2,4-tolylene diisocyanate, and a mixture of isophthalic acid and aliphatic dicarboxylic acids with 4–10 methylene groups. Reaction conditions, such as solvent, temperature, time, and catalyst were studied to determine the optimum conditions for the preparation of high molecular weight polymers. Glass transition temperatures of the copolyamides were in the range of 131–244°C and varied with combination and composition of the diisocyanates and dicarboxylic acids used. The copolyamides prepared from 2,4-tolylene diisocyanate had greater solubility and higher glass transition temperatures than those obtained from 4,4′-methylenedi(phenyl isocyanate).     

Copolymerization of Carbon Dioxide and Epoxide: Functionality of the Copolymer

Carbon dioxide and epoxide copolymerize in the presence of some organometallic catalyst systems under moderate conditions to give aliphatic polycarbonates of high molecular weight. Some metalloporphyrins of aluminum and zinc were found to act as novel catalysts for the polymerization of epoxide and for the copolymerization of carbon dioxide and epoxide, though not alternating. The polymers are characterized by the narrow molecular weight distribution and the unusual stereoregularity. Starting from the copolymerization of carbon dioxide and trimethylsilyl glycidyl ether with diethylzinc-water catalyst system, a readily degradable polycarbonate having hydroxyl group was obtained.     

Extended-chain polyamides: Polyoxamides and polyfumaramides

The synthesis of polyamides from short-chain aliphatic diacids, such as oxalic and fumaric acids, is difficult because of the thermal instability and volatility of the intermediates and side reactions with the polymerization media. A variety of synthetic routes to these polymers has been explored. Several aromatic polyoxamides with high molecular weight were obtained in high yield by an acid chloride vapor-solvent-water interfacial process. Polyoxamides of intermediate molecular weight also were obtained by preparation of oligomers from diamines and oxalic diesters and condensing these oligomers further in a thermal polymerization step. Aromatic polyfumaramides and terephthalamidefumaramides were prepared by modified solution procedures in amide solvents. Another route to polyfumaramides was the synthesis of N,N′-bis(4-aminophenyl) fumaramide and its use as a diamine with diacid chloride. The 1,4-phenylene and benzidine polyfumaramides and oxamides have extended-chain structures in solution in sulfuric, chlorosulfonic, and fluorosulfonic acids. Some of the polymers were soluble enough to yield liquid crystalline solutions. High-tenacity high-modulus fibers from poly(1,4-phenylene fumaramide/terephthalamide)s are described.     

The preparation of hyperbranched aromatic and aliphatic polyether epoxies by chloride‐catalyzed proton transfer polymerization from ABn and A2 + B3 monomers

Hyperbranched polymers consisting of aromatic or aliphatic polyether cores and epoxide chain‐end peripheries were prepared by proton transfer polymerization. AB₂ diepoxyphenol monomer 1 proved to be well suited for the preparation of hyperbranched aromatic polymer 2 by this proton transfer polymerization. The use of chloride‐ion catalysis, rather than conventional base catalysis, for the preparation of polymers from diepoxyphenol 1 offered a unique method to control the ultimate molecular weight of the polymer product through variations of the initial concentration of monomer 1 in tetrahydrofuran. An alternative route to hyperbranched polyether epoxies made use of commercially available or easily prepared aliphatic monomers of the types AB₂, AB₃, and A₂ + B₃. Although these aliphatic polymerizations can be initiated with a base, chloride‐ion catalysis proved most effective for controlling the polymerization. The hyperbranched epoxies were characterized by NMR spectroscopy, gel permeation chromatography, and multi‐angle laser light scattering. Chemical modification of the polymers after polymerization was carried out via nucleophilic addition on the epoxide groups or derivatization of the hydroxy substituents within the hyperbranched polymer structure. Spectroscopic measurements suggested that some such ring‐opened materials may adopt reverse unimolecular micellar structures in appropriate solution environments. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 4850–4869, 2000     

Synthesis and characterization of biodegradable poly(ϵ‐caprolactone urethane)s. I. Effect of the polyol molecular weight,catalyst, and chain extender on the molecular and physical characteristics

Biodegradable polyurethanes with potential for applications in medical implants were synthesized in bulk with aliphatic hexamethylene diisocyanate, isophorone diisocyanate, poly(?‐caprolactone) diols of various molecular weights, 1,4‐butane diol, 2‐amino‐1‐butanol, thiodiethylene diol, and 2‐mercaptoethyl ether chain extenders. The catalysts used were stannous octoate, dibutyltin dilaurate, ferric acetyl acetonate, magnesium methoxide, zinc octoate, and manganese 2‐ethyl hexanoate. The synthesis reactions were second‐order. All the materials had narrow, unimodal molecular weight distributions and polydispersity indices of 1.5–1.9. The chemical structures of the polyurethanes, as assessed from ¹H NMR and ¹³C NMR spectra, were in good agreement with the monomer stoichiometric ratios. The glass‐transition temperatures of the materials ranged from ?38 to ?57 °C and were higher for polymers based on isophorone diisocyanate and with higher hard‐segment contents. For polyurethanes with the same hard‐segment content, there was no effect of the material molecular weight on the thermal properties. The tensile strengths of the materials were 12–63 MPa, and the tensile moduli were 8–107 MPa. These increased with an increasing hard‐segment content. The least effective catalyst was magnesium methoxide, and the most effective was ferric acetyl acetonate. Stannous octoate and manganese 2‐ethyl hexanoate were less effective than dibutyltin dilaurate and zinc octoate. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 156–170, 2002     

Poly(diphenylsiloxy)arylazines. I. Synthesis and characterization

The synthesis of poly(diphenylsiloxy)arylazines and the preparation of the necessary aromatic aldehyde and azine precursors are described. This new family of polymers was prepared by a modified melt-condensation reaction of hydroxyl-substituted phenyl-and naphthylazines with bis(anilino)diphenylsilane. The resulting polymers have been characterized by elemental analysis, gel-permeation chromatography, vapor-phase osmometry, and absorption spectroscopy. Assignment of a polymer backbone composed of alternating diphenylsiloxane and arylazine moieties was made on the basis of the infrared absorption bands and by comparison of the fluorescence and absorption spectra of the polymers with those of model compounds. The molecular weight of the polymers was found to depend on temperature, reaction time, and the ratio of monomers. The formation of low molecular weight products was avoided by maintaining reaction temperatures below the decomposition point of the arylazine and by keeping the ratio of silylamine to arylazine at about 3:1. Molecular weights as high as 38,000 and extents of conversion of 85% were obtained by the described melt condensation procedure. The molecular weight of another member of the family was increased from 4600 to 8100 by a post-polymerization scheme, involving the reaction of aromatic hydroxyl and anilinosilane endgroups. Significant crosslinking via ortho hydroxyl groups during the polymerization of tetrahydroxyarylazines can be ruled out because of the solubility of the polymers in chloroform or tetrahydrofuran and on the basis of their fluorescence spectrum.     

Thermotropic homopolyesters. III. Preparation and properties of polymers based on 4′-hydroxyphenyl-4-hydroxycinnamate

Low-molecular-weight 4′-acetoxyphenyl-4-acetoxyoinnamate, as well as several polyesters synthesized from this monomer and aliphatic dibasic acids, exhibit thermotropic nematic phases. DSC heating curves for all of the polymers exhibit multiple transitions. The amount of crystallinity of these polymers at room temperature is small and the degree of order along the chain axis in the crystalline phase is poor. For the lower homologues the nematic phase exists over a broad temperature range of approximately 100°C. The polyester from chiral (+)-3-methyl adipate forms a thermotropic cholesteric phase. Both the diacetoxy monomer and azelate polymers of low molecular weight adopt the homeotropic texture on glass slides, but with increasing molecular weight the planar texture becomes preferred. Investigation of the effects of electric fields in the conduction regime upon the nematic phase of the diacetoxy monomer revealed that Williams domains are formed only with difficulty. In most cases, a stationary pattern appeared instead. At higher voltage the dynamic scattering mode (DSM) was obtained, and above this a field-induced transition to the isotropic phase. The azelate polyesters exhibited Williams domains and the DSM in the conduction regime. The formation time for Williams domains was fairly short for polymers having η_inh < 0.44 dL/g, but increased to 80 min when η_inh = 0.68 dL/g. The DSM was only observed for polymers having η_inh < 0.61 dL/g. For these polymers the critical frequency separating the conduction and dielectric regimes exhibits a stronger temperature dependence than that of low-molecular-weight nematogens. A new instability pattern is reported for the azelate polyesters in the dielectric regime.     

酚类聚合物在水相胶束中的酶促合成

本文报道辣根过氧化物酶在水相胶束中催化聚合取代酚类的研究。水相胶束中酶催化活力高，产物分子量均一；通过调节表面活笥剂和单体的浓度，可以有效地控制产物的分子量，从而建立了不同聚合度有机纳米材料酶促合成的新方法。产物具有较强的蓝紫色荧光及较好的耐热性能，是一种很有应用前景的蓝光材料。     

Dendritic resins for coating applications

Hyperbranched, aliphatic polyesters of theoretically calculated molar masses 1 200–44 300 (2–7 generations) were synthesized in the molten state from 2, 2-bis(hydroxymethyl)propionic acid (bis-MPA) (repeating unit of AB_x-type) and 2-ethyl-2-(hydroxymethyl)-1, 3-propanediol (TMP) (core molecule) using acid catalysis. The synthetic procedure was a pseudo-one-step divergent reaction. The degree of branching was found to be near 80 %. A study has also been made with respect to the rheological properties of the hyperbranched aliphatic polyesters. The polymers exhibit an almost newtonian behaviour in the molten state. They also exhibit a lower increase in viscosity with molecular weight than linear polymers. The surface functionality is shown to greatly affect the viscosity of the polymers.     

Improved molecular weight control in ring‐opening metathesis polymerization reactions in organic and aqueous media using N‐heterocyclic carbene–ruthenium arene/alkyne catalyst systems

A binary catalytic system, RuCl₂(N‐heterocyclic carbene)(p‐cymene)/alkyne, was developed for improved molecular weight control in ring‐opening metathesis polymerization (ROMP) reactions of norbornene derivatives in organic and aqueous media. Monometallic ruthenium arene compounds were activated using aryl and aliphatic terminal alkynes to form highly active metathesis species. The effects of alkyne structure and concentration on the overall catalytic activity were systematically investigated. The catalytic activity of the metathesis active species can be tuned by varying alkyne substituents. Also, the initiation rate of the ROMP reaction can be tuned by increasing the alkyne‐to‐Ru ratio. ROMP polymers with a wide range of molecular weights (91–832 kDa) were isolated in organic media, whereas polymers with a molecular weight range of 110–280 kDa with average particle sizes of 150–250 nm were isolated in aqueous media. Copyright © 2016 John Wiley & Sons, Ltd.     

New synthesis of liquid polysulfide polymers in the presence of hydrazine. I. Synthesis of linear polysulfide polymers from 1,1′-[methylenebis (oxy)]-bis-[2-chloroethane] and sodium tetrasulfide

The results of our studies show that liquid linear polysulfide polymers of an average molecular weight 4260–1030 g mol⁻¹ can be obtained by the reaction of sodium tetrasulfide and 1,1′-[methylenebis(oxy)]-bis-[2-chloroethane] in the presence of 2.0–5.0 mol of hydrazine and at least 4.0 mol of sodium hydroxide/mol of hydrazine in a one-step procedure. The disulfide polymers in the form of sodium mercaptide are soluble in the supernatant liquid from which they are separated by acidification of the solution to a pH value of about 4. The average molecular weight and the content of sulfur in the obtained linear polymers were determined and their IR spectra were recorded. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 1363–1367, 1997     

Reactions in the presence of organic phosphites,I: High temperature amidation in the absence of solvents

When reacted for periods of 5–10 min at temperatures of about 280–300°C in the presence of certain organic phosphites polymers that contain available carboxy and aliphatic amine groups undergo amidation. This reaction can increase the molecular weight of many aliphatic polyamides by their self-reaction in an extruder. Block or graft copolymers can be formed by reacting polymers that contain aliphatic amines with others that contain carboxyl. Studies of model compounds in the companion article (II) indicate that polymerization proceeds through an diaryloxy or dialkoxy amino phosphine intermediate to produce amide bonds and disubstituted phosphite reaction by-products. In the absence of primary amines in the reaction mixture an ester is slowly formed from the carboxyl end group of the polymer and the oxysubstituent of the phosphite. In no case was a phosphorus-containing mixed anhydride detected. The mechanistic identity of the low temperature reactions in article II and the high temperature reactions in this article has not been proved conclusively, however.