聚酰胺46的合成与结构研究：1.合成条件对产物分子量的影响

合成了高性能工程塑料聚酰胺４６并进行了基本表征，讨论了界面缩聚和溶液－固相缩聚时，有机相溶剂类型，单体浓度比，固相缩聚温度、真空度、反应时间对产物分子量的影响。     

Synthesis of High Molecular Weight Polyesters via In Vacuo Dehydrogenation Polymerization of Diols

The Milstein catalyst has proven to be highly effective for the conversion of alcohols to esters, as well as alcohols and amines to amides and polyamides. We have recently found that the catalyst's range can be extended to very efficient in vacuo dehydrogenation polymerization of α,ω‐diols to generate polyesters. The gaseous hydrogen byproduct that is produced is easily removed to drive the equilibrium toward product, which leads to the formation of high molecular weight polymer ( up to 145 000 g mol⁻¹). This optimized methodology works well to polymerize diols with a spacer of six carbons or more. Diols with fewer carbons are cyclized to lactone; the dividing point is the dehydrogenation of 1,5‐pentanediol, which leads to a mixture of polyester and lactone. Reported herein is the synthesis and characterization of five aliphatic polyesters prepared via this novel dehydrogenation polymerization approach.     

球形阳离子凝胶的制备及吸附性能研究

以醛、酮、胺为原料,采用溶液缩聚和反相悬浮聚合制备了新型高吸附容量球形阳离子凝胶,对产物的分子结构和表面形貌进行了表征。通过吸附实验,研究了其对阴离子染料氨基黑10B和表面活性剂十二烷基苯磺酸钠(SDBS)的吸附效果,并讨论了吸附行为和机理。实验结果表明,球形阳离子凝胶具有较高的阳离子度和大量极性官能团,其对氨基黑和SDBS的吸附是基于静电引力和氢键等分子间力共同作用的结果,凝胶吸附效果随溶液pH的降低而升高。吸附质分子随溶液渗透进入球形凝胶并被吸附于凝胶内表面,故该吸附主要由吸附质在凝胶内部的扩散过程控制,具有较高的饱和吸附量。     

Preparation of polyamides derived from 1,6-diamantane dicarboxylic chloride by solution polycondensation and interfacial polycondensation

1,6-Diamantane dicarboxvlic acyl chloride ( I ) was used as a monomer with various aromatic diamines to synthesize polyamides by interfacial polycondensation and solution polycon-densation. The polyamides prepared by interfacial polycondensation had inherent viscosities between 0.38 and 0.15 dL/g. The polyamides prepared by solution polycondensation had inherent viscosities between 0.62 and 0.25 dL/g. The polyamides IIIa prepared by solution polycondensation showed the main melting transition at 380°C by dynamic mechanical analysis. In addition, it was quite temperature-stable and maintained good mechanical properties (G′?10⁸ Pa) up to high temperatures close to the main transition well above 350°C. The polyamide IIIA had a tensile strength of 35 MPa, elongations to break of 10%, and initial modulus of 0.8 GPa. Some of the polyamides were soluble in NMP, DMAc, and DMSO, depending on soft segment moiety of diamine ( II ). The polyamides prepared by interfacial polycondensation have a greater tendency to form crystal than those prepared by solution polycondensation, as evidenced by x-ray diffraction studies. These polyamides had glass transition temperatures in the 270–300°C range, and 5% weight loss temperatures up to 435°C in nitrogen. © 1995 John Wiley & Sons, Inc.     

Synthesis of porphyrin‐embedded dendronized polymers by Suzuki polycondensation

Porphyrin‐embedded high molecular weight dendronized polymers up to fourth generation have been synthesized by Suzuki polycondensation of Fréchet‐type dendritic dibromo macromonomers and porphyrin diboronic pinacol ester. Higher generation lateral dendritic wedges not only endow the dendronized polymers with good solubility in commonly used organic solvents, but also prevent planar porphyrins and conjugated polymer backbones from aggregating by their “site isolation” effect. This type of porphyrin‐embedded dendronized polymers can be used as saturated red light‐emitting materials. With the increase of the generation of the lateral dendrons, the quantum yields of the dendronized polymers also gradually increased. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4030–4037, 2008     

Ways of selective polycondensation of L‐lysine towards linear α‐ and ε‐poly‐L‐lysine

Polylysines (PL) are highly interesting polymers due to their biocompatibility and their high number of reactive amino groups. So far it was not possible to synthesize them directly from L ‐lysine. Here, we describe two different synthesis routes to selectively polymerize lysine in one batch without the use of protection groups. Applying 1‐ethyl‐3‐(3‐dimethylaminopropyl) carbodiimide as activating agent for the polycondensation of L ‐lysine in water gave selectively linear ε‐PLL. In contrast to this, the polymerization of L ‐lysine in chloroform in the presence of dicyclohexyl carbodiimide and 18‐crown‐6 ether selectively afforded pure α‐PLL. We also assessed the capability of polylysine derivatization by polymer analog reactions with acetic anhydride, methyl iodide and 2,4,6‐trinitrobenzenesulfonic acid. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5053–5063, 2008     

Synthesis and characterization of radiopaque poly(ether urethane) with iodine‐Containing diol as chain extender

Novel radiopaque iodinated poly(ether urethane) (IPEU) was prepared by using iodine‐containing diol as chain extender in a normal two‐step condensation polymerization process. This new iodine‐containing diol was synthesized by iodination of terephthalic acid and then reaction with 3‐aminopropanol. The chemical structure of the diol chain extender and IPEU was characterized, and the basic properties of IPEU were measured and compared with PEU. X‐ray images showed that 15 wt % iodine‐containing IPEUs were highly radiopaque, and radiopacity did not decrease after 6‐week oxidative degradation treatment. Experimental results showed that IPEUs possessed good thermal stability, favorable mechanical properties, and noncytotoxicity. These results reveal that it is an effective route for the synthesis of biological polyurethane with radiopacity by using iodine‐containing diol as chain extender. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Efficient and rapid synthesis of polyureas and polythioureas from the reaction of urea and thiourea with diamines under microwave irradiation

Polyureas and polythioureas were readily synthesized by the reaction of aromatic and aliphatic amines with urea and thioureas, respectively, in good to excellent yields under microwave irradiation. The effects of the microwave irradiation time and power, the nature of the solvent, and the solid content of the monomers on the inherent viscosity of the polymers were investigated. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2106–2111, 2004     

Highly organosoluble and flexible polyimides with color lightness and transparency based on 2,2‐bis[4‐(2‐trifluoromethyl‐4‐aminophenoxy)‐3,5‐dimethylphenyl]propane

A new diamine containing isopropylidene, methyl substituted arylene ether, and trifluoromethyl groups, 2,2‐bis[4‐(2‐trifluoromethyl‐4‐aminophenoxy)‐3,5‐dimethylphenyl]propane (BTADP), was synthesized and used in preparation of a series of polyimides by direct polycondensation with various aromatic tetracarboxylic dianhydrides in N, N‐dimethylacetamide (DMAc). All polymers derived from diamine (BTADP) with trifluoromethyl substituents were highly organosoluble in the solvents, like N‐methyl‐2‐pyrrolidinone (NMP), N,N‐dimethylacetamide, N,N‐dimethylformamide (DMF), pyridine, chloroform, tetrahydrofuran (THF), dimethyl sulfoxide (DMSO), dichloromethane, cyclohexanone, and γ‐butyrolactone at room temperature or upon heating at 70 °C. Inherent viscosities of the polyimides were found to range between 0.58 and 0.97 dL·g^?1. These polyimides had glass transition temperatures between 256 and 307 °C, and their 10% mass loss temperatures ranged from 440 to 462 °C and 421 to 443 °C under nitrogen and air, respectively. These polyimides had low dielectric constants in the range of 2.84–3.09. All the polyimides could be cast into films from DMAc solutions and were thermally converted into color lightness, optically transparent, flexible, and tough polyimides. The polyimide films had a tensile strength in the range of 83–97 MPa and a tensile modulus in the range of 2.0–2.2 GPa. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5766–5774, 2004     

Effect of N‐methyl amide linkage on hydrogen bonding behavior and water transport properties of partially N‐methylated random aromatic copolyamides

The synthesis, conformational preferences, hydrogen bonding behaviors, and membrane properties of new partially N‐methylated random aromatic copolyamides were reported. These copolyamides were prepared by the low temperature polycondensations of isophthaloyl chloride with 3,5‐diaminobenzoic acid, N,N'‐dimethyl‐4,4'‐diaminodiphenyl ether (MDAE), and 4,4'‐diaminodiphenyl ether. The incorporation of the N‐methyl amide linkages into the polymer backbone decreased the contents of the cis conformation in the N‐methyl amide linkages and suppressed the hydrogen bondings among the amide linkages. Furthermore, the surface hydrophilicity of the copolyamides evaluated by water contact angle measurements decreased with increasing the MDAE unit in the polymer backbone. These experimental results indicated that the suppression of the hydrogen bonding and the existence of the tertiary amide linkage in the cis conformation induced the loose packing of the polymer chains. As a result, the incorporation of the N‐methyl amide linkage increased water flux and decreased salt rejection. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 3453–3462     

Acyl chloride‐facilitated condensation polymerization for the synthesis of heat‐sensitive poly(anhydride‐ester)s

We succeeded in developing the acyl chloride‐facilitated condensation polymerization method for the synthesis of new poly(anhydride‐ester)s with aromatic side groups, which cannot be polymerized by the classic melt condensation polymerization method. Using chlorinated and acylated carboxylic acids as the intermediates, the polymerization was carried out at low temperatures of 120 or 135 °C to yield pure poly(anhydride‐ester)s of molecular weights as high as 1.55 × 10⁵ with minimal side‐reactions. A homogeneous route of preparation was developed and optimized, using butyric anhydride as the acylating reagent and oxalyl chloride as the chlorinating reagent. A comparison of the mechanisms of the classic method and the new method indicates that the effects of transacylation—cyclization and oligomer formation—were greatly reduced due to the high reactivity of carboxylic acid chloride and the steric effect of bulky acyl groups. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5899–5915, 2007     

Chain-growth polycondensation for well-defined condensation polymers and polymer architecture

The historical development of our research on polycondensation that proceeds in a chain-growth polymerization manner ("chain-growth polycondensation") for well-defined condensation polymers is described. We first studied polycondensation in which change of the substituent effect induced by bond formation drove the reactivity of the polymer end group higher than that of the monomer. In this approach, well-defined aromatic polyamides, polyesters, polyethers, and poly(ether sulfone)s were obtained. The second approach was the study of the phase-transfer polymerization of a solid monomer dispersed in an organic solvent. In this type of polymerization, the solid monomer was physically unable to react with another monomer and was carried with the phase transfer catalyst into the solution phase where it reacted with an initiator and the polymer end group in the solvent in a chain polymerization manner. We also found catalyst-transfer polycondensation as a third approach to chain-growth polycondensation. In the Ni-catalyzed polycondensation of 2-bromo-5-chloromagnesiothiophenes, the Ni catalyst transferred to the polymer end group, and a coupling reaction occurred there to yield a well-defined polythiophene. This chain-growth polycondensation was applied to the synthesis of condensation polymer architectures such as block copolymers, star polymers, graft copolymers, and so on.     

Thermotropic copolyesters prepared by solution polycondensation with TsCl/DMF/pyridine condensing agent

When mixtures of terephthalic acid (TPA) and 1,6-naphthalenedicarboxylic acid (NDC) or 4,4′-dicarboxydiphenylether (DCDPE), TPA, and isophthalic acid (IPA) were reacted in pyridine (Py) with Tosyl chloride (TsCl)/DMF/Py to activate the diacids, the reaction mixture was soluble in Py, despite each of the separately activated diacids being insoluble. The solubility of the activated diacids was examined at a variety of acid compositions and temperatures. It was expected that a competitive reaction among the diacids with an aromatic diol in solution might be different from those in the melt, resulting in a different distribution of the acids in the copolymers. The TPA/NDC-phenylhydroquinone and DCDPE/TPA/IPA-chlorohydroquinone copolymers were prepared in solution using TsCl/DMF/Py as the condensing agent and the transition temperatures of these liquid crystalline copolyesters were compared to those obtained by melt copolycondensation. A practical depression of the transition temperature by the solution polycondensation was observed. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3710–3714, 1999     

Polycondensation of trialkoxysilane monomers accelerated by neighboring group participation of urea moiety

(Phenylaminomethyl)trimethoxysilane (= α‐amino‐siloxane) was treated with various isocyanates to obtain a series of siloxanes having urea moieties (= α‐urea‐siloxanes). Their hydrolysis‐condensation reactions were monitored with ²⁹Si NMR, to reveal that they exhibited much higher reactivity than a urea‐siloxane derived from [3‐(phenylamino)propyl]trimethoxysilane (= γ‐amino‐siloxane). When compared with the derivation of the γ‐amino‐siloxane into the corresponding γ‐urea‐siloxane, those of the α‐amino‐siloxane into the corresponding α‐urea‐siloxanes were accompanied by much larger shifts of the ²⁹Si NMR signal toward a higher magnetic field. These results suggested that the location of the urea moiety in the α‐urea‐siloxanes was favorable to its intramolecular coordination to the silicon atom to exhibit its “neighboring group participation” that promoted transformation of the tetravalent silicon center into the pentavalent one, which is more electrophilic to make the siloxanes more susceptive to undergo the hydrolysis and condensation reactions. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6654–6659, 2008     

Synthesis and chemical structural analysis of nitroxyl‐radical‐incorporated poly(acrylic acid/lactide/ϵ‐caprolactone) copolymers

The goal of this research is to synthesize biodegradable polymers that would have nitroxyl radical biological functions. Linear aliphatic polyesters were chosen as the starting materials. The hydroxyl‐terminated polylactide/?‐caprolactones (PBLC‐OHs) were first synthesized by melt ring‐opening copolymerization in the presence of benzyl alcohol and stannous octoate. PBLC‐OHs were used as the precursor for the synthesis of double bond‐functionalized polylactide/?‐caprolactones (PBLC‐Mas) by reacting the hydroxyl end groups of PBLC‐OH with maleic anhydride in melt at 130 °C. Acrylic acid/lactide/?‐caprolactone graft copolymers (PBLCAs) were then successfully carried out by the radical copolymerization of acrylic acid and PBLC‐Ma initiated by azobisisobutyronitrile. Finally, nitroxyl radicals [4‐amino‐2,2,6,6‐tetramethylpiperidine‐1‐oxy (TAM)] were incorporated into the carboxylic acid sites of the acrylic acid/lactide/?‐caprolactone copolymer (TAM‐PBLCA) by reacting TAM with PBLCA in the presence of N,N′‐carbonyl diimidazole. A high content of TAM was incorporated into the PBLCA copolymer. The polymers synthesized were characterized by ¹H and ¹³C NMR, Fourier transform infrared spectroscopy, and electron paramagnetic resonance spectra. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 4214–4226, 2001     

非晶聚对苯二甲酸乙二酯的制备与表征

采用引入U-polymer的路线制备了非晶聚对苯二甲酸乙二酯(APET).用DSC和DMA等手段研究了APET的性能.结果表明,经改性后得到的APET无结晶,透明性得到改善,玻璃化转变温度和储能模量都较PET有一定程度提高.     

Synthesis and characterization of postsulfonated poly(arylene ether sulfone) diblock copolymers for proton exchange membranes

Sulfonated poly(arylene ether sulfone) diblock copolymers were studied through the postsulfonation process. Two kinds of hydrophobic oligomers with a molecular weight of 20 kDa were prepared in advance as block sequences and then coupled together to obtain diblock copolymers. One oligomer was synthesized from bis(4‐hydroxyphenyl) sulfone (BHPS) and 4,4′‐difluorodiphenyl sulfone (DFDPS), which was thought to be incapable of postsulfonation. The other oligomer was synthesized from hydroquinone (HQ) and 4,4′‐dichlorodiphenyl sulfone (DCDPS), which successfully proceeded to a hydrophilic sequence as a result of sulfonation onto the HQ moiety after the coupling reaction. Consequently, a diblock copolymer with high molecular weight was obtained; although its intrinsic viscosity was too low to form a tough membrane because of its high rigidity and high crystallinity. Therefore, the use of decafluorobiphenyl (10F) as a termination reagent was investigated with the aim of achieving higher coupling reactivity and a kinky property. As a result, a sulfonated diblock copolymer was successfully obtained with sufficient molecular weight and intrinsic viscosity to form the membrane, as well as with adequate thermal properties. It was observed that proton conductivity, water uptake, and the water diffusion coefficient increased with higher ion exchange capacity. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 700–712, 2009     

Synthesis and characterization of isoindigo‐based polymers using CH‐arylation polycondensation reactions for organic photovoltaics

A series of three new low bandgap donor–acceptor–donor–acceptor^/ (D–A–D–A^/) polymers have been successfully synthesized based on the combination of isoindigo as the electron‐deficient acceptor and 3,4‐ethylenedioxythiophene as the electron‐rich donor, followed by CH‐arylation with different acceptors (4,7‐dibromo[c][1,2,5]‐(oxa, thia, and/or selena)diazole ( 4a‐c )). These polymers were used as donor materials for photovoltaic applications. All of the polymers are highly stable and show good solubility in chlorinated solvents. The highest power conversion efficiency of 1.6% was achieved in the bulk heterojunction photovoltaic device that consisted of poly ((E)?6‐(7‐(benzo‐[c][1,2,5]‐thiadiazol‐4‐yl)?2,3‐dihydrothieno‐[3,4‐b][1,4]dioxin‐5‐yl)?6′‐(2,3‐dihydrothieno‐[3,4‐b][1,4]‐dioxin‐5‐yl)?1,1′‐bis‐(2‐octyldodecyl)‐[3,3′‐biindolinylidene]‐2,2′‐dione) as the donor and PC₆₁BM as the acceptor, with a short‐circuit current density (J_sc) of 8.10 mA/cm², an open circuit voltage (V_oc) of 0.56 V and a fill factor of 35%, which indicates that these polymers are promising donors for polymer solar cell applications. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2926–2933     

Modeling Polycondensation of Lactic Acid

Summary: A mathematical model for the polycondensation of lactic acid accounting for water removal by diffusion is developed. The corresponding kinetic parameters are estimated by performing experiments under different sets of reaction conditions in open system. The model results are compared with the experimental ones and, after validating the model, parametric simulations are further carried out to understand the effects of operating conditions such as reaction temperature, catalyst activity, and reaction pressure.