SYNTHETIC STUDIES ON BLOOD COMPATIBLE BIOMATERIALS Ⅲ. SYNTHESIS, CHARAC-TERIZATION AND ANTITHROMBOGENICITY OF DIMETHYLDIPHEN YLPOLYSILOXANE/POLY (OXYTETRAM ETHYLENE)-POLYUREA SEGMENTED COPOLYMERS

A novel class of segmented copolymers, dimethyldiphenylpolysiloxane/poly (oxytetramethylene)-polyurea (PSPEU), was synthesized from α, ω-bis (γ-aminopropyl) dimethyldiphenylpolysiloxane (APMPS), which was prepared by means of basic ring-opening copolymerization of octamethylcyclotetrasiloxane, hexaphenylcyclotrisiloxane and 1, 3-bis (γ-aminopropyl) tetramethyl disiloxane. The relationships between the diphenylsiloxy contents and the properties of APMPS, including refractive index, glass transition temperature, solubility parameter as well as thermal stability, were investigated; meanwhile, the thermal stability, dynamic mechanical properties, mechanical properiesas well as the antithrombogenicity in vitro of the PSPEU were also revealed.     

SYNTHETI C STUDIES ON BLOOD COMPATIBLE BIOMATERIALS Ⅳ. SYNTHESIS, CHARACTERIZATION AND ANTITHROMBOGENICITY OF POLY-[N, N''''( p,p-OXYDIPHENYLENE)] PYROMELLI-TIMIDE-POLYDIMETHYLDIPHENYLSILOXANE SEGMENTED COPOLYMER

A novel class of aromatic polyimide-silicone segmented copolymer was synthesized with α, ω-bis (γ-aminopropyl) polydimethyldiphenylsiloxane (APMPS) as a silicone segment precursor, from which the segmented polyamic acid-b-silicone intermediate could be prepared simply with DMF as solvent. The segmented copolymer displays microphase separation and exhibits improved antithrombogenicity, which depends mainly upon both the content level and the DP of the silicone segment. Thermal stability and mechanical property of the copolymer are between that of the aromatic polyimide and the silicone, and also relate to both the content level and the DP of the silicone segment.     

SYNTHESIS AND CHARACTERIZATION OF NOVEL REACTIVE POLYORGANOSILOXANE CONTAINING NITRO GROUPS*

 A novel reactive polyorganosiloxane containing nitro groups was first prepared by acid-catalyzed equilibration polymerization. The monomer, 3-(4-nitrophenoxy)propylmethyldichlorosilane (NPPMS), was synthesized by hydrosilylation reaction with dicyclopentadienylplatinum(II) chloride (Cp₂PtC1₂) catalyst in high yield. The synthesized polynitroorganosiloxane, which has potential application as a precursor for synthesizing advanced functional polymers, was characterized by FTIR, ¹H-NMR, ¹³C-NMR, ²⁹Si-NMR, vapor pressure osmometry (VPO) and gel permeation chromatography (GPC).     

SYNTHESIS AND CHARACTERIZATION OF A NOVEL ALCOHOL-SOLUBLE POLYORGANOSILOXANE CONTAINING AMINO SIDE GROUPS*

 A novel alcohol-soluble polyorganosiloxane containing amino side groups, poly[3-(4-aminophenoxy)propylmethylsiloxane] (2), was first prepared by the reduction of nitro groups on 4-nitrophenoxypropyl side chains of poly[3-(4-nitrophenoxy)propylmethylsiloxane] (1). The reaction proceeded easily with nearly 100% conversion. The synthesized alcohol-soluble polymer 2, which has potential application as a precursor for preparing advanced functional polymers, was characterized by FTIR ¹H-NMR, ¹³C-NMR, ²⁹Si-NMR, VPO and GPC, respectively.     

SYNTHETIC STUDIES ON BLOOD COMPATIBLE BIOMATERIALSⅡ. SYNTHESIS OF POLY(ETHYLENEGLYCOL MONOMETHYLLTHER ) METHACRYLATE AND ANTITHROMBOGENICITY OF ITS COPOLYMERS

Poly (ethyleneglycol monomethylether) methacrylate (PEGMM)was synthesized by means of the reaction of methacrylyl chloride with sodium monomethylpolyethyleneglycoxide and was characterized by FTIR, ~1H-NMR,and ultraviolet spectrometries. A series of poly (vinyl alcohol)-graft-PEGMM (PVA-g-PEGMM )and methyl methacrylate-PEGMM copolymer (PMMA-PEGMM) were prepared and tested for antithrombogenicity in vitro. The results indicate that the antithrombogenicity of the copolymers basically increases with the increasing of the DP of polyoxyethylene (POE) chain and tends to a plateau after the DP around 114,i.e. the long chain structure of POE is favourable to the antithrombogenicityof its copolymers ;moreover, the extent of the improvement ofantithrombogenicity also relates to the PEGMM content of the copolymers and the kind of the matrix that the POE chains are located on. These results are consistent with the anticipation of the hypothesis of maintaining proteins normal conformations for blood compatible bioraaterials.     

GRAFTING OF SULFOBETAINE ONTO A POLYURETHANE SURFACE TO IMPROVE BLOOD COMPATIBILITY

On the molecular level, it is believed that polymers containing zwitterionic structures should be compatible withblood. In this work polyurethane films were grafted with sulfobetaine by a three-step procedure. In the first step, the films'surfaces were treated with hexamethylene diisocyanate (HDI) in toluene at 50℃ in the presence of di-n-butyl tin dilaurate(DBTDL) as a catalyst. The extent of the reaction was monitored by ATR-IR spectra; a maximum number of free NCOgroups was obtained after a reaction time of 90 min. In the second step, the hydroxyl groups of N,N-dimethylethylethanolamine (DMEA) were allowed to react in toluene with NCO groups bound on the surface. In the thirdstep, sulfobetaines were formed on the surface through the ring-opening reaction between tertiary amine of DMEA and 1,3-propanesultone (PS). The surfaces of the films were characterized by ATR-IR and XPS showing that the grafted surfaceswere composed of sulfobetaine. The results of the contact angle measurement show that the surface was strongly hydrophilic.The platelet adhesion test demonstrated that the films grafted with sulfobetaine have excellent blood compatibility.     

SYNTHESIS AND CHARACTERIZATION OF NOVEL BIPOLAR PPV-BASED COPOLYMER CONTAINING TRIAZOLE AND CARBAZOLE UNITS*

Two new blue light-emitting PPV-based conjugated copolymers containing both an electron-withdrawing unit(triazole-TAZ) and electron-rich moieties (carbazole-CAR and bicarbazole-BCAR were prepared by Wittig condensationpolymerization between the triazole diphosphonium salt and the corresponding dialdehyde monomers. Their structures andproperties were characterized by FT-IR, TGA, DSC, UV-Vis, PL spectroscopy and electrochemical measurements. Theresulting copolymers are soluble in common organic solvents and thermally stable with a T_g of 147℃ for TAZ-CAR-PPVand of 157℃ for TAZ-BCAR-PPV. The maximum photoluminescence wavelengths of TAZ-CAR-PPV and TAZ-BCAR-PPV film appear at 460 nm and 480 nm, respectively. Cyclic voltammetry measurement demonstrates that TAZ-BCAR-PPVhas good electrochemical reversibility, while TAZ-CAR-PPV exhibits the irreversible redox process. The triazole unit wasfound to be an effective π-conjugation interrupter and can play the rigid spacer role in determining the emission colour ofthe resulting copolymer.     

SYNTHESIS AND CHARACTERIZATION OF A NOVEL FLUORINE-CONTAINING HYDROPHOBICALLY ASSOCIATING POLYMER*

In this article, the synthesis and characterization of a novel fluoromonomer and its copolymer withacrylamide is reported. 2 -perfluoroamyl -4- hydroxylquinoline 2 was synthesized from ethyl 2, 2 -dihydro-perfluoroheptanoate in high yields. The monomer 4 was then synthesized from 2 in two steps readily in highyields. Synthesis and characterization of copolymers of acrylamide (AM) and the fluoromonomer wereinvestigated. The composition and intrinsic viscosity of these copolymers were studied. It was found that therheological properties of aqueous solutions of polyacrylamide were modified significantly when a smallproportion of the fluoromonomer 4 was incorporated on investigating the viscosity-concentration profiles,pseudoplasticity of these solutions and the effect of the presence of surfactant These results could beexplained by the hydrophobic association of the fluorocarbon segments in the aqueous solutions of thesecopolymers.     

SYNTHESIS AND CHARACTERIZATION OF A NOVEL REACTIVE LADDER-LIKE POLYSILSESQUIOXANE WITH LATERAL BROMOPHENYL GROUPS

A novel soluble, reactive ladder-like polysilsesquioxane (L) with lateral bromophenyl groups was synthesized successfully by stepwise coupling polymerization (SCP) method including preaminolysis, hydrolysis and polycondensation steps. The monomer 3-trichlorosilylpropoxy-4-bromobenzene (M) was first prepared via hydrosilylation reaction catalyzed by dicyclopentadienylplatinum (Ⅱ) dichloride (Cp2PtCl2). The title polymer (L) was characterized by ^1H-NMR, ^29Si-NMR,FTIR, X-ray diffraction (XRD), DSC and vapor pressure osmometry (VPO). The experimental results indicate that the polymer (L) possesses a typical ladder-like structure.     

SYNTHESIS AND CHARACTERIZATION OF A SOLUBLE LADDERLIKE POLYSILSESQUIOXANE CONTAINING REACTIVE ESTER GROUPS*

A novel soluble ladderlike polysilsesquioxane containing reactive ester groups (Ester-T) was synthesized for thefirst time by stepwise coupling polymerization including preammonolysis, controlled hydrolysis and polycondensation. Themonomer, 3-trichlorosilylpropoxy 4-acetoxybenzoate (M), was synthesized by hydrosilylation of allyloxy 4-acetoxybenzoatewith trichlorosilane in the presence of dicyclopentadienylplatinum (II) chloride (Cp_2PtCl_2) catalyst. Combination of FTIR,~1H-NMr, ~(13)C-NMR, ~(29)Si-NMR, XRD, DSC, TGA and VPO methods was used to demonstrate that the polymer obtained hasan ordered ladderlike structure. The synthesized Ester-T may have promising applications as a precursor of advanced functional polymers.     

SYNTHESIS AND CHARACTERIZATION OF A NOVEL BLUE LIGHT EMITTING ROD-COIL DIBLOCK OLIGOMER

Four new rod-coil diblock molecules, which had well-defined para-phenylene oligomers (PPP, from biphenyl toquinquephenyl) as rigid segments and poly(ethylene oxide) (PEO, M_w ca. 750) as flexible segments, were synhesized. Thechemical structure and the number of repeating unit in PEO coil and PPP rod were characterized by ~1H-NMR and MALDI-TOF mass spectromeny. The diblock oligomers showed good solubility in common organic solvents and aggregated in wateras characterized by a blue shift in UV-vis absorption spectra, a red shift in emission spectra, quenching of the fluorescenceand formation of the microfibrilla and fractal-like structures. The formation of different supramolecular structures meant thatthis effort might lead to commercial important highly organized functional materials.     

SYNTHESIS AND CHARACTERIZATION OF A NOVEL DOPANT (C3-ABSA) FOR SYNTHESIZING TUBULAR POLYANILINE*

 4-(3-(4-((4-Nitrophenyl)azo)phenyloxy)propyl)aminobenzene sulfonic acid (C3-ABSA) was synthesized by the reaction of 3-bromide-l-(4-((4-nitrophenyl)azo)phenyloxy)propane (B3) with sodium p-aminobenzene sulfonic acid (ABSA)and acidification with hydrochloric acid. The C3-ABSA was characterized by FTIR, ¹H-NMR and second ion mass spectrum (SIMS). The molecular formula of dehydrated C3-ABSA was estimated to be ca. C_{21H20O6N4S by SIMS. Its decomposition temperature was measured by TGA to be ca. 232℃. It was found that tubular polyaniline (PANI) with a conductivity of 1.1 S/cm at room temperature was successfully synthesized by in-situ doping polymerization in the presence of C3-ABSA as a dopant.}     

PREPARATION AND CHARACTERIZATION OF cis-,4-POLYBUTADIENE CONTAINING A FRACTION OF trans-1,4-POLYBUTADIENE

Polymerization of butadiene catalysed first with V(acac)_3-Al(i-Bu)_2Cl, then with Co(acac)_3-H_2O-Al(i-Bu)_2Cl has been studied. The polymer obtained was identified to be a new variety of cis-1,4-polybutadiene which contained a fraction of trans-1,4-polybutadiene chemically bonded to the cis-1,4-polybutadiene chains. Its molecular weight and trans-1,4 content can be regulated by varying the catalyst composition and concentration as well as other polymerization conditions. The trans-1,4 fraction, although it presents only in 9—16%, forms a crystalline phase in the matrix at room temperature and facilitates the crystallization of the polymer.     

A NEW OPTICALLY ACTIVE POLYURETHANE DERIVED FROM CHIRAL(2R, 3R)(+)-DIETHYL L-TARTRATE AND DIISOCYANATE*

Optically active polyurethane was synthesized by the polyaddition of (2R, 3R)-(+)-diethyl L-tartrate (DET), 4,4'-diphenylmethane diisocyanate (MDI) and polyethylene glycol (PEG) with variousmolecular weights at 60℃in DMSO. The polymers were characterized by specific rotation, DSC and ~1HNMR spectra.     

STUDY OF THE MOLECULAR MOTION AND COMPATIBILITY IN AB-CROSSLINKED POLYMER BASED ON POLYURETHANE AND POLYSTYRENE-co-ACRYLIC ACID BY SOLID STATE HIGH RESOLUTION NMR

The ~(13)C T_(1s) of --CH_3 side group in PPU/P (St-co-AA), AB-crosslinked polymers (i. e.ABCP) was studied by using high resolution solid state NMR. The rotation motion of --CH_3 sidegroup in PPU was analyzed by means of the average spectral density functions of internal rota-tion. The results showed that the rotation of the --CH_3 side group is related closely to the com-patibility between the two components. The compatibility was studied by analyzing the protonspin-lattice relaxation in rotating frame, spin-spin relaxation and spin-diffusion. The resultsshowed that the hydrogen bonds between the components play a major role in determining thecompatibility. Through spin diffusion studying, the soft phase domain size was calculated. Bystudying proton spin-spin relaxation, the content of each component in each phase and that ofeach phase in the samples can be obtained. The result shows that the content of interphase is related closely to the compatibility.     

EFFECT OF SEQUENCE STRUCTURE ON THE THERMOTROPIC LIQUID CRYSTALLINE PROPERTIES OF POLYESTERAMIDES BASED ON DIMETHYLBENZIDINE, BISPHENOL-A AND ρ-TEREPHTHALYL CHLORIDE*

A series of thermotropic liquid crystalline polyesteramides with differ-ent sequence structure based on dimethylbenzidine (DMBD), bisphenol-A(BPA) and p-terephthalyl chloride (TPC) was synthesized by changing the feeding order of monomers inlow temperature solution polycondensation system. By means of NMR and a computer pro-gram the sequence structure parameters were measured. The effect of sequence structureon liquid crystalline phase transition temperature of PEAs obtained was investigated.     

SYNTHESIS,CHARACTERIZATION AND OPTICAL PROPERTIES OF THE COPOLYMERS OF C_(60) AND 1-PHENYL-1-PROPYNE*

While WCl_6-Ph_4Sn fails to polymerize 1-phenyl-1-propyne (PP) at room temperature, highmolecular weight (M_w up to 410×10~3) polymers are obtained in high yields (up to 80%) when thepolymerizations of PP are carried out in the presence of C_(60) using the W catalyst under the same conditions.The polymers are soluble in common organic solvents such as THF, chloroform, and toluene. Molecularstructures of the polymers are characterized by FT-IR, UV, NMR, GPC and XRD, and it is found that C_(60) iscopolymerized with PP. Thus C_(60) plays the dual roles of comonomer and cocatalyst in the polymerizationreaction. C_(60) contents of the copolymers can be easily changed by varying the C_(60) amounts in the feedmixtures. The copolymers effectively limit strong 532 nm laser pulses, whose limiting performance issuperior to that of parent C_(60).     

(Li,Ca,A)2SiO4:Eu,Bi发光体的合成和发光性能的研究(A=Al,Y,La,Gd)

为了寻找新的发光基质材料,用高温固相反应合成了(Li,Ca,A)₂SiO₄:Eu,Bi系列发光体(A=Al,Y,La,Gd).通过激发光谱和发射光谱的测试.首次在碱土金属硅酸盐体系中研究了Al,Y,La,Gd等三价金属离子对Bi³⁺、Eu³⁺发光特性和Bi³⁺敏化Eu³⁺发光性能的影响,得到了良好的基质组成.实验结果表明.基质中适当含量的Gd³⁺可大幅度提高Eu³⁺的发光强度,使⁵D₀-⁷F₂发射强度增加6倍.Bi³⁺对Eu³⁺有很好的敏化作用,以A=Gd或Al时较好,对⁵D₀-⁷F₁辐射跃迁的敏化效果尤为突出.