X射线不透性体温固化聚氨酯髓核假体材料的研究

为了制备X光可显影且可以体温固化的聚氨酯,合成了N,N'-双(1,3-二羟基丙基)-2,3,5,6-四碘对苯二甲酰胺(BDTIP)含碘四元醇,将其作为聚氨酯固化的交联剂和X光显影剂,与聚氨酯预聚物混合反应得到一种新的可用于人工髓核假体的材料.利用红外光谱监测BDTIP的反应程度;利用X射线对不同BDTIP含量的聚氨酯材料的显影效果进行评定;利用噻唑蓝(MTT)比色法测试材料细胞毒性,并对具有不同碘含量聚氨酯材料的力学性能进行了对比研究.结果表明,碘的加入对聚氨酯的显影效果有很好的促进作用,较低碘含量(0.2 wt%)的聚氨酯材料即有较好的X光显影效果,而且此时聚氨酯依然保持较好的力学性能;MTT法测试表明含BDTIP的聚氨酯材料不具有细胞毒性.     

具有X-射线自显影功能的碘代聚氨酯栓塞剂材料的研究

设计合成四碘代双酚A(IBPA)作为扩链剂,以聚丁二酸丁二醇酯(PBS-OH)为软段、异佛尔酮二异氰酸酯(IPDI)和IBPA为硬段,通过偶联反应获得一种新型X-射线聚氨酯显影材料.红外光谱和核磁共振氢谱确定所合成碘代聚氨酯(I-PUs)的结构与组成,并用示差扫描量热法,热重分析,X-射线衍射仪和临床X-射线仪评价不同IBPA含量的碘代聚氨酯的热性能、结晶性和显影效果.结果表明,碘代扩链剂IBPA较高含量的引入对聚合物的热稳定性有一定的影响,并促使聚氨酯由结晶态向非晶态转变.引入IBPA对聚氨酯的显影效果有很好的促进增强作用,聚氨酯材料及微球均具有较好的X光显影效果.噻唑蓝比色法(MTT)评价细胞毒性证实制备的较高碘含量的聚氨酯材料均无细胞毒性,是一种很好的血管栓塞剂材料.     

芳香族偶氮苯封端的液晶聚氨酯膜的制备及其液晶性能

以苯胺或对硝基苯胺为主要原料,经重氮偶合反应制得液晶基元对氨基偶氮苯(LC1)或对硝基偶氮苯胺( LC2),再用聚氨酯预聚体[由聚乙二醇(PEG400,含-OH)和二苯基甲烷二异氰酸酯(MDI,含-NCO)制得,r=n(-OH)∶n(-NCO)]封端合成了一系列偶氮液晶聚氨酯膜LCPU'1和LCPU'2,其结构和液晶性能经UV,IR,TGA,POM与XRD表征.结果表明,LCPU'1和LCPU'2为具有良好热稳定性的热致型向列型液晶聚氨酯.LCPU3/41的接触角较大,耐水性相对较佳,硬度也相对适中.     

关于超高分子量聚丙烯超拉伸膜的结构性能的研究——Ⅱ.形态结构变化对力学性能的影响

 用X-射线衍射、动态力学测定等手段研究了不同拉伸倍数的超高分子量聚丙烯薄膜的力学性能的变化.以X-射线衍射法并基于串联力学模型的假设得到的各样品的表观晶区模量E_c^app约为34-38GPa.样品模量E_b随拉伸倍数增加而逐渐增大,其变化趋势与非晶区取向因子的变化相类似,说明非晶区取向是左右样品模量的重要因素.室温下,69倍拉伸样品的模量为27GPa,约为表观结晶模量的3/4,且其值在-150-160℃的温度范围内没有急剧变化,说明超拉伸明显改善了材料的力学性能及热稳定性.在各拉伸样品中,考虑伸直链结晶生成的可能性,利用并串联力学模型对伸直链结晶的体积分数做了估算,并对X-射线衍射法所得表观结晶模量进行了修正,认为室温下聚丙烯的真正晶区模量约为47GPa.     

聚氨酯/石墨烯纳米复合物的原位制备及温度-电阻行为

采用原位聚合法,利用蓖麻油基聚氨酯预聚体与还原石墨烯残留羟基或羧基反应,制得聚氨酯/石墨烯纳米复合物,并利用红外光谱和拉曼光谱对其分子结构进行了表征.此外,分别采用热重分析仪、X-射线衍射、扫描电子显微镜、ZC36型高阻计等表征手段对其热稳定性、形态结构以及电阻率-温度行为进行了分析.结果显示,石墨烯添加致使复合物的交联网络增加和物理交联增强.因而,聚氨酯/石墨烯复合物的室温电阻率有所升高和电阻率-温度行为增强.尤其是,当掺杂3%石墨烯时,聚氨酯复合物的正电阻率温度效应(PTC效应)提高近3个数量级.因此,聚氨酯基复合物应该是一种具有潜在应用价值的低掺杂PTC纳米复合物材料.     

赖氨酸乙酯扩链聚氨酯弹性体的制备

以1,6-六亚甲基二异氰酸酯(HDI)为硬段、聚碳酸酯二元醇(PCDL)为软段、赖氨酸乙酯盐酸盐(Lys-OEt)作为扩链剂合成一种新型聚碳酸酯型聚氨酯弹性体.通过力学性能测试、原子力显微镜(AFM)、红外光谱分析和细胞培养,探讨了聚氨酯弹性体软硬段比例、扩链剂对材料性能的影响和材料的细胞毒性.结果表明:随着硬段含量的增加,聚氨酯的机械性能提高.采用Lys-OEt扩链的聚氨酯弹性体拉伸强度达到18.6 MPa,在Lys-OEt、1,4-丁二醇(BDO)、二羟甲基丙酸(DMPA)3种扩链剂中力学性能最佳.初步的细胞培养实验证明,该材料具有良好的细胞相容性.     

热处理对溶致性液晶高分子PBT薄膜结构和性能的影响

聚苯撑苯并二噻唑(PBT)薄膜是由液晶相溶液在应力下制成的,主要用作结构材料或复合材料的增强剂。本文对不同条件下热处理的PBT膜进行了FTIR、广角X-射线衍射、元素分析和力学性能的测定研究,证明了热处理能进一步完成关环反应,使分子链结构更规整,凝聚态结构更有序,明显地提高材料的力学性能和热稳定性,并提出了最佳的热处理温度。     

关于超高分子量聚丙烯超拉伸膜的结构性能的研究——Ⅱ.形态结构变化对力学性能的影响

用X-射线衍射、动态力学测定等手段研究了不同拉伸倍数的超高分子量聚丙烯薄膜的力学性能的变化.以X-射线衍射法并基于串联力学模型的假设得到的各样品的表观晶区模量E_c~(app)约为34-38GPa.样品模量E_b随拉伸倍数增加而逐渐增大,其变化趋势与非晶区取向因子的变化相类似,说明非晶区取向是左右样品模量的重要因素.室温下,69倍拉伸样品的模量为27GPa,约为表观结晶模量的3/4,且其值在-150-160℃的温度范围内没有急剧变化,说明超拉伸明显改善了材料的力学性能及热稳定性.在各拉伸样品中,考虑伸直链结晶生成的可能性,利用并串联力学模型对伸直链结晶的体积分数做了估算,并对X-射线衍射法所得表观结晶模量进行了修正,认为室温下聚丙烯的真正晶区模量约为47GPa.     

双聚己内酯封端苯胺三聚体三嵌段聚合物的合成与研究

以双氨基封端的苯胺三聚体为引发剂,辛酸亚锡为催化剂,在无水甲苯溶液中引发ε-己内酯(ε-CL)开环聚合,得到了分子量约为5900的双聚己内酯封端苯胺三聚体ABA型三嵌段聚合物,并通过核磁、红外、紫外、循环伏安以及热分析等手段对聚合物进行了结构与性能的研究.所得的三嵌段聚合物在有机溶剂中具有较好的溶解性,相比于双氨封端的苯胺三聚体具有更好的热稳定性和电化学稳定性,特别地,所得聚合物对溶液pH值的变化响应范围更宽、更灵敏.     

丝素蛋白与聚氨酯共混膜的制备及结构和性能

采用溶液共混法制备了一系列不同组成的聚氨酯/丝素共混膜.利用红外光谱和广角X-射线衍射表征聚氨酯/丝素共混膜的结构;扫描电镜观察共混膜的断面;紫外-可见光谱测定共混膜的透光性;运用拉伸实验研究不同配比聚氨酯/丝素共混膜的力学性能.结果表明聚氨酯和丝素蛋白分子间存在较强的氢键相互作用.当丝素含量低于3 wt%时,试膜的断面较光滑,丝素蛋白分子进入聚氨酯网状结构中,破坏了聚氨酯分子内硬段和软段间的氢键作用.随着丝素含量进一步增大,丝素小颗粒均匀分散在聚氨酯基体中,二者之间具有较好的相容性.本实验所采用的制膜条件有利于促进丝素蛋白大分子的结晶.丝素蛋白对聚氨酯具有良好的增强效果,当丝素含量从0到5.6 wt%变化时,共混试片的断裂强度由0.56 MPa增大到4.60 MPa,杨氏模量由0.14 MPa增大到1.71 MPa,断裂伸长率从1065%下降到988%.丝素蛋白增强聚氨酯共混膜的强度显著增加,但弹性基本保持不变.     

Diaminobisbenzothiazole chain extended polyurethanes as a novel class of thermoplastic polyurethane elastomers with improved thermal stability and electrical insulation properties

This work was devoted to the development of a new class of modified polyurethane as an electrical insulating material. For this purpose, NCO‐terminated urethane prepolymers at different NCO contents were prepared and chain extended by 6,6′‐oxybis(2‐aminobenzothiazole) (ABT) to produce thermoplastic polyurethane elastomers. All of the polymers were characterized by FTIR and ¹HNMR spectroscopies and examined for their thermal, mechanical, and electrical properties. The dynamic mechanical measurements results showed two glass transitions indicating phase separation. A considerable improvement in the thermal and electrical properties in comparison to common polyurethanes was detected for these polymers. The level of enhancement in the measured properties was related to the polyol molecular weight, hard segment content, and consequently the amount of the introduced urea and benzothiazole moieties. These findings indicated the improved high service temperature performance of these materials as electrical insulator for metallic surfaces. Copyright © 2008 John Wiley & Sons, Ltd.     

Preparation and Characterization of Optically Active Polyurethane from Rotatory Binaphthol Monomer and Polyurethane Prepolymer

Optically active polymers are promising multifunctional materials with great application potentials. Herein, environmentally friendly optically active polyurethanes (OPUs) were obtained by introducing rotatory binaphthol monomer to polyurethane. The influence of binaphthol monomer content on the structure, mechanical properties, infrared emissivity, and thermal insulation of OPUs was studied intensively. Structure characterization indicated that the optically active polyurethanes have been successfully synthesized. The OPU synthesized with BIMOL and BDO at the mole ratio of 1:1 presented better thermal resistance. In addition, OPUs showed enhanced tensile strength and stretchability with the increase of BINOL content to a certain extent due to its rigid structural features and high molecular weight. The optically active polyurethanes showed lower infrared emissivity values (8–14 μm) than waterborne polyurethane (WPU), and the infrared emissivity decreased from 0.850 to 0.572 as the content of the BINOL monomer increased. Moreover, OPU4 exhibited the best heat insulation and cooling ability with about a 7 °C temperature difference. The thus-synthesized optically active polyurethanes provide an effective solution for developing highly effective thermal insulation materials.     

AB CROSSLINKED POLYURETHANES THROUGH IONIC CROSSLINKING: INFLUENCE OF CROSSLINKING NETWORKS ON PHYSICO CHEMICAL PROPERTIES

Isocyanate-terminated prepolymers were synthesized using poly(tetramethylene oxide)glycol of molecular weight 1000 (PTMG₁₀₀₀) with tolylene-2,4-diisocyanate (TDI). The prepolymers were chain extended with N-methyldiethanolamine (N-MDEA) to form polyurethanes containing tertiary nitrogen. These polyurethanes were crosslinked with bromine terminated polyurethane, poly(urethane-imide), and poly(urethane-siloxane) through the formation of cationomers at tertiary nitrogen sites across the backbone polyurethanes.

The crosslinked cationomeric polyurethanes were characterized by Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), mechanical analyses, (static and dynamic), and static contact angles measurements. FTIR spectral studies confirms the formation of bromine terminated poly(urethane-imide) and poly(urethane-siloxane), as well as quaternization of the tertiary nitrogen which leads to crosslinking. A comparison of thermal stabilities of crosslinked polymers with respect to the chemical nature of bromine terminated prepolymers (BTP) indicates improved thermal stability for poly(urethane-imide) based ABCP. Stress-strain analysis shows high elongation values for poly(urethane-siloxane) and poly(urethane-imide) based ABCPs. Dynamic mechanical analysis reveals better damping for poly(urethane- siloxane) based AB crosslinked polymers.     

环氧改性水性聚氨酯乳液的制备及其膜性能

以聚己内酯二元醇(CAPA)为软段,异佛尔酮二异氰酸酯(IPDI)和六亚甲基二异氰酸酯(HDI)为硬段,环氧树脂E-44为大分子交联剂,经相转化法合成了一系列环氧树脂改性负离子水性聚氨酯(EPPU)自乳化乳液,并制备了改性水性聚氨酯的固化膜.通过FTIR、TGA及接触角、力学性能测试对聚合物结构及其膜性能进行了研究.通过原子力显微镜(AFM)观察膜表面形态和表面粗糙度.乳液粒径及粒径分布通过动态激光光散射法(DLLS)测定.FTIR分析表明环氧树脂的羟基和环氧基都参与了发应.TGA表明,环氧树脂的加入可以提高聚氨酯的热稳定性.随着w(E-44)增大,改性聚氨酯膜的拉伸强度得到改善,断裂伸长率减小.随着w(E-44)增大,乳液粒径增大,薄膜的接触角增大,改性后的PU膜表面光滑度下降,拒水性增强.     

SURFACE STRUCTURE AND BULK PROPERTIES OF FLUORINATED POLY(ETHER URETHANE)S AND POLY(ETHER URETHANE) BLENDS

INTRODUCTIONPolyurethanes (PU) have been widely used for manufacturing medical devices because of their excellentmechanical properties and moderate biocompatibility[1]. Although polyurethanes used in applications requiringall of the above properties have been successful for short-term use, the problems of long-term thromboresistanceand biostability in a biological environment still remain unsolved[2,3]. A legitimate approach to improving theproperties of polyurethanes is introduction of f…     

Synthesis and characterization of semi-interpenetrating polymer networks using biocompatible polyurethane and acrylamide monomer

Semi-interpenetrating polymer networks (semi-IPNs) of acrylamide based polyurethanes were synthesized from different NCO-terminated polyurethane prepolymers derived from polytetramethylene ether glycol (PTMEG). The resulting semi-IPNs were characterized using FTIR, DSC, and TGA measurements. Variation in the NCO/OH ratio and the molecular weight of the diol gave semi-IPNs with different types of mechanical characteristics varying from elastomer to brittle plastic properties. Differential scanning calorimetry (DSC) data revealed a difference in the glass transition temperature (T_g) of the semi-IPNs relative to the normal polyacrylamide (PAAM) network. Incorporation of polyurethane into polyacrylamide network in the form of an interpenetrating polymer networks enhanced the mechanical and thermal properties of the semi-IPNs due to higher crosslink density imparted by the hard segment content. The swelling behavior of both the semi-IPNs and the individual polyacrylamide (PAAM) network in different pH conditions were investigated to check their biocompatibility and possible usage in biomedical field. The hydrolytic stability of the semi-IPNs and the polyacrylamide (PAMM) network was studied using phosphate buffer solution. The hydrolytic stability of the semi-IPNs was found to be more compared to PAMM network. The morphology of both the semi-IPNs and the individual polyacrylamide (PAAM) network was investigated using SEM.     

Investigation of thermal,mechanical, and electrical properties of novel polyurethanes/high molecular weight polybenzoxazine blends

In order to prepare tough polyurethane (PU) electrical insulator with improved thermal stability and electrical insulating properties, high molecular weight polybenzoxazine precursor was mixed and co‐cured with crosslinkable urethane prepolymers. Polybenzoxazine precursor (Bmda) was synthesized from reaction of bisphenol‐A, methylenedianiline, and paraformaldehyde. Epoxy‐terminated polyurethanes (EPU1‐4) were prepared by the reaction of glycidol with NCO‐terminated urethane oligomers. The oligomers were prepared from different molecular weight versions of polycaprolactone polyol (CAPA) and hexamethylene diisocyanate. Blends were prepared through thermal treatment of equal weights of two precursors dissolved in chloroform. Optimum curing condition was determined by DSC and DMTA analysis and measurement of the gel content for cured samples. Viscoelastic, thermal, mechanical, and electrical properties of cured samples were investigated and structure–property relationship was established. Copyright © 2008 John Wiley & Sons, Ltd.     

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