硬段类型和含量对嵌段聚氨酯脲性能的影响

以聚己二酸乙二醇-丙二醇酯二醇(PEPA)为软段,分别采用4种二胺扩链剂和3种二异氰酸酯为硬段,通过预聚体法合成了一系列不同硬段结构和含量的聚氨酯脲弹性体,并采用红外光谱、热失重分析、差示扫描量热和拉伸测试等手段,研究了硬段类型及含量对聚氨酯脲性能的影响。结果表明,在软段结构一致,硬段含量接近的情况下,兼具柔性和刚性的硬段有助于提升聚氨酯脲的力学性能、热学性能和微相分离程度。几种二胺扩链剂和二异氰酸酯中,由二苯基甲烷二异氰酸酯(MDI)和4,4'-二氨基二苯醚(ODA)构成的硬段性能最佳;在软、硬段结构一致的情况下,硬段含量对聚氨酯脲性能影响明显。随着硬段含量增加,聚氨酯脲的拉伸强度、微相分离程度先增大后减小,5%热失重温度和断裂伸长率逐渐下降。当PEPA/MDI/ODA摩尔比为1∶0.5∶0.5(硬段含量31.7%),聚氨酯脲拉伸强度达51.5 MPa,断裂伸长率为709%,5%热失重温度为282.7℃,性能最佳。     

硬段含量对阴/非离子型水性聚氨酯性能影响的研究

以二羟甲基丁酸(DMBA)、聚乙二醇(PEG)为亲水单体,聚氧化丙烯二醇(PPG)为多元醇组分、甲苯二异氰酸酯(TDI)为异氰酸酯组分,采用预聚体法合成了一系列阴/非离子型水性聚氨酯(WPU)。通过万能材料试验机、傅里叶变换红外光谱仪、粒径测试、表面张力测试等分析表征手段研究了硬段含量对阴/非离子型WPU乳液及胶膜性能的影响。结果表明:随着硬段含量的提高,WPU乳液粒径逐渐增加,黏度逐渐下降,表面张力逐渐增大;WPU胶膜的拉伸强度逐渐提高,断裂伸长率逐渐减小。     

共聚低热膨胀聚酰亚胺薄膜的制备与表征

以4,4′-(六氟异丙烯)二酞酸酐(6FDA)为含氟二酐,4,4′-二氨基-2,2′-双三氟甲基联苯(TFMB)为含氟二胺,通过引入分子结构相对对称的刚性单体1,2,4,5-均苯四甲酸二酐(PMDA)进行共聚合成了5种含氟比例不同的透明聚酰亚胺薄膜,并对其性能进行了表征。分析表明:引入刚性单体共聚后薄膜的热稳定性和耐热性有所提高;薄膜的介电常数随着PMDA含量的上升而增加;共聚薄膜在可见光领域的透光率低于均聚薄膜;拉伸实验显示在添加少量PMDA后,薄膜的拉伸强度和弹性模量有所增大,但当PMDA含量过高时其力学性能反而下降;随着PMDA含量的增加,薄膜的热膨胀系数明显降低。     

高度支化聚氨酯-酰亚胺的合成与性能

以异佛尔酮二异氰酸酯(IPDI)、聚碳酸酯二醇(PCDL)、3,3′,4,4′-二苯甲酮二酐(BTDA)和聚醚胺(ATA)为原料,采用A2+B3法合成了具有高度支化结构的聚氨酯-酰亚胺(HBPUI)。通过红外光谱(FT-IR)对结构进行了表征。采用旋转黏度计、差式扫描量热分析(DSC)、热重分析(TGA)、电子拉力机对产物的性能进行了测试。结果表明,与线性聚氨酯-酰亚胺(LPUI)相比,HBPUI具有较低的黏度和较高的Tg;HBPUI的热分解温度达到300℃以上,与高度支化聚氨酯相比,热稳定性得到明显提高;力学测试表明,HBPUI的拉伸强度随硬段含量和[A2]/[B3]的增大而增大,而断裂伸长率呈下降趋势。     

MDI-50型水性聚氨酯的合成及应用

以2,4’-二苯基甲烷二异氰酸酯和4,4’-二苯基甲烷二异氰酸酯的混合物(MDI-50)为硬段,二羟甲基丙酸(DMPA)为水性扩链剂,聚碳酸酯二醇(PCDL)和聚丙二醇(PPG)为软段,合成了一系列的单组分水性聚氨酯乳液;研究了-NCO与-OH的摩尔比、DMPA的含量以及PCDL与PPG质量比对固化胶膜力学性能的影响,并将其涂覆在棉织物表面后,对涂层织物进行了扫描电镜观察、表面接触角测试。结果表明,随着-NCO与-OH的摩尔比、DMPA的含量以及PCDL与PPG质量比的增大,胶膜的拉伸强度都随之增大,断裂伸长率都随之减小;而涂覆有水性聚氨酯乳液的织物表面形貌平整,且接触角均大于90°,表现出良好的疏水性。     

基于聚四氢呋喃的形状记忆聚氨酯的合成及形状记忆性能

采用两步法合成了以聚四氢呋喃(PTMG)为软段,4,4′-二苯基甲烷二异氰酸酯(MDI)、扩链剂2,2-二羟甲基丙酸(DMPA)和封端剂4-(2-(吡啶-4-基)乙烯基)苯酚为硬段的形状记忆聚氨酯(PTMGUs)。通过傅里叶变换红外光谱和核磁共振氢谱等表征了其结构,将聚氨酯制成薄膜后,分别通过热重分析、差示扫描量热及循环拉力动态力学分析等测试研究了硬段含量对其热性能和形状记忆性能的影响,摄像记录其形状回复过程。结果表明,不同硬段含量的PTMGUs都具有较好的形状记忆性能,4次重复形状记忆循环中PTMGUs的平均固定率与回复率都高于90%,其中PTMGU3(硬段质量分数为35%)的形状记忆性能最佳,平均固定率达到96.9%,平均回复率达到99.5%。     

生物基热塑性聚氨酯弹性体合成及性能研究

以二聚二醇(Pripol 2033)、二苯基甲烷二异氰酸酯(MDI)和六取代脂肪酸蔗糖酯(Sefose 1618U B6)为原料,通过两步法合成了嵌段共聚聚氨酯弹性体。用热重分析仪和差示扫描量热仪研究了生物基聚氨酯弹性体的热稳定性及玻璃化转变温度,并采用拉伸实验测定材料的机械性能。结果表明:随着Sefose 1618U B6含量的增加,聚氨酯弹性体的拉伸强度和硬段玻璃化转变温度都随之降低,而断裂伸长率和回弹性却逐渐增强。     

共聚制备低热膨胀透明聚酰亚胺薄膜

为了在尽量不影响其透光性的前提下解决含氟聚酰亚胺薄膜热膨胀系数(CTE)过大的问题,以4,4′-(六氟异丙烯)二酞酸酐(6FDA)、4,4′-二氨基-2,2′-双三氟甲基联苯(TFMB)和3,3′,4,4′-联苯四羧酸二酐(BPDA)为原料,通过两步法合成了5种BPDA掺杂量分别为0、10%、20%、30%和40%的共聚PI薄膜,并采用红外光谱分析(IR)、热重分析(TGA)、热机械性能分析(TMA)等方法对其性能进行了表征.分析表明:共聚薄膜的热性能相比均聚薄膜有所提高;薄膜的介电常数与BPDA的含量成正比,而其在可见光领域的透光率与BPDA的含量成反比;在BPDA含量较低时,薄膜的拉伸强度和弹性模量随BPDA含量的增加而增大,但当BPDA摩尔分数超过30%时其力学性能开始降低;随着共聚单体含量的上升,薄膜的热膨胀系数大幅减小.     

聚二甲基硅氧烷-水性聚氨酯的合成与性能

为了提高水性聚氨酯的耐水性和耐候性,文中以羟烷基聚二甲基硅氧烷(PDMS)和聚己二酸丁二醇酯二醇(PBA)为混合软段,间苯二亚甲基二异氰酸酯(XDI)和1,4-丁二醇(BDO)、二羟甲基丙酸(DMPA)为硬段,采用二步本体法合成一系列的聚二甲基硅氧烷-水性聚氨酯(Si-XWPUs),研究了PDMS在软段中的含量对水性聚氨酯的表面性能、力学性能和耐水性的影响。研究发现,随着PDMS在软段中的含量从0%到20%逐渐增加,Si-XWPUs的微相分离程度略有提高,拉伸强度均达到10 MPa以上,作为涂层材料均具有较好的力学性能。同时,随PDMS在软段中比例的升高,Si-XWPUs薄膜表面Si元素的百分比呈增加趋势,并且表面的Si/C含量远远高于本体中理论Si/C含量,最高的迁移率达24倍,表现出良好的疏水性,同时吸水率降低。     

一种硅氧烷杂化聚氨酯弹性体的制备及动态力学性能

用4,4′-二苯基甲烷二异氰酸酯(MDI)、聚四氢呋喃醚二醇和γ-氨丙基三乙氧基硅烷(KH550)为主要原料,制备出新型硅氧烷杂化聚氨酯弹性体。通过红外光谱,动态力学分析,原子力显微镜等研究了产物的结构及性能。结果表明,不同于传统二胺或二醇扩链的聚氨酯弹性体硬段晶区的片层结构,硅氧烷杂化聚氨酯弹性体硬段区为三维网络状结构,受力时不易破碎和滑移,其软段玻璃化转变温度较4,4′-二氨基二苯甲烷(MDA)扩链型弹性体向低温方向移动9℃,具有更完整的相分离程度和更低的力学损耗。     

一种含能热塑性聚氨酯弹性体的性能

采用熔融二步法合成了以聚叠氮缩水甘油醚(GAP)为软段、以2,2-二叠氮甲基-1,3-丙二醇和二环已基甲烷二异氰酸酯(HMDI)为硬段的含能热塑性聚氨酯弹性体(ETPUE),通过红外光谱(FT-IR),差示扫描量热(DSC),动态力学性能测试(DMA)及力学性能测试对材料进行了结构和性能的表征.结果表明,所合成的不同硬...     

Preparation and properties of adjacency crosslinked polyurethane---urea elastomers

Adjacency crosslinked polyurethane--urea (PUU) elastomers with different crosslinking density were prepared by using hydroxyl-terminated liquid butadiene-nitrile (HTBN), toluene diisocyanate (TDI) and chain extender 3,5-dimethyl thio-toluene diamine (DMTDA) as raw materials, dicumyl peroxide (DCP) as initiator, and N,N'-m-phenylene dimaleimide (HVA-2) as the crosslinking agent. The influences of the crosslinking density and temperature on the structure and properties of such elastomers were investigated. The crosslinking density of PUU elastomer was tested by the NMR method. It is found that when the content of HVA-2 is 1.5%, the mechanical properties of polyurethane elastomer achieve optimal performance. By testing thermal performance of PUU, compared with linear PUU, the thermal stability of the elastomers has a marked improvement. With the addition of HVA-2, the loss factor tanδ decreases. FT-IR spectral studies of PUU elastomer at various temperatures were performed. From this study, heat-resistance polyurethane could be prepared, and the properties of PUU at high temperature could be improved obviously.     

哌嗪扩链的形状记忆医用材料聚氨酯脲的合成与表征

研究了以二元环状仲胺哌嗪(PPZ)替代二元伯胺作为扩链剂,以六亚甲基二异氰酸酯(HDI)为偶联剂,以端羟基聚(丙交酯-co-对二氧环己酮)(HO-P(LA-co-PDO)-OH)为软段,采用溶液法合成了一系列新型聚氨酯脲(P(LA-co-PDO)-PPZ-PUU)。1 HNMR表征结果证实了P(LA-co-PDO)-PPZ-PUU的结构。比较了以PPZ和BDA为扩链剂时两反应体系的粘度变化,产物在氯仿中的溶解性、热熔性及其玻璃化转变温度(Tg)随NCO/OH摩尔比的变化。同时研究了其形状记忆性能。结果表明,PPZ反应体系的粘度更低,产物的溶解性和热熔性更好,PPZ可明显减少交联;而且,PPZ的环状结构可明显提高PUU硬段的刚度,从而提高Tg。形状回复时间受温度的影响,回复温度越高,形状回复时间越短。该材料呈现良好的形状记忆性能且形状回复率均可达到95%以上。     

Preparation of radiopaque polyurethane–urea/graphene oxide nanocomposite using 4-(4-iodophenyl)-1,2,4-triazolidine-3,5-dione

New radiopaque nanocomposites were prepared based on iodinated polyurethane–urea (PUU) and graphene oxide (GO). The iodinated PUU was synthesized using 4,4′-methylenediphenyl diisocyanate (MDI), polyethylene glycol (PEG, Mn?=?1000), and 4-(4-iodophenyl)-1,2,4-triazolidine-3,5-dione (IUr) as a novel chain extender and radiopacifying agent. The synthesized urazole, PUU, and the related nanocomposites are characterized by fourier transform infrared spectrum, nuclear magnetic resonance, X-ray diffraction, field-emission scanning electron microscopy, elemental analysis (CHNO), thermogravimetric analysis, and dynamic mechanical thermal analysis (DMTA). The X-ray visibility of the radiopaque PUU and nanocomposites was investigated using X-radiography. To evaluate the biocompatibility of the samples, the indirect MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay was carried out on the non-cancerous mouse fibroblast cell line NIH3T3 D4 according to the ISO10993-5 standard. The DMTA results proved introduction of the GO layers into the iodinated PUU matrix, and has improved mechanical properties of the nanocomposites compared to the pure polymer. The X-ray images showed significant radiopacity of the pure polymer and the nanocomposites.     

TDI三聚体的合成及其在弹性体中的应用

以2,4-甲苯二异氰酸酯（TDI）为原料成功合成出了TDI三聚体,并用三聚体合成出了以聚醚二醇（PTHF）为基体的PUU弹性体。结果表明：TDI三聚反应的最佳条件为：反应温度为50℃,催化剂浓度0．05％。在三聚反应进程中,随着反应进度的增加,体系中残余NCO的含量逐渐降低,三聚化程度逐渐提高。用三聚体改性的材料拉伸强度、扯断伸长率和永久变形都有不同程度的下降;在热失重30％时的分解温度提高了约20℃,这对于改善材料在高温下的性能提供了新的思路。     

硬段模型化合物对聚氨酯型固体电解质的影响

以聚醚聚氨酯，高氯酸钠和硬段模型化合物为组分，制备了一系列新型的聚合物固体电解质，利用FT-IR，DSC，TG及复阻抗谱分析对该体系进行了表征。结果表明，当盐浓度保持恒定时，硬段模型化合物对所研究体系的形态，离子-聚合物间相互作用，玻璃化转变温度，软段热分解温度和离子导电特性的有显著的影响。随着硬段模型化合物含量的增加，体系中钠离子与醚氧基团间的络合程度增加。玻璃化转变温度和软段热分解温度上升，聚氨酯硬段的聚集体出现。所有这些均导致该固体电解质的电导率下降。     

Preparation and properties of poly HTBN-based urethane--urea/organo reactive montmorillonite nanocomposites

With ultrasonic assistant mixing way, an intercalated mixture of polyol/organo reactive montmorillonite (ORMMT) was pretreated. The prepolymer composed MMT clay was prepared by reaction of polyol/ORMMT mixture with toluene diisocyanate (TDI). The resultant prepolymer reacted with extender (DMTDA) and then the polyurethane--urea/organo reactive montmorillonite (PUU/ORMMT) nanocomposites were obtained. The structure, morphology and properties of PUU/ORMMT nanocomposites were characterized by FT-IR, TEM, AFM, strain-stress machine, TGA, and dynamic mechanical analysis (DMA). The results showed that when the OMMT content is 3%, the PUU/ORMMT nanocomposities performed super mechanical properties. Because of the presence of ORMMT, both T_g of the soft segment and tanδ of the PUU increased, and the decomposition temperature for the first step and the second step increased respectively. TEM images showed that the organophilic MMT particles in the PUU composite exhibit a high degree of intercalation and exfoliation.     

交联对聚氨酯脲弹性体的结构与性能影响

化学交联键的存在使得极性基团间的氢键化作用减弱,氢键化的NH吸收位置（3280cm^-1）向高波数（3290cm^-1）方向移动,羰基区内完全有序的氨酯羰基（1693cm。）吸收谱带观察不到,脲羰基吸收谱带（1643cm^-1）变得较弱。交联点越多,回弹性越小,压缩生热越大。交联PUU弹性体的硬度在同温度下高于线性PUU的硬度。随着温度的升高,交联PUU的回弹性增加速度高于线性PUU的增加速度,交联PUU的硬度减少速度高于线性PUU的减少速度。     

Effects of chain extender and hard/soft segment content on the surface and electrical properties of PDMS based polyurea-urethane

A series of PDMS based Poly(urea-urethane) (PUU) polymers with various polar functional groups on their side chains have been prepared by using a prepolymer process. The hydrophilic and hydrophobic characters of PUU films have been investigated. It was found that PUU film possesses different surface properties on the aluminum contacting face and on the air contacting face. Results show that the differences of contact angles between two sides of the PUU film are very significant. Results also indicate that the silicone/nitrogen ratio on the aluminum-contacting surface is higher than that on the air-contacting surface, and the ratio decreases as the hard segment content increased. It was also found that when the sample was in a dry condition, the electrical surface resistance is in the range of 10¹⁴ . However, when the sample was conditioned at 70%, 80% and 100% R.H., the electrical surface resistance decreases to 10⁸ .     

Investigation of kinetics and morphology development for polyurethane-urea extended by DMTDA

The relationship between the reactions kinetics and morphology development during the polyurethane-urea (PUU) curing process has been investigated simultaneously by in situ Fourier transform infrared spectroscopy (FTIR). The data of the FTIR spectra showed that with the increase of conversion, the absorbance of NH bands increases and its band sites shifts to lower wavenumbers; the absorbance of free urethane carbonyl kept nearly constant at low conversion, and then decreased much because of the interaction of the formed urea links, and then changed little at high conversion owing to the diffuse control. The band sites of hydrogen bonded urea carbonyl similarly shifted to lower wavenumbers and the absorbance of the hydrogen bonded urea carbonyl, associated with the phase separation of hard segments, became stronger with buildup of hydrogen bond between urea links. The carbonyl bands available during curing process were further assigned. Both interactions, such as hydrogenised effect and phase separation, played a major role in the matrix formation of the PUU polymer.