基于二硫键的自修复水性聚氨酯的制备与性能研究

以芳香二硫化合物2,2'?二氨基二苯二硫醚（AD）为原料,制备了一种自愈性水性聚氨酯（WPU）材料。利用全反射傅里叶变换红外光谱仪、拉曼光谱仪、热失重分析仪、粒径分析仪、热台偏光显微镜和接触角仪对改性材料进行了结构表征与性能测试,探讨了聚氨酯材料的热稳定性、表面疏水性、自修复性能的变化。另外,通过拉伸测试,定量评价了材料的拉伸性能和自愈合效率。结果表明,AD成功引入到WPU分子链中;随着AD含量的增加,改性材料的热稳定性逐渐下降;表面疏水性提升,样品WPU?3的静态接触角达到了81.2 °;拉伸强度由WPU?0的1.1 MPa增至WPU?3的5.6 MPa;同时,在中等愈合温度（80 ℃）下,样品WPU?1加热3 h后可以使拉伸应变的愈合效率达到81 %左右。     

羟丙基壳聚糖/氧化甲基纤维素自愈合水凝胶的制备及其载药性能

采用高碘酸钠对甲基纤维素（MC）进行氧化制备了氧化甲基纤维素（DAMC），通过羟丙基壳聚糖（HPC）的氨基与DAMC的醛基发生希夫碱反应制备了HPC/DAMC自愈合水凝胶。通过调节HPC和DAMC含量探究水凝胶的微观形态、溶胀性能、力学性能、自愈合性能、体外降解以及药物缓释性能。结果表明，HPC/DAMC自愈合水凝胶具有相互连通的孔隙，且孔径处于80～375μm范围内，在室温无刺激条件下能够在20 min内实现自愈合且具有良好的拉伸性能。此外，HPC/DAMC自愈合水凝胶具有良好的保水性，其溶胀比为14.0～17.4。在溶菌酶的作用下，HPC/DAMC自愈合水凝胶在60 h时质量损失率可达84.2%～99.6%。HPC/DAMC自愈合水凝胶对抗肿瘤药物吉西他滨具有缓释效果，缓释作用长达96 h，药物累积释放率达到83.2%～92.7%。     

聚氨酯-Ch水凝胶的制备及其作为伤口敷料的性能

以2,4-二羟基苯甲醛(DDBA)为扩链剂,丙烯酸羟乙酯(HEA)为封端剂制备了含有醛基的水性聚氨酯(DPU),在温和的条件下引入不同含量的羧甲基壳聚糖(CMCh)溶液合成了CMCh席夫碱,接着其与丙烯酰胺经自由基反应合成了聚氨酯-羧甲基壳聚糖席夫碱水凝胶(DPU-Ch).通过FTIR、SEM、力学性能、溶胀保水性、抗菌性和血液相容性测试等对水凝胶结构和性能进行了表征.结果表明,水凝胶的机械性能随着CMCh含量的增加先增大后减小,水凝胶显示出良好的溶胀能力和保水能力;水凝胶对革兰氏阳性和阴性细菌菌株均显示出良好的抗菌性能;水凝胶溶血率均低于5％,表明其具有良好的细胞相容性,小鼠成纤维细胞(NIH3T3)存活率在90％以上证明其细胞毒性较低.当CMCh添加量为DPU树脂固含量的4％时,DPU-Ch水凝胶综合性能最佳,溶胀比为10.58,24 h失水率为31.1％,压缩强度为0.70 MPa,溶血率为2.4％,细胞存活率为101％±1.7％,抗菌性能良好.     

两种新型席夫碱-Mn(Ⅱ)配合物-壳聚糖复合材料的合成表征及其SOD活性

以二乙烯三胺、三乙烯四胺分别与间苯二醛反应合成二乙烯三胺-间苯二醛席夫碱(L1)、三乙烯四胺-间苯二醛席夫碱(L2),然后与醋酸锰反应合成了两种席夫碱-Mn(Ⅱ)配合物,进而与壳聚糖凝胶反应合成了两种席夫碱-Mn(Ⅱ)配合物-壳聚糖复合材料L1-Mn(Ⅱ)-壳聚糖和L2-Mn(Ⅱ)-壳聚糖,对其结构进行了傅立叶变换红外光谱(FTIR)、扫描电子显微镜(SEM)及X-射线光电能谱(XPS)表征,采用氯化硝基四氮唑蓝(NBT)法测定两种复合材料的SOD活性,并对它们的重复利用性进行了测试。FTIR、SEM及XPS表征结果表明,配合物与壳聚糖成功交联;L1-Mn(Ⅱ)-壳聚糖、L2-Mn(Ⅱ)-壳聚糖的IC50分别为3.40μg·mL-1、6.15μg·mL-1,都具有较好的SOD活性;两种材料稳定且具有较好的重复利用性。     

室温交联单组分聚氨酯-聚丙烯酸酯乳液的合成

分别合成了带有端酰肼基的自乳化型聚氨酯乳液和带酮羰基侧链的聚丙烯酸酯乳液，将两种乳液混合复配成在室温下可长期稳定储存的乳液，应用时两种树脂的活性基团在室温发生交联反应得到聚氨酯交联的聚丙烯酸酯复合树脂。合成聚氨酯乳液的较好工艺是：反应温度约60℃，反应时间=6h，n（OH)／n(NCO)=0．85，W(—COOH)=3％，二羟甲基丙酸(DMPA)以丙酮提取法加入；分析了乳液的粒径分布和稳定性；用红外谱图证明在室温发生了交联反应 ；测试了复合树脂的某些机械性能和耐溶剂性。     

2,2-二羟甲基庚酸的合成与表征

以2,2-二羟甲基庚醛为原料,双氧水为氧化剂,经氧化反应合成了2,2-二羟甲基庚酸。产物结构用红外光谱(IR)、核磁共振氢谱和碳谱表征。结果表明,氧化反应的最佳工艺条件为:体系的pH值为4,水与2,2-二羟甲基庚醛的质量比为3∶1,过氧化氢和2,2-二羟甲基庚醛的物质的量之比为1.1∶1,反应温度为70℃,反应时间为8 h,产物的收率为57.6%。     

聚氨酯-羧甲基壳聚糖席夫碱水凝胶的制备与性能

将2,4-二羟基苯甲醛（DDBA）作为扩链剂，丙烯酸羟乙酯(HEA)作为封端剂制备了含有醛基的水性聚氨酯（DPU），在温和的条件下引入羧甲基化壳聚糖（CMCh）合成了聚氨酯-CMCh席夫碱，再由自由基聚合法引入聚丙酰胺合成了聚氨酯-羧甲基壳聚糖席夫碱水凝胶（DPU-Ch）。通过FTIR、SEM、力学性能、溶胀保水试验、抗菌试验和血液相容性测试等对水凝胶结构和性能进行表征。结果表明，水凝胶的机械性能随着CMCh质量分数的增加而提升，同时水凝胶也显示出良好的溶胀能力和保水能力；当CMCh添加量为2%时，水凝胶对革兰氏阳性和阴性细菌菌株均显示出良好的抗菌性能；水凝胶溶血率均低于5%表明其具有良好的细胞相容性，NIH3T3细胞存活率在90%以上证明其没有细胞毒性，因此在生物医疗领域中具有潜在的应用前景。     

基于生物质的活性医学胶黏剂用聚氨酯的合成与性能研究

研究了以植物油为主要原料,制备一种流动性好、可室温快速固化、具有良好的柔韧性和粘结性能的医学胶黏剂用聚氨酯。首先,将蓖麻油在一定的反应条件下皂化水解,合成蓖麻油脂肪酸;然后用制得的蓖麻油脂肪酸与环氧大豆油,以三乙胺与1-甲基咪唑为催化剂,对环氧基团进行开环反应,制备绿色植物油多元醇;再加入高活性的六亚甲基二异氰酸酯,利用植物油多元醇合成过程中加入的催化剂的作用,催化异氰酸酯的-NCO基与多元醇的-OH基之间的聚合反应,制得完全无毒、不含溶剂的活性聚氨酯低聚物。通过实验确定合成过程的反应条件,并通过红外光谱、表干时间、附着力测试对聚氨酯的性能进行表征。实验结果表明反应时间为2 h,反应温度70℃,NCO/OH=1.60时,能制得性能优良的医学胶黏剂用聚氨酯。测试结果表明:通过上述条件合成的聚氨酯的表干时间为12 h,附着力为1级,傅里叶红外测试表明合成产物为聚氨酯。     

偕二硝基不敏感增塑剂的合成与性能

2,2-二硝基丙醇分别与乙酸、丙酸、正丁酸经酯化反应,合成2,2-二硝基丙醇乙酸酯、2,2-二硝基丙醇丙酸酯、2,2-二硝基丙醇丁酸酯三种新型偕二硝基酯类增塑剂。利用FTIR、NMR和元素分析等对偕二硝基酯类增塑剂进行了结构表征;考察了催化剂浓硫酸用量、反应物料比及反应时间对产物收率和纯度的影响。结果表明,2,2-二硝基丙醇乙酸酯较佳合成条件为:浓硫酸用量3%,2,2-二硝基丙醇与乙酸摩尔比为1∶1.10,酯化反应时间6 h。测试了所合成的三种新型增塑剂的密度、热分解温度、玻璃化转变温度、感度等性能,并计算了生成焓和溶解度参数。其中2,2-二硝基丙醇乙酸酯的性能如下:密度1.319 g/cm~3,溶解度参数20.994 J~(1/2)/cm~(3/2),玻璃化转变温度-94.4℃,热分解峰温为254.9℃,生成焓414.5 kJ/mol,摩擦感度4%,撞击感度H_(50)125.9 cm。     

2,2-二羟甲基十二酸的合成

研究了以月桂醛(正十二醛)、甲醛、过氧化氢为原料,经羟醛缩合、过氧化氢氧化合成2,2-二羟甲基十二酸的方法,探讨了原料摩尔比、催化剂或氧化剂用量、反应温度和时间对羟醛缩合反应和氧化反应的影响。结果表明,月桂醛(正十二醛)与甲醛摩尔比为2.6∶1.0、催化剂与月桂醛摩尔比为0.51∶1.0、羟醛缩合反应温度为50℃、反应时间为3 h,合成的2,2二-羟甲基十二醛收率为46%;H2O2与2,2二-羟甲基十二醛摩尔比为1.1∶1.0,氧化反应温度为70℃、反应时间为7 h,合成的2,2二-羟甲基十二酸收率为86%。并用13C和1H核磁共振谱表征了2,2-二羟甲基十二酸的结构。     

一种基于动态双硫键的自修复聚氨酯弹性体的制备与性能

以聚丙二醇(PPG)、异佛尔酮二异氰酸酯(IPDI)和含硫扩链剂胱氨酸二甲酯(CDE)为原料,固定摩尔比为1∶3∶2,采用预聚体法制备含硫自修复聚氨酯弹性体(SPU),对SPU进行红外光谱测试、拉曼光谱测试、力学性能和自修复性能测试、划痕修复观察和DSC测试。结果表明,SPU为非晶结构,微相分离程度低;切割50%深度后,通过拉伸强度测试得出其在60℃的自修复效率达到89.8%,原因是动态双硫键的交换反应和分子链的高运动能力(硬段玻璃化转变温度<60℃)。     

基于双硫键和氢键协效的高性能自修复聚氨酯脲的研制

为解决自修复弹性体同时具有优异的力学性能和自修复性能的矛盾,首先将原料胱氨酸（CYS）进行甲酯化得到含双硫键的二胺扩链剂胱氨酸二甲酯（CDE）,然后以聚四氢呋喃醚二醇（PTMG）为软段,异佛尔酮二异氰酸酯（IPDI）和CDE为硬段,固定摩尔比为1∶3∶2,采用两步法制备了自修复聚氨酯脲（SH-PUU）弹性体,并对SH-PUU进行了红外光谱测试、拉曼光谱测试、力学性能测试、自修复性能测试、划痕修复微观形貌观察、应力松弛和动态力学性能测试。实验结果表明：SH-PUU的软段和硬段的玻璃化转变温度分别为-38.5℃和77.6℃,微相分离程度较高,SH-PUU具有良好的力学性能,拉伸强度为13.6MPa,断裂伸长率达531.3%;同时SH-PUU具有高效的自修复能力,试样在经过80℃修复2h后,基于拉伸强度的自修复效率达到97.1%,SH-PUU的力学性能和自修复性能达到较好的平衡。SH-PUU的高自修复能力是由动态双硫键和氢键协效增强引起的,其通过加热方式的自修复机理为：SH-PUU中的动态双硫键在80℃发生可逆交换反应,SH-PUU中的氢键在低于100℃时会重新形成。     

High-efficiency self-repairing polyurethane based on synergy of disulfide bonds and graded hydrogen bonds

Designing an elastomer that possesses both mechanical strength and self-healing properties is a challenging. In this study, a polyurethane elastomer (PUSTP) was successfully synthesized, featuring disulfide bonds along the main chain and graded intermolecular hydrogen bonds. The results demonstrated that the mechanical properties of the polyurethane elastomer improved with an increase in the number of disulfide bonds increased. Specifically, when the molar ratio of disulfide bonds to IPDA was 5:5, the tensile strength of the composite elastomeric film was 5.22 MPa, with an elongation of 1820.26%. Furthermore, the material exhibited robust thermal stability after undergoing repair at 70°C for 12 h, the mechanical strength of the polyurethane membrane remained unchanged, showing outstanding self-healing capabilities. Additionally, the polyurethane film served as the substrate material for crafting self-healing conductive devices, which maintained excellent electrical conductivity even after damage repair. This flexible material, combining impressive mechanical recovery capabilities with electrical performance, holds significant promise for a wide array of applications.     

新型视黄基席夫碱盐的合成与吸波性能研究

以维生素A乙酸酯为原料,通过水解、活性二氧化锰氧化得视黄醛,醛与联苯胺反应合成席夫碱,席夫碱掺杂金属银化合物制得新型视黄基席夫碱盐。研究了活性二氧化锰氧化试剂对产物产率的影响,并通过元素分析、红外光谱等对产物结构进行了表征。结果表明,以活性二氧化锰为氧化剂,在常温下氧化反应26 h；合成视黄基席夫碱银盐的条件为80℃,反应4 h；在2～18 GHz范围内测定掺杂银盐的吸波性能,最好的反射率为～16 dB。     

Multi-functional polyurethane composites with self-healing and shape memory properties enhanced by graphene oxide

Development of shape memory polymer materials with integrated self-healing ability, shape memory property, and outstanding mechanical properties is a challenge. Herein, isophorone diisocyanate, polytetramethylene ether glycol, dimethylglyoxime, and glycerol have been used to preparation polyurethane by reacting at 80°C for 6 h. Then, graphene oxide (GO) was added and the reaction keep at 80°C for 4 h to obtain polyurethane/GO composite with self-healing and shape memory properties. Scanning electron microscopy shows that the GO sheets were dispersed uniformly in the polyurethane matrix. The thermal stability was characterized by thermogravimetric analyses. The tensile test shows that the Young's modulus of the composites increases from 38.57 ± 4.35 MPa for pure polyurethane to 95.36 ± 10.35 MPa for the polyurethane composite with a GO content of 0.5 wt%, and the tensile strength increases from 6.28 ± 0.67 to 15.65 ± 1.54 MPa. The oxime carbamate bond and hydrogen bond endow the composite good self-healing property. The healing efficiency can reach 98.84%. In addition, the composite has excellent shape memory property, with a shape recovery ratio of 88.6% and a shape fixation ratio of 55.2%. This work provides a promising way to fabricate stimulus-responsive composite with versatile functions.     

Application of EIS and EN techniques to investigate the self-healing ability of coatings based on microcapsules filled with linseed oil and CeO2 nanoparticles

Microcapsules with urea–formaldehyde as the shell and linseed oil as the healing agent were synthesized by a previously reported procedure. Two kinds of synthesized microcapsules, without and with CeO₂ nanoparticles, were separately added to the epoxy resin coatings. The epoxy coatings containing microcapsules were applied on carbon steel, and their self-healing effect was investigated in 0.5 M HCl solution. The amount of the released healing agent that filled up the scratch was estimated by scratch filling efficiency (SFE). The SFE values are only the theoretical estimates of the self-healing performance. The scratch sealing efficiency (SSE), which is a measure of corrosion protection performance of the damaged coating, can be measured by electrochemical impedance spectroscopy (EIS) and electrochemical noise (EN) techniques. For sake of an optimum self-healing system, two series of coatings, with and without nanoparticles, were prepared by using different microcapsule concentrations: 5, 10, 15 and 20 wt%. For comparison, a coating without microcapsules was also prepared. The coated samples with 5% microcapsule concentration, due to the low amount of released linseed oil, could not properly repair the artificial scratch. In contrast, when the microcapsule concentration was equal to or higher than 10% the volume of the released linseed oil was enough to seal the scratch. However, the coating sample containing 15% nanoparticle-loaded microcapsules was the optimum self-healing coating because it showed comparable SSE values to those of samples containing 20% microcapsule concentration in spite of its lower microcapsule concentration. The EN method was employed as a complementary quantitative technique to study the self-healing behavior of coatings. The calculation of the amount of noise charges using the standard deviation of partial signal (SDPS) plots arising from wavelet analysis made it possible to obtain the SSE values of the coatings. The good agreement between EIS and EN results indicates that the EN technique, as well as the EIS method, can be used successfully for the self-healing evaluation.     

新型二醛化合物及其希夫碱的合成、表征

以4-羟基-3-甲氧基苯甲醛和1,4-二溴丁烷为原料,在乙腈溶液中合成了双-（2-甲氧基-4-甲酰基苯基）-1,6-二氧杂己烷,通过H^1NMR、FT-IR进行了结构表征,用X射线单晶衍射测定了该醛的晶体结构。并且合成了该醛的三种新型希夫碱。结果表明：该双醛以中间的C—C键为对称中心,由中间四个碳连接的两个苯环共平面;该化合物属于单斜晶系,空间群为P2（1）／c,晶胞参数为：a=0．74108（15）nm,b=0．76500（15）nm,c=1．6406（3）nm,β=95．762°（4）,V=0．9254（3）nm^3,Z=2,最终的一致性因子为R=0．0551,wR2=0．1541。     

Transparency-tunable and moderate-temperature healable thermoplastic polyurethane elastomer based on bisphenol A chain-extender

Transparent self-healing polymers have a promising future, but the research on the relationship among transparency, self-healing, and structure is still challenging. The thermoplastic polyurethane elastomers containing aryl carbamate were prepared by the reaction of isocyanate-terminated prepolymer and chain-extender bisphenol A (BPA). On the one hand, the thermoplastic polyurethane elastomer could heal at a relatively low temperature due to the exchange of aryl carbamate, and exhibits 83% of healing efficiency at 90°C for 2 h. On the other hand, two methyl groups of BPA hinder the crystallization of hard segments in polyurethane, so the domain of hard segments is amorphous, while the microcrystals of soft segments dispersed in the polyurethane are affected by the content of hard segments, therefore, the transparency of polyurethane can be tailored by the content of hard segments. It provides a simple design and a feasible preparation method for transparent self-healing polymer.     

基于两种双硫键自修复聚氨酯制备及性能

以异佛尔酮二异氰酸酯(IPDI)和双(2–羟基乙基)二硫醚(DTBO)为硬段,聚四氢呋喃(PTMG)为软段,β–巯基乙醇(ME)为封端剂,制备巯基封端且含双硫键的聚氨酯(PUR)预聚物,利用巯基易氧化的特点,用H2O2/NaI进行氧化,合成分子链内和分子链端均含有双硫键的自修复交联PUR。采用傅立叶变换红外光谱仪、差示扫描量热仪、热重/差热综合热分析仪和电子拉力试验机等手段,研究了PUR的结构及PTMG与ME的物质的量之比对PUR热性能、力学性能和自修复性能的影响。结果表明,合成的系列交联PUR都具有一定的自修复能力和良好的热性能,当DTBO和PTMG物质的量分数分别为总二元醇的40%和60%时,PUR的拉伸强度达到最大值,为2.6 MPa,在60℃热处理8 h条件的自修复率为80.8%,且该试样经三次自修复后,自修复率仍可达到50.0%。