离子液体交联水凝胶的性能及除锈应用研究

合成了离子液体甲基丙烯酸二甲氨基乙酯顺丁烯二酸盐（DMAEMA-MA），并作为交联剂应用于2-丙烯酰胺-2-甲基丙烷磺酸（AMPS）和丙烯酰胺（AAm）的交联聚合，制备了水凝胶IC-P(AMPS-co-AAm)。以N,N''-亚甲基双丙烯酰胺（BIS）为非离子交联剂制备了水凝胶BIS-P(AMPS-co-AAm)，与IC-P(AMPS-co-AAm)的性能进行了比较。通过SEM发现IC-P(AMPS-co-AAm)具有与BIS-P(AMPS-co-AAm)相似的孔道结构，当DMAEMA-MA的添加量为1.6%时，在水中的溶胀率可以达235.97%，同时电导率达到58.8μS/cm。热重分析（TGA）表明，DMAEMA-MA能提高IC-P(AMPS-co-AAm)的热稳定性。考察了不同DMAEMA-MA含量的IC-P(AMPS-co-AAm)与BIS-P(AMPS-co-AAm)的除锈性能，结果表明，当DMAEMA-MA含量为1.6 wt%时，对锈蚀等级为C级的Q235低碳钢除锈效果可达A级。     

聚氯乙烯的离子型热可逆交联研究

通过二胺的烷基化反应，制备了不同链长的二叔胺，利用二叔胺与聚氯乙烯(PVC)链上的活性氯形成季铵盐离子键的反应，制备了具有离子型热可逆交联特性的PVC。在研究中发现，对于硬聚氯乙烯(PVC-U)，适当份数的交联剂能够提高材料的杨氏模量、屈服强度、断裂强度和断裂伸长率；应用于软聚氯乙烯(PVC-S)时，断裂强度、断裂伸长率均得到提高，而永久变形量明显降低，并且交联时间的延长对力学性能影响显著。     

Effect of Bio-Based Cobalt Alginate on the Fire Safety and Mechanical Properties for Epoxy Resin

There is a growing demand to develop epoxy resins (EP) with smoke suppression as well as satisfactory flame retardancy. Herein, bio-based cobalt alginate is successfully fabricated and incorporated into EP to prepare EP/Cobalt Alginate composites with better fire safety performance. The addition of cobalt alginate reduces the thermal-decomposition rate, temperature at maximum weight-loss rate of EP, whereas obviously improves the thermal stabilities at a higher temperature range. Furthermore, the addition of cobalt alginate substantially reduces the fire hazard of EP, resulting in 56.2% reduction in peak heat release rate, as well as 17.8% and 56.3% reduction in total smoke production and peak smoke production rate, respectively, compared with EP matrix. Moreover, the presence of cobalt alginate increases smoke-suppressant properties, according to the smoke density test. Additionally, the incorporation of cobalt alginate has no obviously destructive effect on the mechanical properties of EP, while EP/Cobalt Alginate-3 exhibits a 27.0% improvement in impact strength. In prospective, this study may provide a significant method for producing eco-friendly flame retardant EP.     

Synergistic Effects of Iron Alginate on Improving the Fire Safety and Mechanical Properties of Epoxy Resin/Ammonium Polyphosphate Composites

Iron alginate is chosen as an eco-friendly synergist to improve the flame retardancy, smoke suppression, and mechanical properties of epoxy resin/ammonium polyphosphate composites (EP/APP). The suitable additive amount of iron alginate further enhances the char-forming ability in the higher-temperature range and flame retardancy of EP/APP. EP/APP_9.0-iron alginate_1.0 retains a char residue of 33.3% at 700 °C and obtains a limiting oxygen index value of 28.4% and vertical burning test (UL-94) V-0 rating, while EP/APP₁₀ has no UL-94 rating. The burning behaviors of EP/APP_9.0-iron alginate_1.0 are also suppressed; and the total smoke production value is much lower than that of EP/APP₁₀. EP/APP_9.0-iron alginate_1.0 releases less smoke and flammable fragments. The suitable additive amount of iron alginate boosts the mechanical properties of EP/APP, while APP destroys the mechanical properties of EP. Therefore, the addition of suitable amount of iron alginates can further reduce the fire hazard, and improve the mechanical properties of EP/APP composites.     

Dual Cross-Linked Polymethacrylic Acid Hydrogels with Tunable Mechanical Properties and Shape Memory Behavior

Herein, a series of poly(methacrylic acid) hydrogels are prepared via bulk polymerization of methacrylic acid (MAAc) and grafting of Triton X-100 (TX-100). One-pot and extremely simple chemistry consist of only mixing and subsequently heating of commercially available monomer and surfactant. The polymer chains are interconnected through dual physical cross-link points formed by the hydrophobic associations in the center of TX-100 micelles and hydrogen bonds stabilized by hydrophobic α-methyl groups of MAAc. The hydrogels exhibit tunable mechanical properties ranging between softness and stiffness by adjusting the surfactant/monomer molar ratio, such as Young modulus of 0.6−22 MPa, elongation at break of 750−1700%, tensile strength of 0.21−3.6 MPa, and compressive strength of 41−93 MPa. The synergistic effect of high-density hydrogen bonds with hydrophobic associations endows a plastic-like hydrogel with high strength and shape memory (SM) behavior, while a high concentration of micelles with low-density hydrogen bonds endows a stretchable elastic hydrogel. The combination of temperature-induced SM property and wide-ranging mechanical performance will make such hydrogels useful in diverse applications.     

Ionogels Based on Poly(methyl methacrylate) and Metal-Containing Ionic Liquids: Correlation between Structure and Mechanical and Electrical Properties

Ionogels (IGs) based on poly(methyl methacrylate) (PMMA) and the metal-containing ionic liquids (ILs) bis-1-butyl-3-methlimidazolium tetrachloridocuprate(II), tetrachloride cobaltate(II), and tetrachlorido manganate(II) have been synthesized and their mechanical and electrical properties have been correlated with their microstructure. Unlike many previous examples, the current IGs show a decreasing stability in stress-strain experiments on increasing IL fractions. The conductivities of the current IGs are lower than those observed in similar examples in the literature. Both effects are caused by a two-phase structure with micrometer-sized IL-rich domains homogeneously dispersed an IL-deficient continuous PMMA phase. This study demonstrates that the IL-polymer miscibility and the morphology of the IGs are key parameters to control the (macroscopic) properties of IGs.     

Influence of Process Variables on the Physical Properties of Gelatin/SA/HYA Composite Hydrogels

A novel composite hydrogel based on gelatin, sodium alginate (SA) and hyaluronic acid (HYA) was fabricated by freeze-drying method using 1-ethyl-(3-3-dimethylaminopropyl) carbodiimide (EDC) as a cross-linker. The effects of chemical cross-linking, including cross-linker content and cross-linking time, on the morphology, swelling ratio and compressive strength of the gelatin/SA/HYA hydrogel were investigated. The influence of pH value of the swelling medium on the swelling ratio of the gelatin/SA/HYA composite hydrogel was also studied. The results showed that the gelatin/SA/HYA composite hydrogel had a three-dimensional interconnected structure and the pore size decreased with increasing EDC concentration. The IR absorption peak intensity of the gelatin/SA/HYA hydrogel has no obvious variety with increasing EDC content. The swelling ratio of the gelatin/SA/HYA hydrogel decreased with increasing cross-linker content and cross-linking time; however, the compressive strength increased with increasing EDC content and cross-linking time. The hydrogel swelling peak reached at pH 7. Therefore, the architecture and the physical properties of the gelatin/SA/HYA composite hydrogel can be adjusted by controlling the chemical cross-linking conditions and pH value of swelling medium.     

海藻酸/羧甲基纤维素共混膜的结构与性能研究

用溶液共混法制备了海藻酸/羧甲基纤维素共混膜,通过红外光谱、X-射线衍射、原子吸收光谱、扫描电镜、热分析等对共混膜的结构进行了表征,并测定了不同配比共混膜的透光率、拉伸强度、断裂伸长率、水蒸汽透过率和吸水率.结果表明:共混膜中海藻酸和羧甲基纤维素之间具有较强的相互作用和良好的相容性.共混膜具有良好的力学性能,在生物材料...     

热空气老化对丁基橡胶交联密度和力学性能的影响

采用热空气老化试验机研究了丁基橡胶（IIR）的老化行为,获得了不同老化温度和老化时间对IIR交联密度和力学性能的影响规律。结果表明,随着老化时间的延长,IIR硫化胶的交联密度先增大后减小,并随老化温度的升高变化幅度较为明显。拉伸强度、定伸应力和硬度均出现类似变化规律,而拉断伸长率先迅速下降后逐渐趋于平缓。     

离子液体与淀粉基复合抗静电剂在PE-HD中的抗静电和力学性能研究

以离子液体和淀粉基抗静电剂及其复配应用于高密度聚乙烯（PE-HD）中,研究了其在PE-HD材料中的抗静电效果和力学性能。结果表明,离子液体与淀粉基抗静电剂复配后在PE-HD材料中有良好的抗静电效果和良好的耐久性,在一定含量下不会降低PE-HD材料的拉伸强度和缺口冲击强度。     

盐度对N-异丙基丙烯酰胺与丙烯酰胺共聚物性能的影响

采用自由基共聚的方法,合成了温度敏感水凝胶。在不同环境温度测试了N-异丙基丙烯酰胺与丙烯酰胺共聚物的拉伸性能,并且在不同盐度下研究了共聚物的机械性能,试验中发现溶胀与未溶胀的水凝胶在力学性能上的差异。本文还研究了盐度对LCST(最低临界温度)的影响,试验结果表明,改变溶液盐度是一种有效控制水凝胶LCST的方法。     

胶原蛋白/海藻酸/羧甲基纤维素共混膜的结构与性能

利用溶液共混法成功制备了新型生物膜材料—胶原蛋白/海藻酸/羧甲基纤维素共混膜(blend film),通过红外光谱、X-射线衍射、原子吸收光谱、扫描电镜对共混膜的结构进行了表征,同时测定了不同配比共混膜的透光率、拉伸强度(tensile strength)、断裂伸长率(breaking elonga-tion)、吸水率和水蒸汽透过率;对共混膜进行了热重和差示量热扫描分析。结果表明:共混膜中胶原蛋白、海藻酸钠和羧甲基纤维素之间具有较强的相互作用和良好的相容性,Ca2+交联、氢键以及静电引力等强烈相互作用使三元共混膜力学性能等得到了显著改善,其拉伸强度明显高于胶原蛋白膜、海藻酸膜和胶原蛋白/海藻酸二元共混膜、海藻酸钠/羧甲基纤维素二元共混膜,胶原蛋白质量分数为18.1%、海藻酸质量分数为45.5%和羧甲基纤维素为36.4%的三元共混膜中抗张强度最大,达102MPa。三元共混膜具有良好的力学性能,较好的热稳定性,作为一种新型生物材料可望在生物医学和食品材料领域得到应用。     

纳米金刚石对橡胶力学性能的影响

纳米金刚石晶粒细小,小表面积大,可以添加在橡胶中来提高它的力学性能。本文对纳米金刚石添加在天然橡胶、氯橡胶后对其力学性能的影响进行了实验研究,对橡胶老化前后进行了力学性能测试。结果表明,纳米金刚石对天然橡胶的性能基本无影响,对氟橡胶老化前起有利作用,对老化后的氟橡胶基本无影响。     

橡胶改性对PS力学性能的影响及其机理研究进展

通用聚苯乙烯(PS)抗冲击性能较差,综述了三元乙丙(EPDM)、天然橡胶(NR)、丁苯橡胶(SBR)、乙丙橡胶(EPR)等改性聚苯乙烯,并讨论了橡胶改性对聚苯乙烯力学性能的影响和改性机理。     

碳纳米管对硅酸盐水泥力学性能的影响研究

研究了用超声分散的碳纳米管对硅酸盐水泥物理力学性能的影响,并利用XRD和SEM等测试手段对碳纳米管改性水泥的水化产物及硬化浆体的形貌进行了分析.结果表明:碳纳米管的掺入改变了水泥净浆的标准稠度用水量和凝结时间,提高了其抗压和劈裂抗拉强度,但并未造成安定性不良.随碳纳米管掺量的增加,水泥净浆的标准稠度用水量逐渐增加,凝结时间不断缩短,标养28天的抗压和疲劳抗拉强度较未掺碳纳米管的硬化浆体分别提高了15.34％和18.44％.XRD分析表明碳纳米管的掺入不仅提高了水泥净浆的水化程度,增加了C-S-H的生成量,而且降低CH的结晶度.SEM证明碳纳米管的掺入较未掺的水泥净浆硬化浆体结构趋于优化,更致密.     

牛奶纤维拉伸性能建模的研究

对牛奶纤维的力学性能进行了测试,利用四元件非线性粘弹模型对其应力应变关系进行了分析和模拟计算。结果表明:理论和实测结果符合得很好,该模型可用于预测牛奶纤维的拉伸性能。     

玄武岩纤维对混凝土扰动条件下力学性能的影响

为了解混凝土在持续扰动条件下力学性能变化规律,采用电磁振动台模拟正常交通状态下行车激发的桥梁振动,对桥梁修补用混凝土进行扰动,考察玄武岩纤维对混凝土抗扰动能力的影响.实验结果表明:扰动能明显降低混凝土抗压强度,加入玄武岩纤维以后,改善了混凝土因扰动导致的分层离析现象,明显提高了混凝土的抗扰动能力;L20纤维对提高混凝土的抗扰动能力优于L3纤维;扰动条件下,若掺加单一类型纤维,当L20纤维掺量为0.3％时混凝土抗压强度最大,若掺加混合纤维,当L20纤维掺量为0.1％,L3纤维掺量为0.2％时混凝土抗压强度最大;L20纤维掺量0.3％时,或者L20纤维掺量0.1％,L3纤维掺量0.1％时混凝土的抗扰动能力优秀.     

液体石蜡与凹凸棒土对聚丙烯力学性能影响的研究

以液体石蜡与凹凸棒土加入到聚丙烯并对力学性能的影响进行研究。将凹土与液体石蜡和聚丙烯在高速混合机中进行混合,再在挤出机中熔融挤出,注塑成型,研究液体石蜡与凹凸棒土对聚丙烯力学性能的影响。研究结果表明：液体石蜡和经硅烷偶联剂处理过的凹土能比较显著的提高PP的综合力学性能,当PP的用量为100份,凹土的用量为20份,LP为10份时拉伸强度及硬度性能最好。此时,拉伸强度为34.63 MPa,硬度为63.30。当PP的用量为100份,凹土的用量为20份,LP为20份时冲击强度最好,为11.11 kJ/m^2。     

凝固浴浓度对离子液体法纤维素纤维结构以及性能的影响

探讨了以离子液体1-丁基-3-甲基咪唑氯盐([BMIM]Cl)为溶剂制备的纤维素纤维纺丝工艺条件中凝固浴浓度对纤维结晶结构以及力学性能的影响。实验表明:在相同拉伸比和气隙条件下,凝固浴浓度对再生纤维素纤维的结构以及性能影响较大。随着凝固浴浓度的增加,纤维的结晶度和无定形取向都呈现先增大后减小的趋势,纤维的横向晶粒变小,拉伸强度、初始模量也呈先增大后减小的趋势。