光固化聚苯胺-环氧丙烯酸树脂互穿网络导电膜力学性能的研究

用原位乳液聚合法在环氧丙烯酸树脂(EA)中合成出了十二烷基苯磺酸掺杂的聚苯胺(PNAI-DBSA)与EA的混合物,脱水干燥后加入交联单体、引发剂2,4,6-二苯基氧化膦(TPO)等,混合均匀后用紫外光固化形成PNAI-DBSA/EA互穿网络导电膜。通过力学性能测定,研究了PANI-DBSA粒子含量、交联单体种类及用量等对导电膜力学性能的影响。结果表明:PANI-DBSA的含量和交联单体的种类及用量对导电膜的力学性能有明显影响,在PANI-DBSA、TPO、交联单体分别为体系总质量的15%、4%和50%时,固化40 s,乙氧基化三羟甲基丙烷三丙烯酸酯(EO-TMPTA)导电膜的拉伸强度最大,达15.24 MPa;丙烯酸羟乙酯(HEA)导电膜的断裂伸长率最大,达到24.8%。利用透射电镜和红外光谱分析分别对PANI-DBSA和导电膜进行了分析和表征。     

聚氨酯/镀银纳米石墨导电胶的制备与性能研究

以聚氨酯(PU)预聚体为基体,以镀银纳米石墨为导电填料,采用共混法制备PU/镀银纳米石墨导电胶,并与PU/纳米石墨导电胶进行电学性能、力学性能和热稳定性能对比。结果表明:PU/镀银纳米石墨导电胶和PU/纳米石墨导电胶的导电渗流阈值分别为3%和9%,此时对应的电导率分别为0.044 S/cm和0.012 S/cm;前者的力学性能(最大剪切强度为5.76 MPa)高于后者(最大剪切强度为3.65 MPa),并且前者的起始分解温度比后者提高了近10℃,说明前者的应用前景比后者更广阔。     

纳米纤维/氧化淀粉/PVA复合膜制备及特性

以甘蔗渣为原料,采用硫酸水解法制备甘蔗渣纳米纤维素。以氧化淀粉(OS)和聚乙烯醇(PVA)为基材,添加甘蔗渣纳米纤维素、增塑剂甘油、交联剂乙二醛制备复合膜。以拉伸强度、断裂伸长率、水蒸气透过率和水溶率为测量指标,研究了甘油、乙二醛、纳米纤维添加量对膜特性的影响。结果表明,随着甘油含量增大,复合膜的水溶率和水蒸气透过率逐渐增大,拉伸强度逐渐降低;添加乙二醛能够提高复合膜的耐水性能,添加量为0. 15 m L/g时,拉伸强度达到最大值(6. 25±0. 16) MPa;适当添加甘蔗渣纳米纤维素增强复合膜的机械性能和耐水性能,当纳米纤维含量为20%时,复合膜的水蒸气透过率达到最小值,为(5. 349±0. 056)×10~(-7)g/(m·h·Pa)。     

化学交联PE-LD/SBS共混物的形状记忆效应研究

分别用3种不同苯乙烯含量的苯乙烯-丁二烯共聚物(SBS)与低密度聚乙烯(PE-LD)混合制成共混物,采用过氧化苯甲酰(BPO)为引发剂,使共混物发生化学交联形成网状结构,对交联共混物的交联度进行了分析,测试了交联共混物的拉伸强度与断裂伸长率,探讨了交联共混物的形状记忆效应。结果表明,在PE-LD/SBS共混物中,随着BPO含量的增加,共混物的交联度增大;BPO含量固定时,随着SBS中丁二烯含量的增大共混物的交联度增大;随着交联度的增加,共混物的拉伸强度与断裂伸长率均下降;当BPO含量为0.5 %～1.5 %时,交联共混物具有良好的形状记忆效应。     

复合酸掺杂PVA/PANI/Ag复合膜的电化学制备及性能研究

采用电化学法制备了硫酸(H2SO4)和磺基水杨酸(SSA)共掺杂的导电聚乙烯醇/聚苯胺(PVA/PANI)复合膜,采用正交设计法优化了工艺条件,研究了沉积银电流密度和时间、拉伸对复合膜电导率的影响。采用红外光谱、X射线衍射、扫描电镜对复合膜进行表征。结果表明,最佳条件下获得的PVA/PANI复合膜的电导率为22.72 S/cm;在此复合膜上以50 mA/cm2沉积2 min银可使复合膜的电导率提高到1250 S/cm;对2种复合膜进行适当的拉伸可使其电导率分别提高20.74 %和18.04 %。复合膜有一定程度的结晶,经拉伸后其结晶度有所提高。     

导电炭黑/氯化丁基橡胶力学和电性能的研究

通过共混法制备了导电炭黑/氯化丁基橡胶复合材料,研究了复合材料的拉伸性能与导电、介电性能。研究发现,随着导电炭黑和硫化剂含量的增加,拉伸强度先出现一个极大值随后下降,在炭黑用量为5%,硫化剂用量为3%时,拉伸强度最大,为9.1 MPa;而断裂伸长率一直下降。当导电炭黑超过5%以后,电导率迅速增加,出现渗流现象。介电常数实部ε′和介电损耗因子tanδ随导电炭黑用量的增加而增大,但当导电炭黑用量较高(20%)时,在高频时,ε′和tanδ都下降。     

还原纳米石墨/聚氨酯导电胶的制备与性能研究

利用异氰酸酯与多元醇在不同的反应条件下制取三种性能不同的聚氨酯(PU)预聚体(PUⅠ、PUⅡ和PUⅢ),然后分别与还原纳米石墨(RNG)、三羟甲基丙烷(TMP)混合制备三种RNG/PU导电胶(RNG/PUⅠ、RNG/PUⅡ和RNG/PUⅢ)。运用多种检测手段对导电胶的导电性能、力学性能和热稳定性能进行了分析。结果表明:随着RNG质量分数的增加,三种导电胶的导电性能均增强,其导电逾渗阀值分别为10.0%、16.7%和20.0%;导电胶的拉伸剪切强度随RNG质量分数的增加呈先升后降的趋势,当w(RNG)=20%时导电胶的拉伸剪切强度为1.37～4.40MPa;RNG的加入使导电胶的热稳定性能明显提高。     

交联PVA/SiO_2复合膜的制备及性能

采用一种氮丙啶交联剂对聚乙烯醇(PVA)进行交联,通过红外等测试表征研究交联剂用量对交联膜化学结构、力学性能、溶胀性及耐水性的影响,从而确定薄膜性能最优时交联剂的用量.当交联剂用量质量分数为3%时,其拉伸强度和断裂伸长率分别提高25.9%和38.1%,力学性能得到明显改善.将性能最优交联膜与纳米SiO_2复合,测试复合膜的力学性能,结果表明:其性能得到进一步提高.     

聚氨酯/纳米金刚石纳米复合材料的性能研究

通过原位反应法制备了聚氨酯(PU)/纳米金刚石(ND)纳米复合材料,采用X射线衍射(XRD)、热失重分析(TGA)、扫描电子显微镜(SEM)和力学性能测试等手段系统研究了PU/ND纳米复合材料的力学性能、热性能和形态。研究结果表明,ND能够显著提高聚氨酯的力学性能。随着ND用量的增加,PU/ND纳米复合材料的拉伸强度、100%定伸应力、500%定伸应力和断裂伸长率先增加后减少。当ND质量分数为0.5%时,PU/ND纳米复合材料的力学性能最佳,拉伸强度和断裂伸长率分别提高了61.5%和39.1%。PU/ND纳米复合材料的T-剥离强度和耐热性也有提高。     

形状记忆剑麻微晶/聚氨酯复合材料的制备与性能（英文）

用剑麻微晶(MCFs)作为交联剂制备了交联型形状记忆聚氨酯(PU)复合材料,考察了MCFs含量不同的MCFs/PU复合材料的力学性能及形状记忆性能。结果表明,MCFs/PU复合材料的力学性能随MCFs含量的增加而明显提升。在MCFs质量分数为0.75%时复合材料具备最佳的力学性能,拉伸强度和扯断伸长率比纯PU可分别提高约80%和500%;同时可赋予MCFs/PU复合材料暂时形变并加热诱导其形状记忆,形状回复率最高可达96%,形状记忆性能优异。     

TIPA/BDO扩链的聚氨酯弹性体力学性能的研究

以聚酯(PEA、PEPA)或聚醚(PTMG)和TDI为原料合成聚氨酯(PU)预聚体,用三异丙醇胺(TIPA)和1,4-丁二醇(BDO)的混合物作扩链剂制备PU弹性体。讨论了软段相对分子质量、弹性体交联点相对分子质量和扩链剂的种类对PU弹性体性能的影响。结果表明,PU弹性体的硬度、拉伸强度、300%模量和撕裂强度随软段相对分子质量的增加而下降,而伸长率和冲击弹性随软段相对分子质量的增加而增加;交联点相对分子质量为6600时,PTMG2000为软段的PU弹性体的拉伸强度最高,达到28.44MPa;与TMP/BDO扩链的聚酯型PU弹性体相比,TIPA/BDO扩链的弹性体的拉伸强度、伸长率和撕裂强度均较高,而硬度、300%模量和冲击弹性差异不大。     

Electrochemical preparation of electrically conducting polyurethane/polyaniline composite

Composite films from polyaniline (PANi) and polyurethane (PU), with flexibility and mechanical strength similar to pure PU and conductivity close to pure PANi, have been obtained by electropolymerizing amiline on a PU/Pt electrode in water/acetonitrile/ethylen glycol electrolyte solution. In the composite films, PANi is dispersed, in the form of particulate, inside and on the inner surface of the PU substrates. It is found that the electropolymerization reaction of aniline proceeds much faster in basic solution and composite film as prepared shows higher conductivity than that in acidic solution. PANi in PU/PANi composite film is protonic-acid-doped and is conducting even in case it is electropolymerized in a basic electrolyte solution.     

Studies on physico‐mechanical and optical properties,and WAXS of castor oil based polyurethane/polyacrylates interpenetrating polymer networks

Interpenetrating polymer networks (IPNs) of polyurethane (PU)/polyacrylates have been synthesized by sequential polymerization of castor oil, methylene diisocyanate (MDI), and acrylate monomers such as methyl acrylate (MA), methyl methacrylate (MMA), and ethyl acrylate (EA); with benzoyl peroxide (BPO) and ethylene glycol dimethyl acrylate (EGDM) as an initiator and crosslinker, respectively. The physico‐mechanical properties, such as density, surface hardness, tensile strength, percentage elongation at break, and tear strength; and the optical properties, like total transmittance and haze, of PU/polyacrylate IPNs have been reported. Microcrystalline parameters of IPNs have been computed by using wide angle X‐ray scattering (WAXS) recordings. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 764–773, 2005     

TDI/BPO改性PBS的力学性能研究

本文采用扩链手段和交联手段对PBS进行改性研究。分别选用甲苯2,4-二异氰酸酯(TDI)为扩链剂,过氧化苯甲酰(BPO)为交联剂。使用乌氏黏度计、索氏抽提器对改性体系的特性黏数和交联度进行测定;使用哈克转矩流变仪、毛细管流变仪、差示扫描量热仪、万能拉力测试机等手段测试了改性体系的加工性能,流变性能,结晶与热性能,以及力学性能等。研究了扩链剂和交联剂用量对改性体系性能的影响。结果表明,随着TDI用量的增加,PBS改性体系的特性黏数逐渐增大,加工体系的平衡扭矩提高,熔体黏度呈现出增大的趋势,从而熔体强度增大。通过扩链反应,结晶温度提高,结晶度降低,熔点升高,拉伸强度变化不大,当TDI用量为1.0%时,拉伸强度最大。随着BPO用量的增加,PBS改性体系的交联度逐渐增大,加工性能得到改善,熔体黏度大幅提高,从而熔体强度增大。交联度的增大使得改性体系的结晶温度提高,结晶度和熔点均降低,拉伸强度呈现出先增大后减小的趋势。     

水性聚氨酯／丙烯酸酯复合细乳液的研究

用细乳液聚合的方法制备水性聚氨酯／丙烯酸酯复合细乳液,研究了引发剂的种类与用量对乳液的影响,并对胶膜进行热重分析,同时根据实验标准测试胶膜的拉伸强度和剥离强度。实验表明：PU加入量为15％时,胶膜拉伸强度提高23％,此处的断裂伸长率和剥离强度也达到了最大值。     

Metal–organic framework (UiO‐66)‐dispersed polyurethane composite films for the decontamination of methyl paraoxon

Polyurethane (PU) composite films containing UiO‐66 were prepared for the decontamination of methyl paraoxon (MPO), an organophosphate‐type nerve agent simulant. Waterborne PU dispersions were synthesized by changing the type of polyol to improve the miscibility with UiO‐66. Depending on the size of the polyol, the PU films had different surface free energy, flexibility and compatibility with UiO‐66. UiO‐66 was well dispersed in PU films when the flexibility of the films increased. The tensile strength of the UiO‐66/PU composite films gradually increased from 7.5 to 11.3 MPa with increasing UiO‐66 content, but the elongation decreased from 781 to 120%. The decomposition of MPO by the UiO‐66/PU composite films increased with an increase of the UiO‐66 content and hydrolysis time. In the case of the 21.2 wt% UiO‐66/PU composite film, 48% of MPO was decomposed within 3 h. This was similar to the decomposition when using a UiO‐66 slurry (52%) under the same decomposition conditions. Unlike the UiO‐66 slurry, the 21.2 wt% UiO‐66/PU composite film maintained a similar MPO decomposition performance after 10 repeated experiments. © 2019 Society of Chemical Industry     

Effect of polymer architecture and hard/soft segment ratio on the surface morphology and mechanical properties of polyurethane films for potential orthodontic treatment

In this study, polyurethane (PU) films are prepared by using 1,4-butanediol and trimethylolpropane as chain extender and crosslinking agent, respectively. A series of prepolymers are synthesized by varying the feeding molar ratios of methylene diisocyanate to polytetramethylene ether glycol, which are hard and soft segments, respectively. The influence of polymer architecture, chemical composition, and artificial saliva treatment on the surface morphology and mechanical strength of PU films are studied. The crosslinking polymer architecture and higher content of hard segment correlates with enhanced tensile strength and less decrease of tensile strength in the condition of artificial saliva, but reduced elongation at break. The in vitro cytotoxicity study demonstrates that PU films have excellent cytocompatibility.     

合成革用水性聚氨酯的制备

以异佛尔酮二异氰酸酯( IPDI),聚酯或聚醚多元醇、二羟甲基丙酸(DMPA)为主要原料,采用预聚体法合成了脂肪族革用水性聚氨酯(WPU),用三甲氧基三聚氰胺树脂(TMMM)对WPU进行交联反应成膜,考察了nNCO/nOH,DMPA用量、聚酯或聚醚种类以及TMMM对WPU性能的影响.结果表明,随着nNCO/nOH的增加...     

Enhanced adhesion force based on microphase separation induced by complexation of ferric ions and polyurethane matrix

Waterborne polyurethane elastomer (WPU) has been widely used as a glue, but it still has some drawbacks, including a long cure time and weak adhesive force. In order to overcome these drawbacks, a new composite [PU/ferric ion complexation (Fe/PU)] with high adhesive strength was successfully prepared using ferric ion (Fe³⁺) as a complexing agent. Fourier transform infrared spectroscopy, differential scanning calorimetry, dynamic mechanical analysis, and tensile testing were used to characterize the chemical structure and mechanical properties of the as‐obtained composites. Introduction of the ferric ion induces a certain degree of microphase separation, resulting in better mechanical strength and interfacial adhesion. The mechanical properties of the PU composite with ferric ions are higher than that of pure PU. The adhesive strength of the 25%‐Fe/PU composite is 32.46 ± 3.1 MPa, exhibiting superior adhesive strength. The tensile strength was enhanced 34%, and the elongation was enhanced 23.6% compared to pure PU. Furthermore, the Fe/PU composite, coordinated with ferric ions, exhibits an enhanced storage modulus and reduced loss coefficient compared to PU. We can foresee that Fe/PU composites will play an important role in the building and engineering areas. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46069.     

Graft copolymerization of acrylic acid on to styrene butadiene rubber (SBR) to improve morphology and mechanical properties of SBR/polyurethane blend

Graft copolymerization of acrylic acid (AA) on to styrene butadiene rubber (SBR) is carried out via free radical polymerization using benzoyl peroxide (BPO) as initiator. Graft yield (GY) and graft efficiency (GE) measurements reveal that the optimum grafting is achieved when 100 wt % of AA and 3 wt % of BPO are used for a reaction time of 6 h at 60 °C. The execution of the grafting process is confirmed through ATR‐IR spectroscopy and DMTA analysis. Tan δ thermograms indicate that the graft copolymerization occurs in the styrene segments of the SBR backbone. An in situ polymerized, semicrystalline polyurethane (PU) is then used to prepare a series of SBR‐g‐PAA/PU blends. It is found that the SBR‐g‐PAA with the highest GY exhibits the best compatibility with PU matrix. One‐phase morphology (SEM), as well as the appearance of only one glass transition (DMTA) verify the homogeneous miscibility of the modified blend compositions. Moreover, the integration of PUs crystalline structure into blends gives rise to elongation‐induced crystallinity as the prominent phenomenon in tensile testing, which proves to synchronously enhance tensile strength, modulus, elongation at break, and toughness. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43699.