互穿网络高吸水树脂IPN的合成

采用溶液聚合制备了聚乙烯醇(PVA)和部分中和的丙烯酸-丙烯酰胺共聚物复合的互穿网络高吸水树脂(IPN)。通过正交实验研究了单体浓度,交联剂用量对IPN吸水率的影响。PVA的加入能有效提高IPN的吸水能力。在较适宜的反应条件下,IPN吸蒸馏水量达1481倍,吸0.9%NaCl溶液为130倍。     

端羟基聚丁二烯型聚氨酯/聚苯乙烯(或聚甲基丙烯酸甲酯)互穿网络的形态和玻璃化转变

互穿聚合物网络(IPN'S)已经成为高聚物共混改性,高聚物间相容性的一个重要研究领域,IPN材料的宏观性能与其微观形态有着密切的关系,如能通过改变结构、组成、交联密度及合成条件等因素来控制IPN的形态,则就可以入为地制备各种性能优良的材料。本文用透射电镜和差示扫描量热仪对同步法合成的端羟基聚丁二烯型聚氨     

含氢键相互作用的IPN体系(Ⅴ)——体系组成变化对相结构和性能的影响

研究了含引入氢键的PBA和PS(OH)组成的IPN体系,PS(OH)为含羟基的改性聚苯乙烯.与相应的非交联聚合物的共混体系不同,IPN均显示两相结构,一相几乎为纯PBA,另一相则是混合相;仅当PS(OH)中羟基含量高达30mol％且其为IPN的主要成分时,才有相当量的PS(OH)溶入PBA为主的相.IPN的模量-组成行为可用Budiansky方程描述,表明两相的连续性,这一结论与透射电子显微镜的观察一致.     

负载蛋白质的胶原/聚两性电解质IPN角膜替代物

以碳二亚胺/N-羟基琥珀酰亚胺(EDC/NHS)和聚乙二醇二丙烯酸酯(PEGDA)为交联剂分别对猪皮去端肽Ⅰ型胶原和3-(甲基丙烯酰胺)丙基-二甲基(3-磺丙)胺(MPDSAH)进行交联, 制备了具有互穿聚合物网络(IPN)结构的角膜替代物. 胶原基IPN角膜替代物的折光指数和白光透过率与天然人角膜相似. IPN水凝胶具有优于纯胶原凝胶的力学性能, 同时PMPDSAH网络的引入明显提高了IPN凝胶在胶原酶中的稳定性. 体外细胞培养实验结果表明, IPN角膜替代物支持人角膜上皮细胞生长. 通过冷冻干燥-溶胀后包覆技术可将牛血清白蛋白(BSA)和神经生长因子(NGF)装载到角膜替代物中, 负载药物的冻干凝胶可干态保存, 避免了湿态下蛋白质等活性因子的失活和漏泄; 再吸水恢复原状的特性可使角膜替代物完好地移植病灶部位, NGF具有良好的缓释效果. 此负载NGF的复合角膜替代物有望促进角膜组织和神经的再生.     

瓜胶/聚丙烯酸互穿聚合物网络水凝胶对模型药物的负载与控制释放

考察了以牛乳清蛋白(BSA)为模型药物,通过相平衡分配法制备载药瓜胶(GG)/聚丙烯酸(PAA)互穿聚合物网络(IPN)水凝胶的工艺条件.借助紫外可见光谱仪研究了载药水凝胶在结肠酶存在下的控制释放行为.结果表明:载药容量(CM)随瓜胶、丙烯酸用量的增加而下降,半IPN水凝胶的Cm较全IPN的略大;结肠酶能明显提高半IPN与全IPN中的BSA释放速率,且提高幅度随GG含量的增加而加快,GG/PAA IPN水凝胶具有结肠定位降解的特性,有望成为靶向结肠给药的理想载体材料.     

丙烯酸酯改性水性聚氨酯乳液的制备及性能研究

采用共聚的方法制备出丙烯酸酯改性的水性聚氨酯共聚乳液(PUA乳液),并对PUA乳液的制备方法和工艺、耐溶剂性、机械稳定性进行了初步的研究。结果表明,具有IPN结构的PUA乳液耐溶剂性、机械稳定性比水性PU有明显的提高。     

快速pH响应丝胶/聚甲基丙烯酸互穿网络水凝胶的合成及表征

采用同步互穿网络方法制备丝胶蛋白(SS)/聚甲基丙烯酸(PMAA)为组分的互穿网络(IPN)水凝胶. 研究了互穿网络水凝胶对介质pH的刺激响应性能. 结果表明, IPN水凝胶具有强烈的pH刺激响应性能. 在pH=9.2的缓冲溶液中, -COOH解离成 -COO^-, 渗透压与网络之间的静电排斥作用导致IPN的溶胀度增大; 当pH减小时, 溶胀度随之减小. IPN水凝胶具有快速退溶胀速率及可逆溶胀-收缩性能.     

改性Raney Ni催化剂用于加氢合成间苯二甲胺

采用改性RaneyNi催化剂,研究了溶剂、温度、压力、催化剂用量对间苯二甲腈(IPN)加氢合成间苯二甲胺(m-XDA)反应的影响.结果表明,该催化剂在以甲醇、甲苯为混合溶剂,V(甲醇)∶V(甲苯)=1∶2,当m(溶剂)∶m(IPN)=3∶1,反应温度70℃、压力6.0MPa～7.0MPa、催化剂用量为原料质量的10%时,IPN转化率接近100%,m-XDA收率达97%.失活催化剂经再生,即能恢复其性能.     

疏水/亲水性大孔聚二乙烯基苯/聚丙烯酰乙二胺互贯网络的合成及对水溶液中双酚A的吸附研究

采用分步悬浮聚合法制备了由大孔聚二乙烯基苯和聚丙烯酸甲酯组成的聚合物互贯网络(Interpenetrating polymer networks IPN),经过乙二胺氨解,得到由疏水性的大孔聚二乙烯基苯和亲水性的聚丙烯酰乙二胺组成的聚合物互贯网络(polydivinylbenzene/polyacrylethylenediamine IPN即PDVB/PAEM IPN),测定了合成的IPN的物理和化学结构,研究了PDVB/PAEM IPN对pH 6.5的水溶液中双酚A (Bisphenol A即BPA)的吸附性能.结果表明,合成的PDVB/PAEM IPN是含有氨基和酰胺基的多孔性IPN;树脂对水溶液申双酚A的等量吸附焓在20kJ/mol～50kJ/mol之间;动态吸附及脱附实验表明,湿态PDVB/PAEM IPN树脂对水溶液中双酚A的饱和吸附量达到约30mg/mL.树脂可以通过乙醇再生.     

疏水/亲水大孔聚二乙烯基苯/聚(N-2-氨基乙基丙烯酰胺)IPN树脂的合成及对水杨酸吸附性能研究

采用分步悬浮聚合法制备了聚二乙烯基苯/聚丙烯酸甲酯(PDVB/PMA)大孔互穿聚合物网络,将其中的聚丙烯酸甲酯用乙二胺氨解,合成了具有疏水/亲水性能的聚二乙烯基苯/聚(N-2-氨基乙基丙烯酰胺)(PDVB/PNAEAM)大孔互穿聚合物网络(IPN);测定了该树脂的孔结构、含水量、弱碱交换量和溶胀性能;测定了该树脂对水杨酸在不同温度下的吸附等温线,利用热力学函数关系计算出了吸附焓、自由能和熵.推测PDVB/PNAEAM IPN树脂中疏水性的PDVB一网具有疏水作用吸附能力、亲水性的PNAEAM一网具有氢键作用吸附能力.动态吸附及脱附实验表明湿态PDVB/PNAEAM IPN树脂对水溶液中水杨酸的饱和吸附量达到46.1mg/mL.树脂可以通过4%NaOH溶液再生.PDVB/PNAEAM IPN树脂在分离工业废水中水杨酸等芳香有机酸有良好的应用前景.     

Natural and acid-treated attapulgite reinforced soybean oil-based polyurethane/epoxy resin interpenetrating polymer networks

Soybean oil-based polyurethane (PU)/epoxy (EP) interpenetrating polymer network (IPN) nanocomposites were prepared with natural attapulgite (N-ATT) and acid-treated attapulgite (A-ATT). The structure, glass transition, damping properties, thermal stability, mechanical properties and morphology of PU/EP IPN/ATT nanocomposites were characterized by X-ray diffraction (XRD), dynamic mechanical analysis (DMA), thermogravimetric analyzer, universal test machine and scanning electronic microscope (SEM). XRD showed that interaction with PU did not change the crystal structures of ATT. DMA results revealed the addition of ATT improved the glass transition temperature of the soybean oil-based PU/EP IPN, especially for A-ATT. However, the incorporation of ATT slightly decreased the damping properties of the soybean oil-based PU/EP IPN. Tensile tests confirmed that A-ATT had a significant reinforcement effect on the soybean oil-based PU/EP IPN. The tensile strength of the soybean oil-based PU/EP IPN increased by 56% with the addition of 4 mass% A-ATT. SEM demonstrated the relatively uniform dispersion of both N-ATT and A-ATT in the soybean oil-based PU/EP IPN matrix.

     

Interpenetrating polymer networks from polyurethanes and methacrylate polymers. I. Effect of molecular weight of polyols and NCO/OH ratio of urethane prepolymers on properties and morphology of IPNs

Two types of reinforced elastomeric interpentrating polymer network (IPN) were prepared by simultaneous polymerization and crosslinking in solution. The first type consisted of polyurethane-poly(methyl methacrylate) (PU/PMMA), and the second, of polyurethane-poly(methyl methacrylate-methacrylic acid) PU/P(MMA–MAA) of constant composition (90/10) and (80/20) by weight, respectively. The members of each type differed in the NCO/OH ratio of the PU prepolymer and the molecular weight (MW) of the polyol in the PU component because we wished to investigate systematically the effect of changing the NCO/OH ratio and MW of the polyol on the mechanical properties and morphology of the resulting IPNs. The mechanical properties, particularly the modulus of both tyes of IPN, increased with increasing NCO/OH ratio and decreased with increasing MW of the polyol in the PU. The morphology of the IPNs was studied by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). Improved phase compatibility and decreasing extent of phase separation was observed in both types of IPN with increasing NCO/OH ratio and decreasing MW of the polyol used in the PU. These results may imply that improved interpenetration results from increasing the NCO/OH ratio and decreasing the MW of the polyol in the PU component. The fact that the effect is more pronounced with the type of PU-P(MMA–MAA) IPN can be rationalized as due to the additional hydrogen bonding between the carbonyl in the carboxyl groups and the urethane or urea groups in the PU component.     

聚醚聚氨酯/环氧树脂互穿网络聚合物的研究(Ⅱ)

合成了不同类型聚醚聚氨酯/环氧树脂(PU/EP)互穿网络聚合物(IPN),通过改变PU中聚乙二醇分子量、3OH/2OH及NCO/OH比值等,研究IPN组份间分子混合程度,采用电镜、动态力学分析及应力应变等测试方法表征。结果表明:聚乙二醇分子量降低及3OH/2OH、NCO/OH比的提高,可使相容性提高,材料力学性能增强。     

Room temperature synthesis and mechanical properties of two kinds of elastomeric interpenetrating polymer networks based on castor oil

Two kinds of interpenetrating polymer networks (IPNs) composed of two-component polyurethane (PU) and vinyl or methacrylic polymer (PV), namely, (polyether-castor oil)PU/PV IPN(I) and (polybutadiene-castor oil)PU/PV IPN(II), were synthesized at room temperature using benzoyl peroxide and N,N-dimethylaniline as redox initiator and dibutyltin dilaurate as catalyst. The former IPN was prepared by polymerization of castor oil, NCO-terminated polyether and vinyl or methacrylic monomer together and the latter IPN was obtained by polymerization of castor oil, NCO-terminated polybutadiene, NCO-terminated castor oil and vinyl or methacrylic monomer together. Various synthesis conditions affecting mechanical properties of the two kinds of IPNs were studied. Acrylonitrile (AN) is a good monomer for synthesizing IPN(I), but is a poor monomer for preparing IPN(II). At optimum conditions for the synthesis, both the (polyether-castor oil)PU/PAN IPNs and the (polybutadiene-castor oil)PU/polystyrene (PSt) IPNs possess permanent set about 10%, tensile strength over 13 and 11 MPa and ultimate elongation over 240% and 270%, respectively, thus behaving as elastomers. TEM micrograph of a (polybutadiene-castor oil)PU/PSt IPN showed a microphase separation in the IPN.     

聚氨酯/聚苯乙烯互穿聚合物网络的研究

互穿聚合物网络形态和力学性能的研究已有报道^[1～3],但有关合成过程中分子量变化形态和性能的影响研究甚少。本文在动力学研究的基础上^[4],用GPC、DSC和Instron万能机研究了聚氨酯/聚苯乙烯互穿聚合物网络(PU/PSt-IPN)的分子量,玻璃化转变温度和力能,考察了分子量与相分离点之间的关系。     

Synthesis and characterization of polyaniline filled PU/PMMA interpenetrating polymer networks

A series of conducting interpenetrating polymer networks (IPNs), are prepared by sequential polymerization of castor oil based polyurethane (PU) with poly(methyl methacrylate) (PMMA) and polyaniline doped with camphor sulphonic acid (PAni)_CSA. The effect of different amount of PAni (varies from 2.5-12.5%) on the properties of PU/PMMA (50/50) IPNs such as electrical properties like conductivity, dielectric constant and dissipation factor; mechanical properties like tensile strength and percentage elongation at break have been reported. (PAni)_CSA filled IPNs shows improved tensile strength than the unfilled IPN system. The thermal stability and surface morphology of unfilled and (PAni)_CSA filled PU/PMMA (50/50) IPN sheets were investigated using a thermogravimetric analyzer (TGA) and a scanning electron microscope (SEM). TGA thermograms of (PAni)_CSA filled PU/PMMA (50/50) IPNs show a three-step thermal degradation process. SEM micrograms of filled PU/PMMA IPN system shows spherulitic structure at higher concentration of (PAni)_CSA.     

Interpenetrating polymer network from castor oil-based polyurethanes and poly(methyl methacrylate). XV

The polyurethanes have been prepared from 2.12 functional ? OH containing castor oil and diphenyl methane diisocyanate under identical experimental conditions with a varying NCO/OH ratio. These polyurethanes were swollen in methyl methacrylate and subsequently interpenetrated by free radical polymerization using benzoyl peroxide and crosslinker ethylene glycol dimethacrylate. A series of interpenetrating polymer network (IPN) PU/PMMA IPNs were obtained as films by a transfer moulding technique. These IPNs were characterized by their resistance to chemical reagents, thermal behavior, and mechanical properties. The morphology was shown by SEM and dielectric properties at different temperatures were measured.     

Miscibility and properties of polyurethane/benzyl starch semi‐interpenetrating polymer networks

We successfully prepared a series of transparent materials with semi‐interpenetrating polymer networks (semi‐IPNs) from castor‐oil‐based polyurethane (PU) and benzyl starch (BS). The miscibility, morphology, and properties of the semi‐IPN films were investigated with attenuated total reflection/Fourier transform infrared spectroscopy, differential scanning calorimetry, dynamic mechanical thermal analysis, scanning electron microscopy, wide‐angle X‐ray diffraction, electron spin resonance (ESR), ultraviolet–visible spectroscopy, and tensile testing. The results revealed that the semi‐IPN films had good or certain miscibility with BS concentrations of 5–70 wt % because of the strong intermolecular interactions between PU and BS. With an increase in the concentration of BS, the tensile strength and Young's modulus of the semi‐IPN materials increased. The ESR data confirmed that the segment volume of PU in the semi‐IPNs increased with the addition of BS; that is, the chain stiffness increased as a result of strong interactions between PU and BS macromolecules. It was concluded that starch derivatives containing benzyl groups in the side chains more easily penetrated the PU networks to form semi‐IPNs than those containing aliphatic groups, and this led to improved properties. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 603–615, 2005     

聚氨酯/环氧树脂互穿网络硬质泡沫塑料反应过程和微观结构

聚氨酯／环氧树脂互穿网络(PU／EPIPN)硬泡中异氰酸根的消耗速度较纯PU硬泡高，是由于环氧树脂的固化荆同时也是异氰酸根反应的催化荆。而PU／EP IPN硬泡中环氧基的反应速度和反应程度均较纯EP网络低，归因于互穿网络对基团扩散的阻碍。在互穿网络硬泡形成过程中，存在环氧开环中所新产生的羟基与异氰酸根的反应、大分子多元醇中羟基与环氧基的反应以及异氰酸根与环氧基形成嗯唑烷酮的反应三种形成网络间的化学键的途径。同时由于PU／EPIPN硬泡高度的交联，使得IPN硬泡中两个网络具有良好的相容性。动态力学性能表明所有IPN样品都只有一个玻璃化温度。透射电镜表明IPN样品无明显的相界面。     

Semi‐interpenetrating polymer networks based on polyurethane and polymethacrylate functional prepolymers: Morphology and mechanical properties in dependence of the concentration of functional groups

Grafted semi‐interpenetrating polymer networks (IPNs) were prepared from polyurethane (PU) prepolymers with polyester soft segments and hard segments containing carboxylic functional groups as well as polymethacrylate (PM) prepolymers with tertiary amine functional groups. The dependence of morphological and mechanical properties on the concentration of functional groups was studied. The enhanced miscibility of PU and PM prepolymers was observed at concentrations of functional groups of 0.25 mmol/g of polymer and above. Despite the improved miscibility, the PM prepolymers showed a tendency toward phase separation. Because the observed glass‐transition temperature shifts of PU prepolymers indicated substantial miscibility, we ascribed this phenomenon to the presence of methyl methacrylate rich sequences in the PM prepolymer. The observed changes in mechanical properties by increasing the content of functional groups were typical for ionomers. Young's modulus increased as a result of physical interactions between functional groups. A significant drop in tensile strength was observed in IPN samples with phase‐separated PU and PM prepolymers. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 40: 115–123, 2002