氯磺化聚乙烯/聚甲基丙烯酸丁酯/环氧树脂三组分IPNs的合成与表征

采用同步-分步结合的方法合成了氯磺化聚乙烯/聚甲基丙烯酸丁酯/环氧树脂(CSM/PB-MA/EP)三组分IPNs.先用同步法合成CSM/EP二组分IPNs作为骨架网络,再将PBMA溶胀进入骨架网络中.得到三组分IPNs.网络间经两次相互缠结贯穿后,比单独用同步法或分步法合成的IPNs对网络间束缚作用大,且骨架网络与PBMA组成比较接近时,相容性较好.TEM结果表明:用分步染色方法可以观察三相间的形态变化和相区尺寸的相对大小.     

Mechanism of adhesion of polyurethane/polymethacrylate simultaneous interpenetrating networks adhesives to polymer substrates

Polyether-based polyurethane/poly (methyl methacrylate-co-ethyleneglycol dimethacrylate) interpenetrating polymer networks [PU/P (MMA–co–EGDMA)-IPNs] were synthesized and used as adhesives to adhere vulcanized natural rubber (NR) and soft polyvinyl chloride (PVC). The structure and morphology of the IPN adhesives in bulk and near the adhesive/substrate interfaces were investigated. A new mechanism of adhesion called conjugate interpenetration of networks across interfaces, which is suitable for IPN adhesives and polymer substrates, was put forward. According to this mechanism, while forming simultaneous interpenetrating networks in the adhesive, the monomers in the IPN adhesive can permeate polymer substrates and polymerize in situ to form gradient IPNs, thereby producing conjugate three-component IPNs near the adhesive/substrate interfaces. It is the conjugate interpenetration of the networks across the interfaces that strengthens interfacial combination remarkably and results in high bond strength of IPN adhesives. © 1994 John Wiley & Sons, Inc.     

聚氨酯/丙烯酸酯类树脂互穿网络的结构形态与力学性能研究——网络间化学键的影响

通过示差扫描量热计、扫描电镜与广角Ｘ 光衍射仪研究了由碳化二亚胺改性二苯基甲烷二异氰酸酯合成的聚氨酯（ＰＵ）与丙烯酸酯类树脂（ＶＥＲ）形成的同步互穿网络（ＳＩＮ）的结构、形态与力学性能,发现网络间的化学键对其影响极大．网络间没有化学键连接的ＰＵ／ＶＥＲＳＩＮｓ是一个热力学不相容体系,存在显著的相分离形态,后者同时与两个网络的形成速率与工程因素有关;对于网络间有化学键连接的ＰＵ／ＶＥＲＳＩＮｓ,两个网络间存在一定的相容性与互穿程度,故较显著地提高ＳＩＮ的力学性能．     

Physico-mechanical, thermal and morphological behaviour of polyurethane/poly(methyl methacrylate) semi-interpenetrating polymer networks

Semi-interpenetrating polymer networks (SIPNs) of polyurethane (PU) and poly(methyl methacrylate) (PMMA) in different weight ratios viz., 90/10, 70/30, 60/40 and 50/50 were prepared. The SIPNs were characterized for physico-mechanical properties like density, tensile strength and elongation at break. Thermal stability of IPNs was measured using thermogravimetric analysis (TGA). From the TGA thermograms it was noticed that all IPNs are stable up to 325 °C and undergo three-step thermal degradation in the temperature ranges 251-400, 378-508 and 445-645 °C for first, second and third steps, respectively. Thermal degradation kinetic parameters like activation energy (E_a) were calculated using Broido, Coats-Redfern and Horowitz-Metzger models. The values obtained by Broido and Horowitz-Metzger methods showed concurrency, whereas Coats-Redfern method showed relatively lower values. Surface morphology measured using scanning electron microscope (SEM) showed two-phase morphology for all the IPNs.     

Physico-mechanical and free volume behaviour of guar gum filled polyurethane/polyacrylonitrile biodegradable composites

A series of different weight ratios of guar gum viz. 5, 10, 20 and 30 were incorporated into polyurethane/polyacrylonitrile (PU/PAN, 50/50) semi interpenetrating polymer networks (SIPNs) using polyethylene glycol-400, 4,4′-diphenyl methane diisocyanate, acrylonitrile, benzoyl peroxide and new metallic catalyst. The obtained polymer composites were subjected to biodegradation studies using specific fungi Aspergillus niger. The composites are characterized for physico-mechanical properties like density and tensile behaviour of the specimens before and after biodegradation. The positron annihilation lifetime spectroscopy (PALS) was used to monitor the content of free volume before and after biodegradation. The extent of degradation was examined by change in tensile behaviour and surface morphology. The influences of fungi on mechanical and morphological behaviour of filled IPNs are found to be interesting. The free volume changes in the composite systems correlates well with the mechanical properties.     

聚醋酸乙烯酯/聚丙烯酸甲酯互穿网络聚合物的研究 Ⅴ.互穿缠结对相区结构的稳定作用

用定量的甲苯溶胀聚醋酸乙烯酯/聚丙烯酸甲酯互穿网络聚合物(PVAc/PMA IPN),使体系处于分相的热力学条件;或醇解其中的PVAc 网络,即增加两组份的化学不相容性.动态力学谱和透射电镜等结果表明,IPN 和网络Ⅰ的交联密度较高的半 IPN 试样,没有发生进一步的相分离,证明网络互穿缠结是永久性的物理缠结,并且有强迫互容作用的存在.     

Physico-mechanical and WAXS studies of PU/PS semi interpenetrating polymer networks

The polyethylene glycol (PEG) based polyurethane (PU) and its semi interpenetrating polymer networks (SIPNs) with polystyrene (PS) were prepared. The FTIR, physico-mechanical properties like density, tensile strength, percentage elongation at break and surface hardness of the IPNs were measured. Wide angle X-ray studies (WAXS) were made to know the microcrystalline parameters such as crystal size (〈N〉), lattice disorder (g), surface (D_s) and volume (D_v) weighted crystal size of SIPNs. The different asymmetric column length distribution functions were employed using Exponential, Lognormal and Reinhold methods and the results are compared.     

Synthesis and characterization of crosslinked polydiacetylene and its two-component interpenetrating polymer networks

The synthesis of crosslinked polydiacetylenes and its two-component interpenetrating polymer networks (IPNs) was carried out utilizing its polar and flexible substituent groups. Polydiacetylenes were crosslinked by the formation of allophanate linkages utilizing urethane groups in the substituent groups of the polydiacetylenes. Elemental analysis, DSC, TMA, solvent resistance, and IR spectra are presented as evidence for the formation of crosslinked polydiacetylenes. IPNs of polydiacetylenes and an epoxy resin (diglycidyl ether of bisphenol A) were synthesized by using simultaneous and sequential methods of synthesis. A study of phase morphology of the simultaneous and sequential IPNs was carried out using electron microscopy, TMA, and DSC.     

Poly (2,6-dimethyl-1,4-phenylene oxide)/poly (butadiene) diol interpenetrating polymer networks: Phase morphological characteristics and glass transition temperature behavior

The fracture surface topography of simultaneous interpenetrating polymer networks (SIN'S) of poly (2,6-dimethyl-1,4 phenylene oxide) (PPO)/poly (butadiene) diol was examined by scanning electron microscopy (SEM). The phase morphology of the IPNs is highly dependent on PPO/poly (butadiene) diol mass ratio. A single-phase morphology of the IPNs was achieved when the content of poly (butadiene) diol is below 40 wt % in the initial composition. The SEM observations are also wholly consistent with the glass transition temperature behavior obtained in the differential scanning calorimetric (DSC) measurements. © 1994 John Wiley & Sons, Inc.     

SYNTHESIS AND CHARACTERIZATION OF POLYDIMETHYLSILOXANE/POLYSTYRENE SEMIINTERPENETRATING POLYMER NETWORKS

The synthesis of pseudo- and semi-interpenetrating polymer networks (IPNs) based on poly-dimethylsiloxane (PDMS) and polystyrene (PS) is described. IPNs were obtained by simultaneous and in situsequential synthesis procedure. The preliminary studies on IPNs properties such as transition temperature,microphase separation and mechanical behaviors have been carried out by using differential scanningcalorimetry (DSC) and scanning electron microscopy (SEM). The experimental evidence clearly showed thatsemi-IPNs obtained by sequential synthesis procedure have higher interpenetrating extent than pseudo-IPNssynthesized by simultaneous procedure. Over the full composition, the PDMS/PS IPNs are immiscible. Thepseudo-IPNs microphase separation can be greatly subdued through the formation of grafting bonds betweentwo networks as well as the kinetic rate-matching of the individual network crosslinking.     

聚[丙烯酸甲酯-甲基丙烯酸2-(二甲氨基)乙酯]/环氧树脂IPN力学性能的研究

用同步法合成聚[丙烯酸甲酯-甲基丙烯酸2-(二甲氨基)乙酯]/环氧树脂(P(MA-DMA)/EP)互穿聚合物网络(IPN),对其力学性能进行了研究,结果表明,该体系IPN由于两网络间接枝导致相客性比较好,动态力学谱仅出现一个转变温度,当P(MA-DMA)/EP=20/80时,力学性能显示正协同效应,对环氧树脂的增韧效果最佳,不同组成比的IPNT_g实-T_g计与(d_实-d_计)差值成正比。     

Interpenetrating Polymer Networks of Uralkyd Resin Based on Hydrogenated Castor Oil and Poly(Butyl Acrylate)

Abstract

Semi‐ and full‐interpenetrating polymer networks (IPNs) of uralkyd (UA) resin based on hydrogenated castor oil and poly(butyl acrylate) (PBA) were prepared by the sequential mode of synthesis. These IPNs were characterized for their resistance to thermal behavior, swelling (%), and mechanical properties. The morphology of the IPNs was studied by scanning electron microscopy (SEM). The effect of the variations of the blend ratios on the above‐mentioned properties was examined. The mechanical properties significantly enhanced by increasing UA component in the blend. Full‐IPNs exhibited higher apparent densities, mechanical properties, and thermal stability than the corresponding semi‐IPNs.     

聚丙烯酸酯/环氧树脂互穿网络聚合物的研究Ⅲ.橡胶态弹性模量和互穿缠结

采用一步法（Ｓｉｍｕｌｔａｎｅｏｕｓｌｙ）合成了双组分的聚丙烯酸酯／环氧树脂互穿网络聚合物（ＩＰＮｓ）．选择预溶胀方法制备了聚丙烯酸酯和环氧树脂两种组分网络．测定了各种组分比的ＩＰＮ和不同溶胀度下的组分网络的动态力学性能，从橡胶态弹性理论出发讨论了ＩＰＮ和预溶胀网络之间在橡胶态弹性模量上的关系，并据此指出互穿缠结增加了网络的有效“交联密度”，因此，它对ＩＰＮ的橡胶态弹性模量有较大的贡献．密度测量的结果也提供了另一方面的证据     

Effect of kinetics on morphology and mechanical properties of poly(allyl diglycol carbonate)-poly(urethane) interpenetrating polymer networks

Simultaneous interpenetrating polymer networks (SINs) of polyallyl diglycol carbonate (ADC) and polyurethane (PU) were prepared by differing modes of synthesis. The kinetics of the network formation of each constituent component was investigated by gel time studies and infra-red spectroscopy. The effect of different rates of network formation of each component on the morphology and mechanical properties were studied by transmission electron microscopy (TEM) and scanning electron microscopy (SEM), dynamic mechanical analysis (DMA), stress-strain, and single edge notch tension. TEM and DMA studies showed a two-phase separated morphology. The extent of phase eparation was dependent on the relative rate of formation of component networks. Thus, simultaneous gelation of both networks showed a fine morphology and exhibited improved toughness over neat ADC resin.     

Polyepichlorohydrin polyurethane/poly(methyl methacrylate) interpenetrating polymer networks

Polyurethane (PU) based on polyepichlorohydrin/poly(methyl methacrylate) (PECH/PMMA) interpenetrating polymer networks (IPNs) was synthesized by a simultaneous method. The effects of composition, hydroxyl group number of PECH, NCO/OH ratio and crosslinking agent content in IPNs were investigated in detail. Some other glycols, such as poly(ethylene glycol), poly(propylene glycol) and hydroxyl-terminated polybutadiene, were also used to obtain PU/PMMA IPNs. The interpenetrating and fracture behaviors of the IPNs are explained briefly.     

Interpenetrating polymer network hydrogels based on silicone and poly(2‐methacryloyloxyethyl phosphorylcholine)

In the present work, sequential interpenetrating polymer networks (IPNs) based on silicone and poly(2‐methacryloyloxyethyl phosphorylcholine) (PMPC) were developed with improved protein resistance. The structure and morphology of the IPNs were characterized by Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). The results showed that the IPNs exhibited heterogeneous morphology. The bulk properties such as water content, ion permeability, and mechanical strength of the IPNs were determined by gravimetric method, ionoflux measurement technique, and tensile tester, respectively. The surface characteristics of the IPNs were investigated by X‐ray photoelectron spectroscopy (XPS) and contact angle measurements. XPS analysis suggested that PMPC was present on the surface as well as in the bulk material. The IPNs possessed more hydrophilic surface than pristine silicone revealed by contact angle measurements. Bovine serum albumin (BSA) was used as a model protein to evaluate protein resistance by a bicinchoninic acid assay method. The result revealed that the protein adsorption on the IPNs was significantly reduced compared to pristine silicone. These results suggest that the IPNs based on silicone and PMPC may be developed as novel ophthalmic biomaterials. Copyright © 2010 John Wiley & Sons, Ltd.     

聚氨酯／聚（苯乙烯－甲基丙烯酸甲酯－甲基丙烯酸）互穿聚合物网络的研究

研究了（蓖麻油－聚乙二醇）聚氨酯／聚（苯乙烯－甲基丙烯酸甲酯－甲基丙烯酸）（ＰＵ／Ｐ（Ｓｔ－ＭＭＡ－ＭＡＡ））互穿聚合物网络（ＩＰＮ）．动态力学性能及透射电镜结果均表明该体系相分离较严重；ＩＰＮ具有两个玻璃化转变温度，它们有不同程度的内移，形成一定程度分子水平的混合，而ＩＰＮ（５０／５０）其分子混合水平较大，互穿缠结程度较高。形成ＩＰＮ后，其力学性能得以改善。透射电镜结果表明，聚氨酯网的交联密度直接影响ＩＰＮ的相区尺寸。形成ＩＰＮ后热稳定性提高，易于降解断链的Ｓｔ－ＭＭＡ－ＭＡＡ单体起到了自由基消除剂的作用。     

POLYIMIDE/INORGANIC INTERPENETRATING POLYMER NETWORKS FOR STABLE SECOND-ORDER NONLINEAR OPTICS

Thermally stable NLO interpenetrating polymer networks (IPNs) based on an organosoluble polyimides functionalized with methacryloyl groups (PIB), and an alkoxysilane dye (ASD) have been developed. IPNs were formed through the free radical polymerization of methacryloyl group containing PIB, and sol-gel process of ASD. Optically clear samples exhibit large second-order optical nonlinearity (d₃₃ = 6.9-39.6 pm/V at 1064 nm) after poling and curing at 180°C for 2 hours. The temporal stability of the PIB/ASD IPN samples was much better than the inter-chain crosslinking polyimide/inorganic samples. The high rigidity of the polymer backbone and the interpenetrating structure of the polymer networks prevent the randomization of the aligned NLO chromophores     

聚氨酯与接枝乙烯基酯树脂互穿网络研究: 自由基共聚 单体的影响

通过分子设计技术合成了两种侧链种类和长度可能控制的接枝乙烯基酯树脂(VER),并用它们与聚氨酯(PU)形成了同步互穿网络(SIN)。通过DSC,SEM,TEM,FTIR等考察了接枝VER的共聚单体对VERSIN的形态结构与力学性能的影响。研究结果表明,用甲基丙烯酸甲酯(MMA)为共聚单体的接枝VER网络中的MMA链段与PU网络中的硬段有较好的相容性,导致这类PU/接枝VERSIN中两个网络间的相容性和互穿程度好于由苯乙烯为共聚单体时合成4SIN。因此,在这两类共聚单体合成的SIN中,由MMA形成的接枝VER网络增强PU网络的效果更为显著。     

Thermal,mechanical, and morphological properties of soybean oil-based polyurethane/epoxy resin interpenetrating polymer networks (IPNs)

A series of interpenetrating polymer networks (IPNs) based on epoxy (EP) resin and polyurethane (PU) prepolymer derived from soybean oil-based polyols with different mass ratios were synthesized. The structure, thermal properties, damping properties, tensile properties, and morphology of soybean oil-based PU/EP IPNs were characterized by Fourier-transform infrared spectroscopy, differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), universal test machine, and scanning electron microscopy (SEM). DSC and DMA results show that the glass transition temperature of the soybean oil-based PU/EP IPN decreases with the increase of PU prepolymer contents. Soybean oil-based PU/EP IPNs have better damping properties than that of the pure epoxy resin. The tensile strength and modulus of PU/EP IPNs decrease, while elongation at break increases with the increase of PU prepolymer contents. SEM observations reveal that phase separation appears in PU/EP IPNs with higher PU prepolymer contents.