Mechanical properties of polyurethane-unsaturated polyester interpenetrating polymer networks

Interpenetrating polymer networks (IPNs) based on a polyurethane (PU) and two unsaturated polyester (UPE) resins (a commercially available UPE and a partially endcapped UPE) were prepared. The mechanical properties, such as tensile strength, elongation at break, impact strength, and dynamic mechnical properties of IPNs, were studied by changing reaction temperature, PU reaction rate, and UPE reaction rate. Owing to the unique microgel formaton of UPE, the first formed network tends t be the dispersed phase in the PU-UPE IPN system. The reaction sequence was found to be an important factor in determining the phase mixing and phase morphology of the IPNs. When the PU reaction was faster, extensive phase mixing due to strong grafting or chain interpenetration was obtained. When the UPE reacted first, grafting was retarded by the microgel formation of the UPE network. It was found that simultaneous reaction of the two reacting system resulted in a co-continuous structure that provided enhanced tensile properties and impact strength.     

Synthesis and properties of unsaturated polyester diol–polyurethane hybrid polymer network

This article deals with the synthesis and properties of poly[(propylene glycol maleate)-co-(propylene glycol phthalate)] diol (PGMPD)/polyester–urethane or polyether–urethane hybrid polymer networks (HPNs). The polyurethane type and the molar ratio of NCO/OH have an effect on their properties. The structure–property relationship is discussed as well. © 1994 John Wiley & Sons, Inc.     

Influence of processing and material variables on resin-fiber interface in liquid composite molding

In this study, systematic investigation of influence of processing variables on the tensile strength and resin-fiber interface of composites prepared by liquid composite molding process was carried out. The variables studied included injection pressure and mold/fiber mat temperature. Fibers were better wetted and bonded at lower injection pressure and higher molding temperature, which resulted in a higher tensile strength of molded composites. Single filament composite tests were also used in conjunction with birefringence studies to characterize interface bonding. Improved interfacial behavior was observed in the case of compatible systems.     

聚酯漆和聚氨酯漆在我国的发展状况

聚酯漆、聚氨酯漆是目前市场上较为流行的涂料品种，本文简介了其品种、产量、新技术以及生产原料方面的发展状况，指出了发展中存在的问题及努力方向。     

Reaction-induced phase separation during the formation of a polyurethane-unsaturated polyester interpenetrating polymer network

In this study, an interpenetrating polymer network (IPN) based on a polyurethane (PU) and a partially end-capped unsaturated polyester (UPE) was prepared. The reaction-induced phase separation process of the IPN was studied using a phase contrast optical microscope and a transmission electron microscope (TEM), while reaction kinetics and onset of gelation were determined by a differential scanning calorimeter and a rheometer respectively. Except at low temperatures, the phase separation patterns were found to follow the spinodal decomposition mechanism. An interconnected phase developed quickly and was followed by coalescence of the periodic phase to form droplet/matrix type of morphology. A second level of phase separation also occurred within both the droplet and the matrix phases in some cases. The domain sizes resulting from both levels of phase separation gradually increased until the structure was locked by chemical gelation. Reaction temperature, PU reaction rate, and UPE reaction rate all had significant effects on the final morphology of the formed IPNs.     

以声学处理聚酯为基础的聚氨酯

以经声学处理过的聚己二酸乙二醇酯（∏b）为基础的聚氨酯可以简化合成工艺,免除聚酯的烘干阶段,且能合成出合格的力学性能优良的聚氨酯。除此之外,还可以缩短聚氨酯的热固化时间及恒温调节时间,达到节能减排和保护环境的目的。     

Analysis of reaction injection molding process of polyurethane-unsaturated polyester blends. Part II: Mechanical properties

The mechanical properties of polyurethane-unsaturated polyester interpenetrating polymer networks (IPNs) that were prepared by reaction injection molding (RIM) process were measured with variations In composition, cross-link density, and relative reaction rate. From dynamic mechanical analysis (DMA), it was found that the two component polymers had a good compatibility over the whole composition range. The tensile strengths of the blends were greater than those of the pure components and had a maximum value at 50/50 composition. The modulus of elasticity and surface hardness decreased and the impact strength increased as the polyurethane content was increased, but the changes were not high at low polyurethane content, below 50%. For higher cross-link density, the compatibility was enhanced and the mechanical properties were improved. When the reaction rates of the components were different, some extent of phase separation was found in DMA and the properties were affected adversely.     

Analysis of reaction injection molding process of polyurethane-unsaturated polyester blends. Part I: Computer simulation

A computer simulation model was developed to analyze the reaction injection molding (RIM) process of polyurethane and unsaturated polyester blends. The reaction kinetics and viscosity functions of each component were obtained through actual experiments, and a mathematical scheme for numerical calculation was set up in cylindrical coordinates to predict the temperature and conversion profiles within a disc-type mold. The temperature change calculated from the simulation was compared with the temperature rise measured in actual RIM experiments. The effects of the feed temperature, wall temperature, and catalyst levels on the maximum exothermic temperature and the demolding time were evaluated in a search for the optimum processing conditions.     

Moisture-cured polyurethane based on polyester and polycarbonate polyols

Moisture-cured polyurethanes were prepared by reacting toluene diisocyanate and sebacic acid-based hydroxy esters such as ethylene glycol sebacate, propylene glycol sebacate, diethylene glycol sebacate, and polyester polyols such as poly(ethylene glycol sebacate), poly(propylene glycol sebacate), poly(diethylene glycol sebacate), and poly(butane diol sebacate). The effect of molecular weight of the esters on film properties and the catalytic effect of 3–5% triethylamine, triethanolamine, and 2-diethylaminoethanol on curing of such films were investigated. Polyurethanes were also prepared using a blend of poly(butane diol carbonate) polyol with polyester polyols. Best polyurethane compositions were obtained when sebacic acid-based polyester polyols were blended with poly(butane diol carbonate) polyol in the ratio of 3:2. These polyurethanes show good tensile strength (120–215 kg/cm²) and elongation (340–460%) properties, having high melting points (247–268°C) and good resistance to solvents and chemicals. Moreover, they are colorless and transparent.     

聚酯型阳离子水性聚氨酯乳液的合成研究

采用聚酯二醇(JW2503)、甲苯二异氰酸酯(TDI)、N-甲基二乙醇胺(MDEA)为基本原料，用丙酮法合成了聚酯型阳离子水性聚氨酯乳液。讨论了NC0／OH量比、MDEA的加入方式及其用量、反应温度等因素对乳液性能的影响。实验结果表明，当合成条件为：NCO／OH量比为2．7，MDEA的用量占树脂的6％-7％，且采用饥饿加料的方式滴加MDEA，初聚体合成温度为60—65℃，引入亲水扩链基团的扩链反应温度为40℃，中和度90％-100％时，合成的聚酯型阳离子水性聚氨酯乳液具有较好的贮存稳定性，且涂膜的耐水性和机械性能良好。     

以废聚酯制备聚氨酯涂料

以2,4–甲苯二异氰酸酯与三羟甲基丙烷制备了含有─NCO的A组分,将废聚酯通过醇解、酯化、缩聚等步骤制得不饱和聚酯,再与N,N–二甲基苯胺混合均匀作为含有─OH的B组分,将A、B两组分混合制得聚氨酯涂料。讨论了A、B组分的合成工艺,获得了最佳合成条件:制备A组分时,m(TDI)∶m(TMP)=3.86~3.89,θ=(85±5)°C,t=1~1.5h;制备B组分时,θ(醇解)=190~210°C,t(醇解)=3~3.5h;θ(酯化)=130~150°C,t(酯化)=100min;θ(缩聚)=200°C。当mA∶mB=1.05∶1时,所得涂膜表面坚硬光滑,附着力0级,硬度6H,耐水性测试240h无变化,盐雾试验48h无变化。     

Study on phase behavior–impact strength relationship of unsaturated polyester/polyurethane hybrid polymer network

The phase behavior of a hybrid polymer network (HPN) composed of poly[(propylene glycol maleate)-co-(propylene glycol phthalate)] crosslinked with styrene and polyester–urethane crosslinked with methylene-bis-ortho-chloroaniline was examined. The correlation between phase separation and impact strength of the HPNs is discussed. The composition of HPNs has an effect on their properties.     

Polystyrene and polyester polyurethane elastomer blends compatibilized by SMA

Blends of polystyrene (PS) with polyester polyurethane elastomer (PU‐es) were compatibilized by addition of poly(styrene‐co‐maleic anhydride) (SMA) containing 7 wt % of maleic anhydride. Binary nonreactive (PS/PU‐es) blends, binary reactive (SMA/PU‐es) blends, and ternary reactive blends (PS/SMA/PU‐es) were prepared with 10 and 20 wt % of PU‐es. The maleic anhydride content in the ternary reactive blends was varied through addition of different SMA amounts from 0.5 to 5 wt %. Polyurethane in the blends was crosslinked by using dicumyl peroxide or sulfur to improve its mechanical properties. The experimental processing conditions, such as temperature and rotor speed in an internal mixer, were analyzed before blend preparation by processing the individual polymers, PS and SMA, and the PS/PU‐es nonreactive blend (90/10), to prevent the degradation of the polymer during melt mixing and to assure macroscopic homogeneity. The torque behavior during the mixture indicated a grafting copolymerization, which was responsible for the significant drop of the PU‐es domain size in the glassy matrix, as observed by scanning electronic microscopy (SEM). The miscibility of the glassy matrix, which was shown to be dependent on the composition and the phase behavior of ternary blends, became very complex as the SMA concentration increased, as concluded from dynamical–mechanical analysis. Blends containing 20 wt % of PU‐es presented an increase up to a factor of 2 in the deflection at break in relation to PS. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2297–2304, 2004     

聚氨酯改性不饱和聚酯的徽观结构与性能

利用与天然纤维具有良好亲和性的聚酯聚氨酯(PU)改性不饱和聚酯(UP),通过扫描电镜（SEM）、傅里叶红外光谱（FT-IR）、接触角和力学性能等,研究了改性不饱和聚酯的微观结构、反应程度和主要性能.研究结果表明,引入PU提高了不饱和聚酯树脂的韧性,增加了与天然纤维的界面浸润性,降低了不饱和聚酯树脂的固化收缩率.所得改性不饱和聚酯的冲击断裂截面表现为韧性断裂;与天然纤维的接触角随着聚氨酯添加量的增加而降低,表明改性不饱和聚酯与天然纤维的浸润性增强.力学性能测试表明,当PU含量为5%时,其冲击强度可提高80%,弯曲模量降低小于20%,固化收缩率低于4%.     

The swelling behavior of interpenetrating polymer networks composed of polyurethane and unsaturated polyester

The kinetics of swelling and the sorption performance were observed for the polymer compositions with interpenetrating polymer networks made up of polyurethane and unsaturated polyester during their exposure to chlorobenzene at 25°C. It was found that the rates for solvent transport and solvent absorption processes were controlled by the chemical composition of the formulation studied. On the basis of the observed swelling process, parameters could be assessed which were specific for the mass transfer process, i.e., diffusion coefficient, sorption coefficient, and permeability coefficient. Moreover, an attempt was made to evaluate structural parameters that describe topology of the obtained networks. It was found that the increasing share of polyurethane in the composition reduced crosslinking density in the polyester network that resulted in faster diffusion of the solvent and higher sorption capacity for the solvent. The higher the styrene content in the composition, the higher the crosslinking density in the system, and hence the diffusion of solvent and its sorption inside the polymer network was much more difficult. In the scanning electron microscope analysis of samples, which had been subjected to swelling, no leaching was observed for any phase present in the system, despite phase separation for both the components. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3511–3519, 2006     

聚氨酯型不饱和聚酯涂料的研究

通过对反应过程中和涂膜酸值和粘度测定以及涂膜性能测定和红外光谱分析研究了聚氨酯型不饱和聚酯树脂的反应温度、反应时间、醇酸比、TDI用量、饱和酸与不饱和酸配比、交联剂聚苯乙烯用量等对涂料性能的影响。研究表明:反应温度170℃,反应时间3 h,乙二醇、邻苯二甲酸酐与顺丁烯二酸酐物质的量比为1.4:3:7,—NCO与—OH物质的量比为1:1,每15 g树脂中加入交联剂苯乙烯5 g,固化体系0.3 g,填料10 g,可制得物理力学性能较好的聚氨酯型不饱和聚酯涂料,涂膜硬度为5 H,附着力1级,柔韧性0.5 mm,抗冲击性50 cm。     

Modification of unsaturated polyester resin by polyurethane prepolymers

Unsaturated polyester resins (UPRs) are extensively used by the fiber‐reinforced plastic (FRPs) industry. These resins have the disadvantages of brittleness and poor resistance to crack propagation. In this study, UPRs were chemically modified by reactive blending with polyurethane prepolymers having terminal isocyanate groups. Hybrid networks were formed by copolymerisation of unsaturated polyesters with styrene and simultaneous reaction between terminal hydroxyl groups of unsaturated polyester and isocyanate groups of polyurethane prepolymer. The prepolymers were based on toluene diisocyanate (TDI) and each of hydroxy‐terminated natural rubber (HTNR), hydroxy‐terminated polybutadiene (HTPB), polyethylene glycol (PEG), and castor oil. Properties like tensile strength, toughness, impact resistance, and elongation‐at‐break of the modified UPRs show considerable improvement by this modification. The thermal stability of the copolymer is also marginally better. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 449–456, 2006     

聚酯型水性聚氨酯油墨连接料的研究

以聚酯二元醇、二异氰酸酯和二羟甲基丙酸(DMPA)为主要原料,合成了聚酯型水性聚氨酯(WPU)乳液。研究了聚酯二元醇的种类、R值[R=n(-NCO)/n(-OH)]和DMPA用量等对WPU乳液的附着力、稳定性和T型剥离强度等影响。结果表明:以Pol-356(由己二酸、乙二醇和1,4-丁二醇聚合而成)为聚酯二元醇、端羟基聚酯多元醇(Pol-350)为小分子扩链剂,当w(DMPA)=9%、R值为1.200～1.225时,制成的WPU乳液固含量高、储存稳定性好,其对非极性BOPP(双向拉伸聚丙烯)薄膜等具有相对较高的附着力和T型剥离强度。     

Manufacture and use of pulverized flexible polyester polyurethane foam particles

Crucial process modifications were shown necessary to improve the economics of cryogenic grinding of flexible polyurethane (PU) foam. It is concluded that foam densification prior to cryogenic processing was essential to reduce insulation effects. In comparative studies of foam and densified foam, increasing the density to ～800 kg/m³ resulted in dramatically reduced cryogen use and vastly improved output. Results indicated that cryogenic pulverization presents a significantly more economic solution than previously recognized. Particles produced by this method were added to foam formulations and effects of particle size and structure on compression properties and cell structure of resultant foams were studied. Particle sizes <100 μm gave similar compression properties and cell size to virgin foam at up to 10 parts by weight on 100 parts of polyol, but cell structure and compressive properties showed increasing divergence as particle size and addition concentration increased. Studies of alternative uses showed that the PU particles showed promise as fillers in rigid PU foam formulations and suggested an extending or reinforcing action in natural rubber vulcanizates.     

Some epoxidized polyurethane and polyester resins based on linseed oil

Linseed oil was epoxidized in situ with perbenzoic or peracetic acid to produce epoxidized linseed oil (I). Effect of type and concentration of the peracid and the reaction time on the characteristics of the produced epoxidized oil were studied. Various epoxidized polyurethanes (II) with different NCO/OH ratios as well as epoxidized polyesters (III) were prepared from (I). The results obtained for the evaluation of resins (II) and (III) show promising applicability as petroleum pipeline coatings. © 1995 John Wiley & Sons, Inc.