热塑性聚氨酯热熔胶的合成与性能研究

以己二酸系聚酯二醇为软段,二异氰酸酯与扩链剂生成的链段为硬段,制备了聚氨酯热熔胶;研究了软硬段组成、结构、相对分子质量、扩链剂、异氰酸酯指数等对聚氨酯热熔胶的力学性能、结晶性能、粘接性能及耐热性能的影响。     

热塑性弹性体型热熔压敏胶的研究进展

介绍了热熔压敏胶用热塑性弹性体以及增粘树脂的特点、作用以及研究进展,并对热熔压敏胶的发展方向以及应用前景进行了展望。     

Monitoring nonisothermal crystallization of thermoplastic polymers using a quartz crystal resonator

A new monitoring device for the nonisothermal crystallization of thermoplastic polymers, polyethylene, polypropylene, polystyrene, and polyamide, is developed utilizing a quartz crystal resonator, and its performance is evaluated by comparing the measurements with the results of DSC thermoanalysis and microscopic observation. The experimental results of four different polymers indicate that the variation of resonant freency of the quartz crystal resonator is a good means to monitor the crystallization process. Though the measurements of melting and crystallization are close to the DSC outcome, more deviation is observed with the new device. The change in crystalline morphology during the crystallization process is also detected from the slope changes of the frequency decrease. In comparison with the microscopic observation of polymer films, it is found that the processes of nucleation and crystal growth in nonisothermal crystallization can be explained with the variation of the resonant frequency of the quartz crystal resonator. In addition, crystallization kinetics is modeled with the Avrami equation. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Preparation and characterization of siloxane-containing thermoplastic polymides

Copolyimides and homopolyimides of bis(γ-aminopropyl)tetramethyldisiloxane and 3,3′-diaminobenzophenone have been prepared with benzophenonetetracarboxylic dianhydride. The properties of the copolyimides were compared with those of the homopolyimides to assess the effect of incorporation of siloxane groups in the backbone. Applications of the polymers as adhesives and mouldings are discussed.     

IPDI／PEPA型热塑性聚氨酯的合成及表征

以异佛尔酮二异氰酸酯(IPDI)、聚己二酸乙二醇丙二醇酯二醇(PEPA)和1,4-丁二醇(BDO)为原料,用熔融预聚合两步法,后聚合温度60-90℃,合成硬段含量为50％的IPDI／PEPA型热塑性聚氨酯。采用凝胶渗透色谱仪测试其数均相对分子质量为78 650,重均相对分子质量为125 446,相对分子质量分布为1．59。红外光谱分析表明聚合较为完全,聚合物不存在支链结构,为热塑性材料。DSC分析表明聚合物软段和硬段的玻璃化转变温度分别为-34℃和48℃,透射电镜照片进一步说明该材料存在一定的相分离。     

热塑性弹性体在封边热熔胶中的应用

制备出增韧家具封边热熔胶,主要组分为EVA树脂、热塑性弹性体A、松香衍生物、松香、填料等。经检测,软化点92℃,拉伸强度大于4 MPa,断裂伸长率150%,原材料成本低于10元/kg。     

Processing study of a high temperature adhesive

An adhesive-bonding process cycle study was performed for a polyimidesulphone. The high molecular weight, linear aromatic system possesses properties which make it attractive as a processable, low-cost material for elevated temperature applications. The results of a study to better understand the parameters that affect the adhesive properties of the polymer for titanium alloy adherends are presented. These include the tape preparation, the use of a primer and press and simulated autoclave processing conditions. The polymer was characterized using Fourier transform infrared spectroscopy, glass transition temperature determination, flow measurements, and weight loss measurements. The lap shear strength of the adhesive was used to evaluate the effects of the bonding process variations.     

Design and properties of a series of high‐temperature thermoplastic elastomeric blends from polyamides and functionalized rubbers

A series of high‐temperature thermoplastic elastomers (TPEs) and thermoplastic vulcanisates (TPVs) were successfully developed based on two different types of heat resistant polyamide (PA) (25 parts by weight)—PA‐12 and PA‐6, in combination with three different functionalized rubbers (75 parts by weight) of varying polarity, e.g., maleic anhydride grafted ethylene propylene diene terpolymer (MA‐g‐EPDM), sulphonated ethylene propylene diene terpolymer, and carboxylated acrylonitrile butadiene rubber, by melt mixing method. These rubbers have low level of unsaturation in its backbone, and the plastics showed high melting range. Thus, the developed TPEs and TPVs were expected to be high temperature resistant. Resol type resin was used for dynamic vulcanization to further increase the high temperature properties of these blends. Interestingly, initial degradation temperature of the prepared blends was much higher (421 °C for MA‐g‐EPDM/PA‐12) than the other reported conventional TPEs and TPVs. Fourier transform infrared analysis described the interactive nature of the TPEs and TPVs, which is responsible for their superior properties. The maximum tensile strength with lowest tension set was observed for the carboxylated acrylonitrile butadiene rubber/PA‐12 TPV. Mild increase in mechanical properties without any degradation was observed after recycling. Dynamic mechanical analysis results showed two distinct glass transition temperatures and indicated the biphasic morphology of the blends, as evident from the scanning electron microscopy. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45353.     

SEPS热塑性弹性体的催化专利进展

概述新型热塑性弹性体氢化苯乙烯-异戊二烯-苯乙烯嵌段共聚物(SEPS)的性能、用途以及市场需求,介绍国内外研究开发的催化剂动向,并分析催化剂专利申请状况,提出国内发展SEPS工业项目的必要性。国内专利申请涉及的催化剂主要有有机酸盐类、茂金属类、四烃基钛类。目前世界上占主导地位的热塑性弹性体是苯乙烯类热塑性弹性体(SBCs),产品以SBS、SIS以及相应氢化产品SEBS和SEPS等为主。     

热塑性树脂改性氰酸酯树脂的相结构表征

采用异步合成法制备了聚甲基丙烯酸甲酯(PMMA)、聚苯乙烯(PST)、聚丙烯腈(PAN)与氰酸酯(CE)的共聚物,比较了3种热塑性树脂对共聚物力学性能、玻璃化温度(Tg)、转化率及反应活化能的影响,并讨论了共聚物的相图变化、微观结构与宏观性能之间的联系以及催化剂对改性体系相结构的影响。结果表明,当加入质量分数为15%的PMMA时,改性体系的冲击强度和弯曲强度比纯氰酸酯树脂分别提高了94.99%和29.90%,玻璃化温度提高了约30℃。改性体系经150℃固化,转化率可提高90%以上。改性体系的相结构随PMMA含量增加依次出现分散相、双连续相和相反转结构,在临界点(m(PMMA)=15%)附近可形成双连续相结构。相尺寸和相间距随固化温度升高而加大。共聚物中热塑性树脂的含量和共聚物的固化工艺对共聚物的相结构有较大影响,通过相结构的转变,进而影响到共聚物性能,拓展了其应用范围。     

Synthesis and characterization of thermoplastic polyurethanes as binder for novel thermoplastic propellant

Two series of thermoplastic polyurethanes (TPUs), which used nitroester plasticiable tetrahydrofuran‐ethylene oxide random copolyether as soft segment and adduction products of isophorone diisocyanate (IPDI) and toluene diisocyanate (TDI) with 1,4‐butanediol as hard segments respectively, were successfully synthesized as binders for novel thermoplastic propellant. Mechanical tests and DSC techniques were applied to make characterizations of the polymers in order to choose candidate materials. Results shown that the TPU based on IPDI with fraction of the hard segment around 45% will meet requirements of propellant in terms of mechanical properties and glass transition of the soft segment phase. The results were further manifested in detail by quantitative studies of the degree of microphase separation as well as hydrogen bonding within the hard segment domain based on the equations established through FTIR and DSC analyses. It was found that mixing of two phases, which mainly referred to the mount of the hard segment dissolving into the soft segment phase, was as little as 10% in IPDI series TPUs, whereas it was almost up to 30% in TDI series. This indicated that better phase separation was achieved in IPDI series TPU. By contrast, studies of hydrogen bonding in domain revealed that the domain of TPUs prepared with TDI was much oriented in comparison with that with IPDI, which indicated higher processing temperatures. The results were raised by the melting index results under required conditions. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2961–2966, 2002; DOI 10.1002/app.2324     

High-performance thermoplastic polyurethane nanocomposites induced by hybrid application of functionalized graphene and carbon nanotubes

A hybrid polymeric system containing carbon nanofillers with different geometrical dimensions is proposed for strategic applications, particularly for electrical properties. Two different carbon nanofillers including functionalized multiwalled carbon nanotubes (fCNTs) and functionalized graphene nanoplatelets (fGnPs) were added to thermoplastic polyurethane (TPU) to prepare single and hybrid nanofiller filled TPU through solution mixing. Sufficient exfoliation of the fGNPs in the single nanocomposites was confirmed by X-ray diffraction, while single filler and hybrid TPU nanocomposites containing fCNTs showed some re-aggregation of these nanofillers. Linear rheology together with scanning electron microscopy revealed a proper exfoliation and dispersion degree for fGnPs and fCNTs, respectively. We have shown that simultaneous addition of fCNTs–fGnPs in the form of a hybrid system into the TPU made a large surface area available and strong interfacial interactions were formed between the hybrid network and the TPU matrix. This in turn led to electrical, thermal and mechanical properties, which were superior to those predicted by the mixture law. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48520.     

Studies on mechanical characterization and water resistance of glass fiber/thermoplastic polymer bionanocomposites

This experimental work is aimed at studying the performance of rice husk flour/glass fiber reinforced high density polyethylene hybrid nanocomposites. To meet this objective, the nanoclay was compounded with high density polyethylene (HDPE), rice husk flour (RF), glass fiber, and coupling agent in an internal mixer; then, the samples were fabricated by injection molding. The concentration was varied from 0 to 6 per hundred compounds for nanoclay and from 0 to 15% for glass fiber, individually. The amount of coupling agent was fixed at 2% for all formulations. The morphology, water absorption, thickness swelling, and mechanical properties of nanocomposites were evaluated as a function of nanoclay and glass fiber contents. The results indicated that both modulus and strength were improved when glass fibers were added to the composites system but impact strength and moisture absorption further decreased with the increase of glass fiber content. The morphology of the nanocomposites has been examined by using X‐ray diffraction. The morphological findings revealed that the nanocomposites formed were intercalated. The mechanical analysis showed that the biggest improvement of the tensile and flexural modulus and strengths can be achieved for the nanoclay loading at 4 per hundred compounds. However, further increasing of the loading of nanoclay resulted in a decrease of impact strength. Finally, it was found that addition of nanoclay reduced the water absorption and thickness swelling of the composites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

乳聚丁苯互穿网络型热塑性弹性体的制备

以丁苯胶乳为种子乳液,苯乙烯、甲基丙烯酸甲酯、丙烯腈或它们的混合物的硬单体,用氧化还原引发体系,经种子乳液聚合法同备出复合乳液,絮凝干燥后所得互穿聚合物网络可热塑性反复加工。考察了硬单体的种类和用量、交联剂的种类及用量、反复加工次数对聚合物力学性能的影响。用透射电子显微镜观察了乳胶粒微观形态,结果表明：用混合单体,聚合物力学性能较优,以３５份Ｓｔ＾＋ＭＭＡ为第二单体制备的聚合物的攫断伸长率为４００％,拉伸强度为９．３ＭＰａ,３００％定伸应力为７．６ＭＰ,撕裂强度为７３．９ｋＮ．Ｍ＾－１,邵尔Ａ型硬度为８４。     

Development of novel polar thermoplastic vulcanizates based on ethylene acrylic elastomer and polyamide 12 with special reference to heat and oil aging

Thermoplastic vulcanizates (TPVs) based on ethylene acrylic elastomer (AEM) and polyamide 12 (PA12) have been developed by the dynamic vulcanization process, in which selective cross‐linking of the elastomer phase (AEM) during melt mixing with the thermoplastic phase (PA12) has been carried out simultaneously. TPVs at varied blend ratios (50 : 50, 60 : 40, 70 : 30) of AEM/PA12 were prepared at 185°C at a rotor speed of 80 rpm up to 5 min of mixing. Di‐(2‐tert‐butyl peroxy isopropyl) benzene (DTBPIB) was chosen as the suitable cross‐linking peroxide to carry out the dynamic vulcanization. Morphology study reveals the development of continuous agglomerate of rubber network in case of all the TPVs took place and the average dimension of the rubber particles are in the range of 30–40 nm. TPV based on 50 : 50 AEM/PA12 shows better physicomechanical properties, thermal stability, and dynamic mechanical behavior among all the TPVs. For aging test, TPVs were exposed to air, ASTM oil 2 and 3. Air aging tests were carried out in hot air oven for 72 h at 125°C, while the oil aging tests were carried out after immersion of the samples into the oils in an aging oven. After aging, there are only slight deterioration of physicomechanical properties of the TPVs. Particularly in case of 50 : 50 blend of AEM/PA12, the retention of the properties even after aging was found excellent. The recyclability of these new TPVs is also found to be excellent leading to find potential application in automotives. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42655.     

The Evolution of a Polyurethane Dental Adhesive System

Screening of common adhesives showed that polyurethanes, as a class, to be most suitable for adhering to wet tooth tissue. The isocyanate groups in the adhesive may react with the tooth mineral; this view is supported by a number of approaches, including measuring γ_c at several humidities, which may be interpreted as showing tooth tissue surfaces to be rich in hydroxyl groups. The bonding of polyurethanes to enamel could be improved by pre-treatments (including acid etching and acetone drying) and by proper choice of polyol, fillers, and coupling agents. From scanning electron micrographs the etching is interpreted to debride a weak boundary layer. The preferred formulation was a TiO₂-filled polyurethane formed from equal weights of castor oil and polymethylene polyphenyl isocyanate catalyzed by from 1 ½ to 10% of tin octoate. Joints of teeth bonded with polyurethanes withstood long-term exposures to water and synthetic saliva and dental restorations in rabbits appeared to adapt well.     

羟甲基化木质素用量对PVC/NBR热塑性弹性体性能的影响

研究了羟甲基化木质素用量对PVC/NBR热塑性弹性体结构与性能的影响。结果表明：在100份（质量,下同）PVC/NBR中加入30份羟甲基化木质素时产物的综合性能最佳,拉伸强度25.6MPa,扯断伸长度520%,邵尔A型硬度77,撕裂强度72.7kN/m;耐老化性能在羟基甲基化木质素用量低于30份时较好;随着羟甲基化木质素用量增加,产物的耐油性能显著提高,动态粘弹分析证实羟甲基化木质素与PVC和NBR有较强的结合力,并且提高了PVC和NBR两相间的相容性。TEM观测发现木质素可在材料中形成第二个连续相,从而与基质构成互穿聚合物网络。     

Preparation and characterization of polyacrylate/polymerized rosin composite emulsions by seeded semicontinuous emulsion polymerization

Polyacrylate/polymerized rosin composite emulsions were prepared by seeded semicontinuous emulsion polymerization of acrylate monomers in which polymerized rosin was dissolved. The effects of polymerized rosin content on the polymerization stability, monomer conversion, polymer structure, and adhesive properties were studied. Polyacrylate/polymerized rosin composites were characterized by gel permeation chromatograph (GPC), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and thermogracvimetry (TG). The results showed that with an increase of polymerized rosin content from 0 to 6 wt %, gel fraction and sol molecular weight decreased obviously but monomer conversion was basically unchanged. In contrast, with a further increase of polymerized rosin content, the decreasing rates of gel fraction, and sol molecular weight were slowed down. Meanwhile, monomer conversion decreased remarkably. Moreover, interface failure changed into cohesive failure after the addition of polymerized rosin, and the peel adhesion and shear resistance of composite latex films declined with the increase of polymerized rosin content. Thermal analysis showed that polymerized rosin and polyacrylate were compatible and the composite latex films had good thermal stability. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

世界热塑性弹性体发展现状

综述了世界上各种热塑性弹性体的发展现状及趋势，论述了它们在橡胶工业的应用情况及前景。