MCPA6预聚体嵌段共聚物性能研究

由端羟基聚丁二烯(HTPB与甲苯二异氰酸酯(TDI–80反应,合成—NCO封端预聚体,以此预聚体活化己内酰胺单体,在NaOH作用下,由活化的己内酰胺开环聚合,制得MCPA6–预聚体嵌段共聚物。改变预聚体添加量,可制得性能不同的嵌段共聚物。研究发现,随预聚体量的增加,嵌段共聚物材料的断裂伸长率升高,硬度、拉伸强度降低,吸水率呈下降趋势,而密度略有降低,表明预聚体对MCPA6有明显的改性作用。     

聚醚型聚氨酯预聚体增韧MC尼龙的研究

将聚醚型预聚体与己内酰胺单体共聚,制备单体浇铸尼龙(MC尼龙)/聚氨酯共聚物。研究了预聚体的异氰酸指数(R=—NCO/—OH)和预聚体质量分数对MC尼龙/聚氨酯共聚物的力学性能、维卡软化温度和结晶度的影响。结果表明:PPG和PTMG预聚体对MC尼龙的增韧效果较好,且PTMG预聚体在R=1.6、质量分数为10%时增韧效果最好,缺口冲击强度达到23.1kJ/m2。随聚氨酯预聚体质量分数的增加,MC尼龙的维卡软化温度逐渐下降,结晶度和熔点均降低。     

聚醚酰胺嵌段共聚物的合成及表征

采用熔融缩聚法合成了聚酰胺(PA)6/聚四氢呋喃(PTEMG)嵌段共聚物,研究了PA6、PTEMG链段的相对分子质量、含量对嵌段共聚物热性能的影响,通过傅立叶变换红外光谱、核磁共振、差示扫描量热、热重测试等对产物进行分析.结果表明,嵌段共聚物以羧基封端,当PA6、PTEMG链段相对分子质量分别为2 000、1 000时,共聚物的分子序列长度最长,相对分子质量最大;PTEMG链段相对分子质量越小,共聚物的熔点越低;PTEMG链段相对分子质量相同时,随PA6链段相对分子质量的增加,熔点升高;嵌段共聚物中PA6组分的熔融温度范围随着PTEMG含量的增加而逐步变宽;共聚物具有较高的热分解活化能.     

聚醚改性铸型尼龙的研究

介绍了聚醚改性铸型尼龙的制备方法，以聚醚和异氰酸酯为原料合成预聚体活化剂在该活化剂存在下引发己内酰胺阴离子聚合，聚体韧性被显著改善。讨论了各各绎制备过程的影响，并测试了制品性能与预聚体用量的关系，当预体用量为聚合体重的８％时，材料缺口冲击强度最高。     

单体浇铸尼龙的增韧改性研究

本论文论述了单体浇铸尼龙的增韧改性制备方法，在绝热条件下通过己内酰胺与十二内酰胺活化阴离子共聚制得冲击强度显著改善的浇铸尼龙制品。探讨了增韧改性单体浇铸尼龙的合成工艺、反应条件及聚合成型过程，研究了十二内酰胺共聚单体对制品试样球晶结构和机械性能的影响。     

聚醚型聚氨酯预聚体合成工艺研究

以聚醚多元醇和异氰酸酯为原料合成聚氨酯预聚体。通过测定—NCO的含量,研究了预聚反应时间和反应温度对预聚反应的影响;研究了R值[n(—NCO)/n(—OH)],反应时间和温度对预聚物黏度的影响,并探讨了预聚反应过程中含水量、预聚体贮存时间对弹性体性能的影响。     

嵌段型聚醚聚二甲基硅氧烷的合成及其界面性能

用1,1,3,3-四甲基二硅氧烷(D2H)和八甲基环四硅氧烷(D4)为原料,经酸催化平衡反应先制得双端含氢聚二甲基硅氧烷(PHMS),再将其和单烯丙基聚乙二醇甲基醚在铂催化下经硅氢加成反应合成嵌段型聚醚聚二甲基硅氧烷(PEPS).用IR和1HNMR对PEPS的结构进行了表征,并通过测定PEPS水溶液的平衡表面张力研究了其表面活性.结果表明,PEPS具有良好的表面活性,其临界胶束浓度(cmc)为0.7 g·L-1,cmc处的表面张力为25.5 mN·m-1.质量分数0.05%的PEPS水溶液在塑料薄膜上30 s时的接触角为37.2°(水在塑料薄膜上30 s时的接触角为59.3°),而铺展面积是水的5倍.     

抗静电剂对单体浇铸尼龙性能的影响

采用己内酰胺、氢氧化钠、甲苯二异氰酸酯及抗静电剂为原料,通过阴离子聚合制备了抗静电单体浇铸尼龙(MC尼龙)。考察了抗静电剂种类及用量对MC尼龙的表面电阻率和体积电阻率的影响,并研究了其对MC尼龙力学性能的影响。结果表明,加入抗静电剂后有效地降低了MC尼龙的表面电阻率和体积电阻率,且在一定的用量范围内,对力学性能有一定的增强作用。     

尼龙6弹性体的合成

以ε－己内酰胺（CL）的水解开环聚合法为合成路线，采用正交试验法求得了较佳基本配方与反应条件；聚醚选用PTMG1000，催化剂选有亚磷酸三苯酯，抗氧化剂和Irganox1098，适宜的反应温度为250－260℃，适宜的开环反应时间为2－3h，预缩聚0.5-1h，后缩聚0.5-2h。在此条件下，不存在反应体系相容性问题，可以合成出颜色浅，摩尔质量较高的N6型尼龙6弹性体（TPAE）树脂。通过对比试验，发现在适宜反应温度和开环反应时间下，采用对苯二甲酸作原料能显著提高CL的转化率。     

尼龙弹性体增韧尼龙6性能研究

为考察尼龙弹性体(TPAE)作为增韧剂使用的性能,使用马来酸酐接枝乙烯-辛烯共聚物(POE-g-MAH)和两种TPAE(硬度分别为30D,45D)作为增韧剂添加至尼龙6树脂,研究不同增韧剂添加量情况下,改性尼龙6的性能的变化规律.研究发现,材料的拉伸强度、弯曲强度、耐热性能和流动性都随着增韧剂用量的增加而下降,而且下降...     

Structure and properties of polylactide toughened by polyurethane prepolymer

In this study, polyurethane prepolymer (PUP) was prepared by the reaction of Poly‐1,4‐butylene glycol adipate diol (PBA) and 4,4′‐Methylenedi‐p‐phenyl diisocyanate (MDI). The as‐prepared PUP was then blended with Polylactide (PLA), and the impact of the PUP on the blends regarding their structure and properties were thoroughly analyzed. Also, PLA was blended with PU powder without isocyanate groups (NCO) as an important control sample (PLAPW) to study the interface interaction of the blends. Obvious yield and neck stretch were obtained after the addition of PUP, and the elongation ratio at break increased from 2.9% to 231.5%. In contrast, the mechanical properties of PLAPW decreased significantly mainly due to the simple physical blending of the polymers without the formation of covalent bonds. Also, the results of the FTIR, SEM, DSC, and DMA analysis showed that the reactions of NCO groups in PUP with the terminal hydroxyl or carboxyl groups in PLA significantly improved the compatibility of the PUP and PLA blend. Compared to pristine PLA, the highest decomposition temperature of the PLA and PUP blend (PLAPU) increased from 359.3°C to 362.6°C. Additionally the thermal stability and mechanical properties of the blended materials were exceedingly improved even with only 5% of PUP in the blended materials. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42983.     

PTMG型聚氨酯预聚体的研制

以聚四亚甲基醚二醇（PTMG）和甲苯二异氰酸酯（TDI）为原料，研究了TDI/PTMG的摩尔比和制备工艺条件，制备出了聚氨酯预聚体。结果表明，当TDI/PTMG的摩尔比为1.80-1.85，且在将PTMG分批加入TDI中的制备工艺条件下可制得相对分子质量分布窄，游离TDI质量分数低，黏度小，稳定性及可操作性能好的聚氨酯预聚体。     

Preparation and properties of wear-resistant and flame-retardant polyphenylsulfoneurea/monomer casting nylon copolymers

A poly(phenylsulfone)-urea (PPSUU) macro-activator is synthesized by in situ anionic polymerization of 4,4′-diaminodiphenylsulfone and hexamethylene diisocyanate. The PPSUU segment is embedded into the nylon molecular chain through copolymerization to improve the wear resistance and flame retardancy of monomer cast nylon 6 (MC PA6) materials. The mechanical properties, thermal stability, friction and wear properties and combustion heat release rate of copolymers with different macro-activator contents are tested. Results indicate that a small amount of PPSUU can improve the wear resistance and impact properties of nylon materials. The wear loss of MC nylon is 54.8% less than pure MC nylon from 1.049 × 10⁻⁸ to 0.474 × 10⁻⁸ g/Nm with 6 wt% PPSUU. Moreover, better flame retardancy is verified. The peak of HRR reduced 36.8% from 654 to 413 kw/m² with 4 wt% PPSUU, accompanied by advanced ignition time and flame extinction time, thus reducing the risk of fire.     

Chemically functionalized SiO2 to improve mechanical properties of oil-impregnated monomer casting nylon

ABSTRACT: Toluene-2,4-diisocyanate and dodecanol were used to chemically functionalize nanosilica (TDID-SiO₂). Composites of TDID-SiO₂ and oil-impregnated monomer casting nylon (OMC nylon) were prepared by an in situ anionic ring-opening polymerization. The dispersion of the TDID-SiO₂ in oil was studied along with the mechanical and friction properties of the composites. The results show that the dispersion of the TDID-SiO₂ in oil was significantly enhanced. Specifically, some TDID-SiO₂ was wrapped in oil droplets, and the size of the oil droplets increased from 2.3 to 3.3 μm for 0–0.125 wt % of the TDID-SiO₂ nanoparticles, which was confirmed by scanning electron microscopy. The composites exhibited excellent mechanical properties when 0.10 wt % TDID-SiO₂ was integrated into OMC nylon. The tensile strength, elastic modulus, notched impact strength, flexural strength, and flexural modulus increased by 6.9%, 7.1%, 33.2%, 15%, and 77.5%, respectively, compared to OMC nylon without TDID-SiO₂ nanoparticles. The friction coefficient was effectively controlled and the abrasion quantity was reduced. Thermogravimetric analysis showed that the thermal decomposition temperature was also improved. The improved mechanical and frictional properties of TDID-SiO₂/OMC nylon composite will enhance its application in wear-resistant products in heavy industry. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 46994.     

湿固型聚氨酯胶粘剂预聚体的研制

以聚四氢呋喃二醇(PTMG)和二苯基甲烷4,4′-二异氰酸酯(MD I)为主要原料合成湿固型预聚体,研究了湿固型预聚体的制备条件。结果表明,预聚反应的最佳温度为80℃左右,最佳反应时间为2 h,预聚体中-NCO质量分数为3%时,预聚体的稳定性、可操作性能最佳。     

Effects of soft segments on the surface properties of polydimethylsiloxane waterborne polyurethane prepolymer blends and treated nylon fabrics

This study of waterborne polyurethane prepolymer blends was done to investigate the effects of different types of soft segments on the dispersion properties and other properties of treated nylon fabrics. The particle size of the dispersion increased, the surface tension of the dispersion decreased, and the contact angle of the nylon fabric with the dispersion decreased when the blending amount of the polydimethylsiloxane polyurethane prepolymer increased. The add‐on of ether‐type polyurethane increased rapidly when the ether‐type polyurethane was blended with a small amount of the polydimethylsiloxane polyurethane prepolymer, whereas the add‐on of the ether‐type polyurethane reached a maximum at a blending content of 10%. The add‐on of the ester‐type polyurethane prepolymer constantly decreased with increasing blending amount of the polydimethylsiloxane polyurethane prepolymer. The vertical wicking height of the treated nylon fabrics decreased slightly when the treating agent contained a small amount of the polydimethylsiloxane polyurethane prepolymer. For the treated nylon fabrics with blended prepolymers, the drying time was faster than for the untreated fabric, and the moisture ratio reached about 10% in 15 min © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

端异氰酸酯基聚氨酯预聚体的合成与表征

以异佛尔酮二异氰酸酯(IPDI)和聚乙二醇2000(PEG2000)为单体,在二月桂酸二丁基锡(DBTDL)的催化作用下,通过逐步聚合反应合成了NCO封端的聚氨酯预聚体(PPU).通过单因素实验分析法优化出了PPU合成条件:反应温度70℃,w(DBTDL)=0.75%(以IPDI和PEG2000的总质量计),反应时间为1.5 h.利用FT-IR、1H-NMR等方法对单体和PPU的分子结构进行了表征,通过综合热分析测试了PPU的热分解温度T_g为268.2℃.     

Toughening of epoxy resin using synthesized polyurethane prepolymer based on hydroxyl-terminated polyesters

Epoxy resins are increasingly finding applications in the field of structural engineering. A wide variety of epoxy resins are available, and some of them are characterized by a relatively low toughness. One approach to improve epoxy resin toughness includes the addition of either a rigid phase or a rubbery phase. A more recent approach to toughen brittle polymers is through interpenetrating network (IPN) grafting. It has been found that the mechanical properties of polymer materials with an IPN structure are fairly superior to those of ordinary polymers. Therefore, the present work deals with epoxy resin toughening using a polyurethane (PU) prepolymer as modifier via IPN grafting. For this purpose, a PU prepolymer based on hydroxyl-terminated polyester has been synthesized and used as a modifier at different concentrations. First, the PU-based hydroxyl-terminated polyester has been characterized. Next, an IPN (Epoxy–PU) has been prepared and characterized using Fourier transform infrared (FTIR) spectroscopy, thin-layer chromatography (TLC), and scanning electron microscopy (SEM) prior to mechanical testing in terms of impact strength and toughness. In this study, a Desmophen 1200-based PU prepolymer was used as a modifier at different concentrations within the epoxy resin. The results also showed that, further to the IPN formation, the epoxy and the PU prepolymer reacted chemically (via grafting). Compared to virgin resin, the effect on the mechanical properties was minor. The impact strength varies from 3–9 J/m and K_c from 0.9–1.2 MPa m^1/2. Furthermore, the incorporation of a chain extender with the PU prepolymer as a modifier into the mixture caused a drastic improvement in toughness. The impact strength increases continuously and reaches a maximum value (seven-fold that of virgin resin) at a modifier critical concentration (40 phr). K_c reaches 2.5 MPa m^1/2 compared to 0.9 MPa m^1/2 of the virgin resin. Finally, the SEM analysis results suggested that internal cavitation of the modifier particles followed by localized plastics shear yielding is probably the prevailing toughening mechanism for the epoxy resin considered in the present study. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 70: 2603–2618, 1998     

有机硅烷偶联剂改性紫外光固化超支化聚醚基水性聚氨酯的性能

采用超支化聚酯Boltorn H 20与丁二酸酐反应,制备了亲水性超支化聚酯,然后与甲基丙烯酸酯基改性的聚醚基聚氨酯预聚体和3-异氰酸酯基丙基三乙氧基硅烷(IPTS)反应,合成了有机硅烷偶联剂改性紫外光固化聚醚基超支化水性聚氨酯(WHPU)。考察了有机硅烷偶联剂用量对WHPU的耐酸性、固化时间、凝胶质量分数、附着力、水接触角、水吸附率、乳液粒径分布及热稳定性的影响。结果表明,当IPTS与Boltorn H 20中羟基的摩尔比为6/16时,固化后的WHPU膜的凝胶质量分数为92%,在玻璃表面的附着力达到0级;与不含有机硅烷偶联剂的WHPU相比,该涂膜的水接触角和热稳定性分别提高了34°和22℃,其吸水率从13.8%降低到4.3%。     

聚氨酯型光敏树脂预聚体合成进展

本文介绍了聚氨酯型光敏树脂预聚体的各种结构类型及合成方法，并简要说明了各类预聚体的基本性能和用途。