Crosslinking of unsaturated polyester resins studied by low-resolution 1H-NMR spectroscopy

The curing behavior of five unsaturated polyester resins with different molar ratios of styrene to the double bonds in the polyester chain (MR) was investigated. The gel time was measured according to a standard method by the Society of the Plastic Industry (SPI) and by low-resolution pulse nuclear magnetic resonance (LRP-NMR). The gel and curing times decreased and the maximum temperature of the reaction increased when the MR was decreased. The proton mobilities and populations were measured by LRP-NMR. Three components could be seen in the crosslinking reaction: styrene (very mobile, T₂ ≅ 3 s), free polyester polymers (less mobile, T₂ ≅ 150 ms), and cured resin (immobile, T₂ ≅ 0.04 ms). The third component, cured resin, could be detected at the gel point. At this point, the proton mobilities of styrene and free polyester polymers were rapidly decreasing and the proton populations of the cured resin started to increase. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 77–83, 1997     

影响涂料用DCPD型不饱和聚酯涂料凝胶时间的因素

主要从不饱和聚酯树脂酸值,苯乙烯、促进剂、引发剂的用量,颜填料的选择与用量等方面进行了研究,考察这些因素对气干性DCPD型不饱和聚酯涂料凝胶时间的影响,为不饱和聚酯涂料的实际生产和应用提供参考。     

不饱和脂肪族聚酯生物降解性的研究

以1,4-反丁烯二酸和一缩二乙二醇（DEG）为原料,采用缩聚法合成端羟基不饱和聚酯,并采用红外光谱分析（FT—IR）、羟值、酸值、黏度等对所得聚合物进行表征,确认了其分子结构．对其降解性进行研究,并且与1,4-丁二酸与一缩二乙二醇合成的饱和脂肪族聚酯进行了对比。研究结果表明,不饱和脂肪族聚酯和饱和脂肪族聚酯的生物降解性差别不大,也就是双键的引入对其生物降解性没有大的影响;但是不饱和脂肪族聚酯膜经过高温处理后,双键会打开发生交联,而交联后的不饱和脂肪族聚酯的生物降解性变差,而且交联度越高,生物降解性越差。     

Bis(nitrone) as crosslinking agent for unsaturated polyesters via 1,3‐dipolaric cycloaddition

The microwave‐assisted polycondensation of maleic anhydride and 1,6‐hexanediol was carried out using p‐toluenesulfonic acid as catalyst. The resulting unsaturated polyester was characterized using Fourier transform infrared (FTIR) and ¹H NMR spectroscopy, and the molecular weight determined using gel permeation chromatography. 4,4′‐Decanediyldioxydi(N‐methyl‐p‐phenylenenitrone) was chosen as a model compound for the crosslinking of the unsaturated polyester. The crosslinking, which is known to proceed via 1,3‐dipolaric cycloaddition, was followed using differential scanning calorimetry. Additionally, the kinetics of the cycloaddition was evaluated at 120 °C using FTIR spectroscopy. Copyright © 2012 Society of Chemical Industry     

Cross-linkers control the viscoelastic properties of soybean oil-based biomaterials

Because of environmental concerns, biodegradable materials have been of increasing research interest over the last several years. Previously, we reported on a biobased material developed from epoxidized soybean oil (ESO) that displayed viscoelastic behavior similar to synthetic rubbers or plastics. In this work, the viscoelastic properties of several biomaterials made from ESO cross-linked by different amounts of two different cross-linking agents were investigated. The composites exhibited different glass transition temperatures and viscoelastic behaviors depending on the type and amount of cross-linker used. Higher glass transition temperatures and stronger viscoelastic properties of the materials were found with a greater amount of cross-linker. Comparing agent triethylene glycol diamine (TGD) with agent triethylenetriamine (TETA), we found that the material cross-linked by TETA had a higher glass transition temperature and stronger viscoelastic solid properties than the material cross-linked by the agent TGD.     

苯乙烯对不饱和聚酯树脂性能的影响

本文主要探讨了不饱和聚酯中应用得最广泛的活性稀释剂——苯乙烯，对不饱和聚酯树脂机械性能、电性能、吸水性、耐化学性等的影响，从而为实际生产中采用最佳的苯乙烯含量提供参考。     

含水不饱和聚酯的动态流变行为和微观结构

使用三乙醇胺(TEA)和Span80复合乳化剂制备含水不饱和聚酯树脂,改变水/乳化剂的比率(W/E)和TEA∶Span80复合比例,通过动态流变法研究含水不饱和聚酯树脂乳液的流变性质,结合光学显微镜和SEM扫描电镜分析微观结构,并测试固化树脂材料的力学性能。实验表明在一定含水量和乳化剂复合比例下,可以制备出乳胶粒子界面膜强度高,粒子数密度高,分布均匀,且乳液稳定性好的含水不饱和聚酯(WCUP)树脂,得到力学强度高的固化树脂,并得到了复合乳液黏度随应力和频率的流变规律。最佳配比TEA∶Span80=9.0∶1.0,W/E=19.2时,其树脂固化体系的拉伸强度和冲击强度比单使用TEA体系分别提高了34%和67%。     

Modification of unsaturated polyester resin with bismaleimide

The modification of a commercially available unsaturated polyester resin with 4,4′‐bismaleimidodiphenylmethane is presented. The properties of the modified resins were compared with those of the nonmodified resin, and the resins were characterized in the noncured state and after curing. The results indicate that the addition of bismaleimide to unsaturated polyester resin not only improves its properties but also accelerates the curing reactions. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2003–2007, 2001     

不饱和聚酯型人造大理石的力学性能

简述了不饱和聚酯(UPR)型人造大理石的制备工艺。研究了质量比为4∶1的Al(OH)3/Ca(OH)2复合填料用量对不饱和聚酯型人造大理石力学性能的影响,对制得的人造大理石的耐腐蚀性进行了测试,采用光学显微镜观察了试样腐蚀前后的表面形貌。结果表明,在复合填料与UPR质量比为1.86∶1时,弯曲强度、压缩强度达到最大,分别为55.88 MPa和96.04 MPa。甲苯对人造石的腐蚀作用最大,氢氧化钠次之,硫酸腐蚀作用较小,腐蚀介质主要对不饱和树脂聚合物产生腐蚀,从而导致人造石力学性能降低。     

Influence of TDI concentration on the properties of unsaturated polyester resins

Three different unsaturated polyester resins were modified by toluene diisocyanate (TDI). All the resins studied were commercially available. One, 2, and 3% additions of TDI caused important changes of the resins properties. With an increase of TDI concentration gelation times increased. Suppression of the exotherm peaks—desired effect from practical point of view—was observed. Unfortunately, increase of TDI concentration caused enormous increase of the resins viscosity. Additionally the resins with 3% of TDI exhibit thixotropic properties. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 1201–1206, 2001     

Modification of unsaturated polyesters by poly(ethylene glycol) end groups

This article reports on the modification of unsaturated polyesters by poly(ethylene glycol) end groups in order to influence the solution behavior in styrene and to modify mechanical properties of the cured resin. The synthesis was done by the reaction of a carboxyl-terminated unsaturated polyester with various poly(ethylene glycol) mono-methyl ethers of molecular weights from 350 to 2000 g/mol. The characterization and curing properties of the synthesized block copolymers are presented. The glass transition temperatures decrease with increasing length of the poly(ethylene glycol) end groups. The introduction of long poly(ethylene glycol) end groups (2000 g/mol) leads to a phase separated and partly crystalline block copolymer with a melting point of 48°C. The block copolymers can be easily diluted in styrene to create the curable resins. The mixtures containing the block copolymers with the short poly(ethylene glycol) end groups (350 and 550 g/mol) could be cured in a reasonably short time. Compared to commercial unsaturated polyesters the mechanical testing revealed that the tensile strength is decreasing while the elongation is increasing. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 527–537, 1997     

Synthesis and properties of unsaturated epoxyfumarate resins

Synthesis and properties of epoxyfumarate and epoxymaleate resins obtained by the addition of acidic ester of maleic acid to the commercially available resin, Epidian 5, is presented. In acidic ester preparation, n‐hexanol was used. The resins were synthesized in one‐ and two‐step procedures. In the two‐step procedure, acidic hexyl maleate was synthesized separately and then used for the addition reaction with epoxy resin. In the one‐step synthesis, acidic ester was formed during the synthesis process. Properties of the obtained resins were compared. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 3077–3084, 2000     

环保型MES粘弹性胶束溶液的流变性

用流变学方法研究了可生物降解阴离子表面活性剂脂肪酸甲酯磺酸钠（MES）在NaCl溶液中从球状胶束转变成蠕虫状胶束的生长过程,分析了两性表面活性剂十二烷基甜菜碱（BS-12）对MES胶束溶液流变行为的影响机制。首先,测量了MES粘弹性胶束体系剪切粘度（η）和剪切速率的关系,得到零剪切粘度（η0）;然后由动态振荡实验,得到复合粘度｜η＊｜、动态模量（储能模量G＇、损耗模量G″和结构松弛时间τs）等物理量;应用Cox-Merz规则和Cole-Cole图,证实了MES（3.0%～5.0%）/NaCl（3.0%～5.0%）/BS-12（0.5%～0.9%）体系形成蠕虫状胶束,且蠕虫状胶束的动态粘弹性在MES（3.5%～5.0%）/NaCl（3.5%～5.0%）/BS-12（0.5%～0.9%）范围是符合Maxwell模型的线性粘弹性流体。     

不饱和聚酯树脂微波固化特性研究

探讨了UPR在微波加热作用下固化的可行性及特性规律,采用DSC及FTIR等手段对微波加热固化及传统加热树脂固化性能进行了分析,结果显示微波加热凝胶固化时间比后者快几倍至20多倍,热性能、力学性能基本相当,这表明微波加热固化UPR可行且高效。     

对苯型不饱和聚酯树脂性能的研究

研究了以聚酯回收料为原料生产的对苯型不饱和聚酯树脂的固化性能和耐化学腐蚀性能,分析了影响凝胶时间的各种因素。试验结果表明,所得对苯型树脂具有优良的耐化学腐蚀性能。其耐酸性、耐碱性、耐盐性和耐水性能与间苯UPR树脂相当,其耐溶剂和耐氧化酸性能与双酚A型UPR树脂相当。     

桦木纤维/不饱和聚酯复合材料制备与性能研究

采用硅烷偶联剂、乙醇和水等分别对桦木纤维(BF)和回收纸浆纤维进行表面处理,并分别将改性纤维作为不饱和聚酯树脂(UPR)的增强材料,制备相应的BF/UPR复合材料。研究了不同改性方法对复合材料界面性能的影响。结果表明:不同纤维种类、不同纤维表面处理方法和不同纤维用量对复合材料的界面性能、力学性能等影响较大;经硅烷偶联剂处理后的BF,可有效改善BF与UPR之间的界面相容性;当w(偶联剂处理BF)=16%时,相应复合材料的拉伸强度和冲击强度比纯UPR体系分别提高了31.0%和28.5%;在制备回收纤维/UPR复合材料之前应先对回收材料进行筛选,并且应优先选择对UPR基体树脂具有明显增强作用的回收纤维。     

豆油制备不饱和聚酯树脂性能研究

以可再生资源豆油、丙三醇为原料醇解制备了单甘酯,将其作为二元醇,部分取代丙二醇与酸酐反应制得不饱和聚酯树脂(UP)。采用DSC,DMA以及力学性能测试等手段研究了单甘酯含量对豆油不饱和聚酯树脂性能的影响。结果表明,随着单甘酯含量的增加,豆油不饱和聚酯树脂的固化放热峰值降低、固化收缩率减小;存储模量和玻璃化转变温度都有一定程度降低,弯曲强度和拉伸强度也逐渐下降;冲击强度和拉伸断裂伸长率增高(单甘酯质量分数为40%时可分别达到102.074 kJ/m2和27.69%)。该方法制备的UP树脂成本低廉,柔韧性好,可满足一般的使用要求。     

Synthesis and properties of UV-curable waterborne unsaturated polyester for wood coating

UV-curable waterborne unsaturated polyesters for wood coatings were prepared. The effects of different polyols and acids on the properties of the UV-curable waterborne unsaturated polyesters were investigated. Several different unsaturated polyester prepolymers were prepared from three different polyols [ethylene glycol (EG), diethylene glycol (DEG), and propylene glycol (PG)] and three different acids [tetrahydrophthalic anhydride (THPAn), terephthalic acid (TPA), and trimellic anhydride (TMAn)]. UV-curable coating materials were formulated from the prepolymers and 2-hydroxy-2-methylphenyolpropane-1-one as a photoinitiator with distilled water as a diluent. Trimethylolpropane diallyl ether was used as an air inhibitor of cure. The dynamic mechanical studies showed the properties of those unsaturated polyesters were well correlated with their glass transition temperature behaviors. It was found that the unsaturated polyester prepared with 60/40 (mol %) TMAn/THPAn and the equimolar mixture of EG, DEG, and PG showed balanced coating properties such as good tensile properties and weatherability, as well as proper viscosity (ca. 2500 cps) when using distilled water as a diluent. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 695–708, 1998     

利用废聚酯制备对苯型不饱和聚酯树脂的研究

介绍了利用废聚酯制备对苯型不饱和聚酯树酯的方法。研究表明,该工艺简单合理,产品的耐腐蚀性、耐热性、机械性能和电性能优良     

不同纳米粒子改性不饱和聚酯树脂的对比研究

分别采用纳米二氧化硅、纳米蒙脱土及其复配体系改性不饱和聚酯树脂(UPR),对比研究了不同样品的弯曲性能、冲击性能及吸水性能。结果表明:纳米蒙脱土质量分数为3%的样品的弯曲强度及冲击强度均明显低于含纳米二氧化硅的样品,但模量值却正好相反。选用2种纳米粒子按不同比例复配后,可使UPR弯曲模量及冲击强度得到进一步提高,但对弯曲强度无积极效果。温度对吸水率及吸水平衡存在显著影响,升高温度,所有样品的吸水率急剧增大,更加不容易达到吸水平衡。