支化结构不饱和聚酯的合成及性能研究

以乙二醇、季戊四醇(丙三醇)、反丁烯二酸为原料合成了含支化结构的不饱和聚酯(RP),对产物进行了红外表征,并通过GPC、DSC和TGA测试对其性能进行了研究。结果表明,季戊四醇(丙三醇)用量为反丁烯二酸物质的量的5%为宜,最佳反应温度为190～200℃,RP树脂数均分子质量为线形UP树脂的5倍左右。RP树脂相比UP树脂固化快,其最大放热温度、热稳定性和冲击性能均有所提高,其中冲击强度提高33%。此外,丙三醇型RP树脂较季戊四醇型反应易于控制,反应程度高。     

TBPB/TBPO引发不饱和聚酯树脂固化特性研究

本文采用DSC法研究TBPB/TBPO引发不饱和聚酯体系的固化行为,比较TBPO百分含量变化对于该体系固化反应的影响。通过DSC、树脂反应活性分析仪研究TBPB/TBPO引发不饱和聚酯体系固化反应温度、凝胶时间和固化时间。研究结果表明,随着TBPO百分含量从10%增加到100%,固化反应峰值温度由142℃降低到120.8℃,凝胶时间由214s降为79.5s,固化时间由634.5s缩短为171.5s。     

二甲苯不饱和聚酯树脂的结构对其性能的影响

一、引 言 二甲苯不饱和聚酯树脂是以二甲苯甲醛树脂和顺丁烯二酸反应制成不饱和聚酯,再以苯乙烯作交联剂制成的产物。它以低粘度、低收缩率、耐酸、耐碱、高频绝缘等性能为特色。我们曾发表了二甲苯不饱和聚酯树脂合成与基本性能的研究结果,本文介绍二甲苯甲醛树脂,双键和酯键含量对不饱和聚酯树脂的固化活性、固化程度、体积收缩率、玻璃化温度、热     

双环戊二烯改性不饱和聚酯锚固剂的研究

探讨了不饱和聚酯锚固剂的合成方法:将顺丁烯二酸酐和双环戊二烯加入反应器中,在80～120℃条件下滴加与双环戊二烯等摩尔的水,反应2 5h;再加入其它成分,升温酯化直至反应完全。双环戊二烯的含量影响不饱和聚酯同苯乙烯的混溶性和固化过程。双环戊二烯改性不饱和聚酯树脂与标准树脂相比较,粘度小,填充量大,固化快,机械强度高,空干性好,具有一定的经济效益。     

无苯乙烯乙烯基酯树脂的合成及性能研究

采用丙氧基化双酚A(D33单体)、邻苯二甲酸酐、顺丁烯二酸酐、二苯基甲烷二异氰酸酯、甲基丙烯酸羟丙酯合成了一种不含苯乙烯的环保型丙烯酸/聚氨酯/不饱和聚酯三元共聚树脂。将该树脂基体的性能:酸值、粘度、固体含量、80℃热稳定性及25℃凝胶时间,树脂浇注体的的力学性能及其FRP板材的气干性与传统双酚A型乙烯基酯树脂MFE 711进行了对比,并测试了树脂的VOC含量。结果表明,该树脂的VOC含量为104.97 g/L,远低于有害物质规定限值,并且具有与通用乙烯基酯树脂相当的液体树脂性能和力学性能,可用于光固化、手糊、喷射、缠绕、拉挤、原位固化法(CIPP)等成型工艺。     

UV固化超支化聚酯的合成及性能研究

以马来海松酸(MPA),环氧氯丙烷(ECH)合成了超支化聚酯(HBPE),通过丙烯酸羟乙酯(HEA)对HBPE改性合成了涂料可用UV固化超支化聚酯。采用GPC,FT-IR,DSC等对产物结构进行了表征,研究了原料配比、加料方式和反应温度等对产物的影响,并考察了其光固化行为,测试了固化膜的性能。结果表明,HBPE合成最佳条件:n(MPA)∶n(ECH)=1∶1,反应温度90℃,HBPE与HEA最佳物质的量比为1∶2。该UV固化超支化聚酯固化膜附着力1级,抗冲击力40 kg/cm,铅笔硬度4H,耐甲乙酮100,可作为UV固化涂料中的主体树脂。     

不饱和聚酯片状模塑料的研究

采用聚氨酯预聚物作增稠剂对带端羟基的不饱和聚酯进行增稠,制备出一种新型的不饱和聚酯片状模塑料(SMC),并研究了其增稠性能、增韧性能及贮存稳定性。结果表明,增稠剂PU400的用量要控制在8％～10％,否则树脂糊无法正常浸渍玻璃纤维;不饱和聚酯SMC的体积收缩率随PU400加入量的增加而明显变小;当PU400含量为36％,时,不饱和聚酯SMC固化物的拉伸强度、断裂伸长率、冲击强度都维持在一个较高的水平;该不饱和聚酯SMC有良好的贮存稳定性。     

光敏不饱和聚酯(UPR)的合成研究

采用熔融法制备了可紫外光固化的光敏不饱和聚酯(UPR),研究了UPR反应的酸值与反应时间的关系及醇酸比对UPR玻璃化转变温度的影响,还讨论了反应温度等因素对光敏不饱和聚酯合成反应的影响,最终得到反应的优惠工艺条件。     

不饱和聚酯聚氨酯纳米复合材料的研究

采用混合二元醇、二元酸通过缩聚反应合成不饱和聚酯树脂(UPR),UPR与甲苯二异氰酸酯(TDI)经逐步加聚得到不饱和聚酯型聚氨酯树脂(UPPU),UPPU与γ-缩水甘油醚氧丙基三甲氧基硅烷(KH560)改性的纳米凹凸棒土复合得到不饱和聚酯型聚氨酯纳米凹凸棒复合材料。通过SEM、FT-IR、TG等方法对不饱和聚酯聚氨酯纳米复合材料进行了表征。结果表明,当KH-560用量及改性纳米凹凸棒土用量为UPPU质量的2%时,纳米复合材料的热稳定性和韧性有了很大的提高。     

含硅氢基团甲基芳炔树脂的合成及表征

以二氯甲基硅烷和间二乙炔基苯为原料,通过格氏反应合成了不同分子量的含硅氢基团甲基芳炔树脂(PSA-H),并分析确定了合成产物的结构. 树脂的热固化行为和固化树脂的热稳定性分析表明,PSA-H树脂具有良好的加工性能,可在较低的温度下(低于200℃)发生交联反应. 其固化物有较低的介电常数(2.57 F/m)、较低的介电损耗(tand 0.001)和优异的热稳定性,在N2气氛下5%失重温度Td5为675~703℃, 1000℃的残留率为90.9%~91.4%. PSA-H树脂固化物在氩气中1450℃下烧结可形成含b-SiC陶瓷.     

Study of the behavior of polyester concretes containing ionomers as curing agents

Polyester concretes have been used in constructions for more than 20 years. This type of polymer concrete can advantageously replace traditional Portland concrete in situations that require fast consolidation of the material. Otherwise, polyester concretes are usually more expensive than Portland concretes. Part of the high cost of the polyester concretes is due to the fact that the aggregates used in the formulation of the concretes need to be dried prior to their incorporation into the polymer matrix. In this work, the use of different curing systems (methacrylic acid and maleic anhydride) was investigated to test the hypothesis that the introduction of acid functionalities into unsaturated polyesters based on isophthalic acid could both restrict the detrimental effect of moisture in the curing process and also improve interfacial interactions even in polyester concretes containing wet aggregates. In this work, as there was no search for ways to reduce cost of polyester concretes and also to contribute to the environmental preservation, unsaturated polyesters were synthesized from PET bottles and tested in the fabrication of concretes by reacting them with a conventional curing agent (styrene). Gel permeation chromatography, infrared spectroscopy, and electron microscopy were used to monitor and analyze the production of unsaturated polyester resins and concretes. Mechanical properties were also evaluated by compression tests. Results showed that methacrylic acid and maleic anhydride, when used as curing agents, led to the production of polyester concretes having higher mechanical properties in both dry and wet states than conventional polyester (based on isophthalic acid) concretes. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Photocuring of a thiol‐ene system based on an unsaturated polyester

To produce a photocurable thiol‐ene system, unsaturated polyester was prepared from the condensation reaction of ethylene glycol, diethylene glycol, and fumaric acid. Diallyl groups were introduced into the ends of the unsaturated polyester by a sequential condensation reaction. The coating formulation studied contained an equimolar ratio of thiol and vinyl groups of the prepared unsaturated polyester, including 1 wt % Irgacure 184. The curing behaviors of the unsaturated polyester with multifunctional thiols were investigated using real‐time FTIR spectroscopy. The rates of disappearance of thiol and vinyl groups of the unsaturated polyester were similar, demonstrating that there was little free‐radical homopolymerization of the internal fumaric group or the end‐capped vinyl ether group during the photocuring process and that the thiol‐ene reaction is the dominant process. The kinetics of the model compounds demonstrated that the reaction of the terminal allyl double bond with the thiyl radical is faster than that of the internal fumaric double bond in the UV curing of the unsaturated polyester. The storage stability of the thiol‐ene system based on unsaturated polyester was effectively increased by the addition of N‐PAL. The Raman spectra revealed that the presence of a multifunctional thiol (penta 3‐MP4) in the coating formulation increased the degree of surface curing due to the chain‐transfer ability of the thiyl radical. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 342–350, 2005     

Curable resins based on recycled poly(ethylene terephthalate) for coating applications

Poly(ethylene terephthalate) waste was depolymerised in the presence of diethylene- or tetraethylene glycol and manganese acetate as a catalyst. An epoxy resin was then prepared by the reaction of these oligomers with epichlorohydrin in presence of NaOH as a catalyst. The produced oligomers were condensed with maleic anhydride and ethylene glycol to produce unsaturated polyester. The chemical structures of the resulting epoxy and unsaturated polyester resins were confirmed by ¹HNMR. The vinyl ester resins were used as cross-linking agents for unsaturated polyester resin diluted with styrene, using free radical initiator and accelerator. The 2-amino ethyl piprazine was used as hardener for epoxy resins. The curing behaviour of the unsaturated polyester resin, vinyl ester resins and styrene was evaluated at different temperatures ranged from 25 to 55 °C to calculate the curing activation energy of the system. The cured epoxy and unsaturated polyester resins were evaluated in coating application of steel.     

Graphite Nanosheet as Low Shrinkage Additive,Curing Accelerator,and Conducting Filler for Unsaturated Polyester Resin

The effect of graphite nanosheets on electrical properties, curing behavior, and polymerization shrinkage of unsaturated polyester resin has been investigated. A solution of polystyrene was used as low profile additive to reduce shrinkage. The results showed that graphite nanosheets have been well dispersed/distributed in the unsaturated polyester matrix where they have high aspect ratio and high surface area. Graphite nanosheet exhibited an accelerating effect on the curing of unsaturated polyester and reduced the polymerization shrinkage as low as 3.6%. Despite large reduction of flexural properties by low profile additive, graphite nanosheet considerably increased the flexural strength and modulus of unsaturated polyester/low profile additive by 47 and 103%, respectively. Therefore, graphite nanosheet can be used as a new low profile additive for unsaturated polyester resins where it is also able to improve mechanical properties and curing rate.     

不饱和聚酯树脂微乳液的快速固化研究

探讨了过氧化物 (过氧化甲乙酮、过氧化氢、叔丁基过氧化氢、异丙苯过氧化氢 ) /抗坏血酸组成的氧化 -还原引发聚合体系对磺酸盐不饱和聚酯树脂及其油包水型微乳液的固化特性。结果表明 :磺酸盐不饱和聚酯树脂的凝胶时间和固化时间都比相应的微乳液长。 4种过氧化物中 ,过氧化氢的常温引发聚合反应最快 ,能使微乳液 30s内凝胶 ,7min内固化 ,达到了快速固化的目的     

Effect of particulates and fiber reinforcements on the curing behavior of unsaturated polyester resin

The effect of particulates and reinforcement on the curing behavior of unsaturated polyester resin was investigated. Also investigated was the effect of surface treatment of particulates on the curing behavior of unsaturated polyester resin. We have found that (1) an increase in the surface area, by either increasing the loading of particulates for a fixed particle size or decreasing the size of particulates for a fixed loading of particulates, enhanced the rate of cure, and (2) the treatment of glass beads with γ-methacryloxy propyltrimethoxy silane enhanced the rate of cure of unsaturated polyester resin.     

Microgelation in the curing reaction of unsaturated polyester resins

A series of unsaturated polyesters were synthesized with various chemical structures and molecular weights. These unsaturated polyesters were used to study the curing reaction with styrene by using gel permeation chromatography and differential scanning calorimetry. The variation of the size of microgel particles during the curing reaction in unsaturated polyester–styrene resins was studied by using gel permeation chromatography. The size and structure of the microgels depend strongly on the polymer chain length and the number of vinyl groups on each unsaturated polyester chain. Using the differential scanning calorimetric method, the conversion of styrene and polyester vinyl groups during the reaction was measured. The experimental results of this study revealed that microgel formation has a great effect on the curing reaction of unsaturated polyester resins. © 1994 John Wiley & Sons, Inc.     

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。     

Toughened polyester matrices for advanced composites

An intercrosslinked network of hybrid bismaleimide (BMI) modified vinyl ester oligomer–unsaturated polyester matrix systems have been developed. Vinyl ester oligomer (VEO) was used as a toughening agent for unsaturated polyester resin and was added in 2, 4, and 6% (by wt). Benzoyl peroxide was used as curing agent. The VEO‐toughened unsaturated polyester matrix systems were further modified with 5, 10, and 15% (by wt) of bismaleimide. Bismaleimides modified vinyl ester–unsaturated polyester matrices were characterized by mechanical (tensile strength, flexural strength, tensile modulus, flexural modulus, and impact strength), thermal [differential scanning calorimetry (DSC), thermogravimetic analysis (TGA), heat deflection temperature analysis (HDT)] and morphological studies [scanning electron microscope (SEM)] and water absorption. Data obtained from mechanical studies indicated that the introduction of VEO into unsaturated polyester resin improves the fracture toughness. The introduction of BMI into VEO incorporated unsaturated polyester resin enhanced both thermal and mechanical behavior. The scanning electron micrographs of fractured surfaces of VEO‐modified unsaturated polyester systems and BMI modified vinyl ester–unsaturated polyester matrices illustrate the presence of homogeneous morphology. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 167–177, 2007