共查询到17条相似文献,搜索用时 146 毫秒
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过氧化甲乙酮是不饱和聚酯和乙烯基酯树脂的主要引发剂,它由几种不同结构的有机过氧化物组成,其中两种结构的有机过氧化物对聚酯树脂和乙烯基酯树脂的凝胶和固化起决定作用,过氧化氢的存在将影响这种作用。 相似文献
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低收缩添加剂对聚酯树脂固化的影响 总被引:2,自引:0,他引:2
本文采用SPI法测定加入不同含量低收缩添加剂(LPA)的不饱和聚酯树脂的固化放热曲线。研究了低收缩添加剂的用量,以及中低温固化体系对不饱和聚酯树脂的凝胶时间,固化时间,放热峰温度,固化放热量的影响。 相似文献
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不饱和聚酯树脂室温固化引发剂体系 总被引:2,自引:0,他引:2
<正>不饱和聚酯树脂的固化是遵循游离基(共)聚合反应原理.游离基(共)聚合反应,除用加热、光照(紫外光)或高能射线(X、γ射线等)辐照引发外,绝大多数都是在引发剂的存在下实现的.引发剂的作用在于受热后分解产生游离基,游离基与不饱和聚酯及不饱和单体(交联剂)作用以引发(共)聚合反应.目前,不饱和聚酯树脂固化用的引发剂主要是有机过氧化物.这些有机过氧化物的分解活化能一般在25—40千卡/摩尔之间,临界温度在60℃以上,对于固化温度要求在 相似文献
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聚酯磺酸盐的合成及其乳液的研究(Ⅰ) 总被引:1,自引:0,他引:1
本文采用不饱和聚酯的磺化和带磺酸基的单体缩聚两种方法合成了系列聚酯磺酸盐,同时制备了较为稳定的 W/O型不饱和聚酯树脂乳液。讨论了相转移催化剂、缩聚反应催化剂等多种工艺条件对聚酯磺酸盐合成的影响。此外,本文还探讨了聚酯磺酸盐的种类、含量对亲水性、电导率、乳液稳定性的影响。 相似文献
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本文系统地介绍了不饱和聚酯树脂固化引发剂的基本原理、重要性质和新的进展。在纤维增强塑料(FRP)的手糊成型中,最常用的引发剂是酮过氧化物,它们与促进剂组成氧化还原引发体系,可使聚酯粘结剂在室温下凝胶、固化。促进剂加速有机过氧化物的分解,但过量促进剂对固化不利。对用于加热固化的聚酯粘结剂(如SMC),选择引发剂的主要依据为储存期。通常选用半衰期为10小时的、分解温度比成型温度高40℃的有机过氧化物为引发剂是合适的。为了防止固化制品开裂和翘曲,选用高浓度的低温引发剂或混合型引发剂是可取的。在SMC工艺中,使用过氧化缩酮作引发剂要比目前通用的过氧化酯有更多的优点。 相似文献
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Synthesis and properties of new initiating systems formed from commercially available ketones, glycols, and hydrogen peroxide (60%) are presented. In preparation of free radical initiators methyl ethyl ketone, which was oxidized by hydrogen peroxide, was used. Reaction was carried out in etanodiol or 1,4‐butanodiol as diluent. The obtained initiators with cobalt octoate as a promotor were applied for crosslinking of the commercially available unsaturated polyester resin. Properties of the resin were compared with those obtained while it was hardened by the typical curing system containing methyl ethyl ketone hydroperoxide and cobalt octoate. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 2238–2243, 2003 相似文献
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Wayne D Cook Michelle Lau Mansour Mehrabi Katherine Dean Marcus Zipper 《Polymer International》2001,50(1):129-134
The curing behaviour of an unsaturated polyester resin has been studied by gel time and pseudo‐adiabatic exotherm measurements. The gel time corresponded closely with the initial rise in exotherm temperature. Incorporation of tert‐butyl catechol inhibitor increased the gel time in a linear fashion and the exotherm was similarly delayed. An increase in the concentrations of initiator (either methyl ethyl ketone peroxide or acetyl acetone peroxide) or cobalt octoate accelerator decreased the gel time in a reciprocal fashion and increased the rate of polymerization. These results are fitted to a theoretical model for inhibition and initiation. © 2001 Society of Chemical Industry 相似文献
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芳叔胺促进剂对锚固剂的固化 总被引:1,自引:0,他引:1
研究了过氧化物与芳叔胺N,N-二甲基苯胺(DMA)和N,N-二甲基对甲苯胺(DMT)组成的体系引发不饱和聚酯锚固剂的固化,两种促进剂的锚固力和压缩强度相当;室温下用过氧化苯甲酰作引发剂时,发现DMT反应效率是DMA的1 5~3 5倍,与实验结果一致,即DMT的凝胶时间和固化时间比DMA分别缩短2/3和62%以上,放热峰温度也比DMA的高;由此说明,DMT比DMA具有更大的低温反应活性。在不用2,4-二氯代过氧化苯甲酰条件下,过氧化苯甲酰和DMT组成的体系也能使锚固剂达到超快速固化;说明DMT适合作锚固剂的促进剂。 相似文献
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N-甲基-N-2-羟乙基对甲苯胺和过氧化物引发体系 总被引:1,自引:0,他引:1
研究了N,N 二甲基苯胺(DMA)和N 甲基 N 2 羟乙基对甲苯胺(MHPT)与过氧化物组成的引发体系对不饱和聚酯树脂(UPR)固化的影响。结果表明:在促进剂浓度相同时,MHPT的凝胶时间为DMA的1/4~1/7,固化时间为DMA的缩短50%~25%,放热峰温度和巴氏硬度比DMA的高;固化温度与凝胶时间曲线表明MH PT比DMA的反应活性更高。温度比较低时(5℃),2,4 二氯代过氧化二苯甲酰(DCBPO)和过氧化二苯甲酰(BPO)/DMA体系不能使树脂快速固化,而DCBPO和BPO/MHPT体系能使树脂快速固化。使用DSC对固化的树脂样品进行非等温扫描,结里显示玻璃化转变温度和固化程度比DMA的高。 相似文献
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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 相似文献
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An oligomeric compound (Pol-2A) has been synthesized by a Michael-type addition of N-phenyl piperazine to double bonds of the maleic units of a polyester resin. This compound was used as activator (with benzoyl peroxide) in the curing of unsaturated polyester resins and compared in its efficiency with N,N-dimethylaniline (DMA). Pol-2A showed actiator characteristics comparable to those of DMA, with a wider range of gel times, and similar mechanical properties of the end products, with the advantage of a severe lowering of diffusibility and related environmental toxicity. 相似文献