共查询到20条相似文献,搜索用时 171 毫秒
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以苯乙烯、丙烯酸丁IR,N-羟甲基丙烯酰胺、丙烯酰胺为原料,用聚乙烯醇(PVA)作为胶体保护剂,采用无皂乳液聚合方式,制备苯乙烯-丙烯酸酯树脂乳液.同时以HDI三聚体与聚乙二醇单甲醚500(MPEG 500)为主要原料制备水分散聚异氛酸酯交联剂.用苯乙烯一丙烯酸酯树脂乳液与亲水改性聚异氛酸酯复合,制备纸张表面施胶增强剂... 相似文献
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利用马来酸酐与丙烯酸羟乙酯生成的半酯(HEAMA),制备改性蓖麻油树脂(HEAMACO),从而在蓖麻油分子上引入更多的双键和极性基团。对合成过程及产物的分子结构进行了详细的表征。HEAMACO与苯乙烯(St)通过自由基共聚合可制得生物降解型泡沫塑料,其压缩性能明显高于单独用马来酸酐改性蓖麻油树脂(MACO)制得的泡沫塑料,归因于分子链中引入了较高含量的双键和极性基团提高了泡沫塑料的交联密度。通过改变稀释单体的含量可调节泡沫塑料的软硬程度,并改变泡沫塑料的生物降解性。 相似文献
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李洪娟 《中国新技术新产品》2014,(3):4-6
以环己烯与乙酸为原料,在大孔苯乙烯阳离子交换树脂D006的催化下,通过烯烃酯化反应合成乙酸环己酯。对合成条件进行优化,并考察了树脂催化剂的稳定性。得到较佳的工艺条件为:n(环己烯):n(乙酸)=1:3,反应温度90℃,树脂用量2%(相对于环己烯和乙酸总质量),反应时间5h,搅拌速率300r/min,环己烯转化率94.5%,乙酸环己酯收率83%。催化剂连续使用10次,乙酸环己酯选择性维持在94%左右。 相似文献
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采用悬浮聚合法合成了甲基丙烯酸正丁酯、甲基丙烯酸β羟乙酯二元共聚树脂,并用冻胶纺丝技术制备了纤维状共聚物树脂.研究了甲基丙烯酸β羟乙酯含量对树脂饱和吸油率以及充分溶胀后树脂剩余率的影响,分别利用傅立叶变换红外光谱(FT-IR)和动态热机械分析仪(DMA)对树脂的化学结构和动态力学性能进行了分析和讨论. 相似文献
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采用乳液聚合技术将丙烯酸丁酯(BA)和丁二烯(Bd)、苯乙烯(St)共聚制备P(BA-co-Bd-co-St)胶乳(简称丁苯酯),然后在丁苯酯乳胶粒子上接枝St和AN合成P(BA-co-Bd-co-St)-g-SAN接枝共聚物。将其与SAN树脂熔融共混制备P(BA-co-Bd-co-St)-g-SAN/SAN共混物,研究了丁苯酯胶乳的粒径和组成对共混物力学性能和形态结构的影响。结果发现,引入丁二烯大大提高了SAN共聚物的接枝率,改善了共混物的冲击韧性,随着丁苯酯胶乳粒径的增加,共混物的冲击强度呈现先增大后减小的趋势。形态研究表明,丁二烯的引入显著改善了橡胶粒子在SAN树脂中的分散状况,但当粒径较小时,橡胶粒子发生了聚集。 相似文献
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通过控制N,N,N′,N′-四缩水甘油基-4,4’-二氨基二苯甲烷(TGDDM)和丙烯酸(AA)的摩尔比(n(AA)/n(TGDDM)=1∶1、2∶1、3∶1、4∶1),合成了一系列多官能团端乙烯基酯基-环氧树脂(MVE-EPs)。采用端基分析、傅里叶变换红外光谱(FT-IR)分析了反应过程中环氧基和乙烯基酯基的变化规律。结果表明,反应体系中环氧基含量逐渐降低而乙烯基酯基含量逐渐升高,TGDDM的分子链上部分环氧基转化为乙烯基酯基,生成既含环氧基又含乙烯基酯基的MVE-EPs树脂。采用FT-IR、核磁共振氢谱(~1H-NMR)和凝胶渗透色谱(GPC)等测试表征了不同MVE-EPs树脂的结构。结果表明,随着原料配比中AA含量增加,MVE-EPs中乙烯基酯基含量逐渐增加,环氧基含量逐渐降低,MVE-EPs的相对分子质量逐渐升高,其中多官能团环氧乙烯基酯树脂(MVER)的数均相对分子质量(M_n)最大,MVE-EP 2的多分散性指数最大。 相似文献
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EVM基共混物的阻尼性能 总被引:2,自引:0,他引:2
选用双叔基过氧化异丙基苯(BIPB)作为硫化剂,采用动态粘弹谱仪(DMA)对乙烯-醋酸乙烯酯橡胶(EVM)/乙丙胶(EPDM)和EVM/丁腈胶(NBR)两种共混体系的阻尼性能进行了研究.考察了聚氯乙烯(PVC)、N-环己基-2-苯井噻唑次磺(CZ)以及过氧化二异丙苯(DCP)对EVM基共混物阻尼性能的影响.实验结果表明... 相似文献
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为改善高固含量高聚物黏结炸药(PBX)和丁羟推进剂的工艺性能,以低分子量的端羟基聚丁二烯(HTPB)、异佛尔酮二异氰酸酯(IPDI)为主要原料,选用一缩二乙二醇(DEG)为扩链剂,采用二步法制备了聚氨酯弹性体。研究了催化剂用量对浆料黏度的影响,固化参数R及扩链剂用量对HTPB聚氨酯弹性体力学性能的影响。试验结果表明,当催化剂质量分数为0.004%时,适用期可达5 h;R值为1.1,DEG羟基含量占反应总羟基量的60%时,聚氨酯弹性体力学性能较好,拉伸强度达7.60 MPa,断裂伸长率达540.21%。动态力学分析(DMA)测试结果显示,低分子量HTPB聚氨酯弹性体有两个明显的玻璃化转变温度,说明样品存在明显的微相分离结构。 相似文献
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Marta Worzakowska 《Journal of Materials Science》2009,44(15):4069-4077
The interpenetrating polymer networks (IPNs) were formed by unsaturated polyester resin (UPR) polymerized by free radical
initiators: benzoyl peroxide (BPO) or cumene hydroperoxide (CHP) and epoxy polyester (EP), cured with acid anhydrides: tetrahydrophthalic
anhydride (THPA) or maleic anhydride (MA). IPNs consisting 10, 30, 50, 70, 90 wt% of EP were prepared. The effect of the EP
component in the IPNs and the type of curing agent on the cure behavior, thermal, and viscoelastic properties have been investigated.
The results showed that both EP content and used curing system influenced on studied properties. As the EP content increased,
the glass transition temperatures (T
g) also increased. Moreover, higher values of tanδmax and lower values of cross-linking density in a rubbery state (νe) of IPNs containing higher EP content, probably due to plasticization effect of EP component were observed. Additionally,
more heterogeneous network structure (higher values of the full-width at half-maximum (FWHM) as the EP content decreased was
prepared. The thermal and viscoelastic properties of the blends cured with BPO/MA or CHP/MA system were considerably better
than those cured with BPO/THPA or CHP/THPA. The higher stiffness, νe, T
g and lower tanδmax values were obtained. It was probably connected with the interactions of carbon–carbon double bonds of MA with vinyl monomer
(styrene), UPR and radical initiators causing to obtain more cross-linked polymer network structure. This supposition was
confirmed on basis of the cure reaction monitored by DSC. The chemical interactions between two components of the blends and
epoxy hardener caused that the BPO/MA or CHP/MA cure systems influenced on the cure behavior of UPR and EP components in the
IPNs. The exotherm peak temperature (T
max1) shifted to lower values compared to these in the neat UPR whilst T
max2 shifted to higher values than in the neat EP. However, the cure behavior of the UPR was not greatly affected by the presence
of EP component when BPO/THPA or CHP/THPA cure systems were used due to the lack of chemical interactions between the components
and their curatives. 相似文献
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低粘度环氧树脂体系及其固化物性能的研究 总被引:1,自引:0,他引:1
为了满足环氧树脂在多种工艺中对低粘度的要求,使用了6002及618型两种普通双酚A型环氧树脂与低粘度XCT-802固化剂,设计出一种低粘度的环氧树脂体系,并对其粘度、固化物的力学性能等进行了表征。结果表明:该体系在常温下具有较长的适用期;在中温(80~C)条件下即可凝胶并固化,其固化物的力学性能优异。 相似文献
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Adjacency crosslinked polyurethane--urea (PUU) elastomers with different crosslinking density were prepared by using hydroxyl-terminated liquid butadiene-nitrile (HTBN), toluene diisocyanate (TDI) and chain extender 3,5-dimethyl thio-toluene diamine (DMTDA) as raw materials, dicumyl peroxide (DCP) as initiator, and N,N'-m-phenylene dimaleimide (HVA-2) as the crosslinking agent. The influences of the crosslinking density and temperature on the structure and properties of such elastomers were investigated. The crosslinking density of PUU elastomer was tested by the NMR method. It is found that when the content of HVA-2 is 1.5%, the mechanical properties of polyurethane elastomer achieve optimal performance. By testing thermal performance of PUU, compared with linear PUU, the thermal stability of the elastomers has a marked improvement. With the addition of HVA-2, the loss factor tanδ decreases. FT-IR spectral studies of PUU elastomer at various temperatures were performed. From this study, heat-resistance polyurethane could be prepared, and the properties of PUU at high temperature could be improved obviously. 相似文献
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氨基硅油改性聚丁二烯聚氨酯脲的合成与性能 总被引:6,自引:0,他引:6
过量的甲苯二异氰酸酯(TDI0加入氨乙基氨丙基聚二甲基硅氧烷(AEAPS),端羟基聚丁二烯(HTPB)中制成预聚体,以3,3′-二氯-4,4′二苯基甲烷二胺(MOCA)为固化剂,合成了一系列不同含量的硅氧烷改性聚丁二烯聚氨酯脲,通过接触角,表面光电子能谱(ESCA)测试,应用应变,动态力学热分析,结果表明,氨基硅油在聚氨酯脲表面明显富集,聚丁二烯聚氨酯脲的力学性能改变不大。 相似文献
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The effect of the concentration of benzoyl peroxide in poly(methyl methacrylate) bone cement formulations on their setting characteristics, particularly peak temperature and setting time, were studied. An optimization of the concentration of benzoyl peroxide was made with respect to curing parameters and compared with the residual monomer content. The mechanical properties of the different formulations were also determined and the results indicated that a composition of 1.5% wt/wt and 0.82% wt/wt of benzoyl peroxide and N,N-dimethyl-p-toluidine concentrations, respectively, gave the highest yield strength. Studies on the preparation of bone cement formulations containing different amounts of barium sulphate were also performed to assess the effect on the polymerization process and mechanical properties of the cements. 相似文献
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针对我国油气传输管道在高温高压(150~200℃,34~36 MPa)服役条件下的磨损腐蚀问题,以无溶剂环氧树脂体系为基础,通过固化剂及填料筛选、配方正交设计及黏度影响因素研究,研制了适用于油管内壁综合性能良好的耐温耐磨涂层材料。涂层采用固化反应温度更高以及力学性能更好的0421型固化剂,选择碳化硅、碳纤维和聚四氟乙烯作为填料,研究不同粒径的填料所制备涂层的力学性能和黏度,发现当碳化硅粒径为18μm,碳纤维粒径为75μm时,涂层力学性能更佳且黏度更低,同时通过正交试验确定了碳化硅、碳纤维和聚四氟乙烯的最佳用量分别为占树脂总量的30%、10%、5%,并在涂料体系黏度影响因素研究中发现聚四氟乙烯对体系的黏度影响最大。以上述试验为基础,最终研制出的涂料及涂层各项性能达到技术指标要求。 相似文献
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Omid Nabinejad D. Sujan Muhammad Ekhlasur Rahman Willey Yun Hsien Liew Ian J. Davies 《Applied Composite Materials》2018,25(6):1323-1337
This paper presents an experimental study on the development of hybrid composites comprising of multi-walled carbon nanotubes (MWCNTs) and natural filler (oil palm shell (OPS) powder) within unsaturated polyester (UP) matrix. The results revealed that the dispersion of pristine MWCNTs in the polymer matrix was strongly enhanced through use of the solvent mixing method assisted by ultrasonication. Four different solvents were investigated, namely, ethanol, methanol, styrene and acetone. The best compatibility with minimum side effects on the curing of the polyester resin was exhibited by the styrene solvent and this produced the maximum tensile and flexural properties of the resulting nanocomposites. A relatively small amount of pristine MWCNTs well dispersed within the natural filler polyester composite was found to be capable of improving mechanical properties of hybrid composite. However, increasing the MWCNT amount resulted in increased void content within the matrix due to an associated rapid increase in viscosity of the mixture during processing. Due to this phenomenon, the maximum tensile and flexural strengths of the hybrid composites were achieved at MWCNT contents of 0.2 to 0.4 phr and then declined for higher MWCNT amounts. The flexural modulus also experienced its peak at 0.4 phr MWCNT content whereas the tensile modulus exhibited a general decrease with increasing MWCNT content. Thermal stability analysis using TGA under an oxidative atmosphere showed that adding MWCNTs shifted the endset degradation temperature of the hybrid composite to a higher temperature. 相似文献
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目前水性环氧涂料以亲水性的固化剂为主,它们与树脂之间的相溶性不好,直接影响了涂料的固化成膜和涂层性能.为此,制备了固化剂为水分散型的水性环氧涂料,研究了其固化机理,重点讨论了不同用量的水和成膜助剂对涂料性能的影响.结果表明:环氧-水分散型固化剂涂料中的加水量对体系的黏度影响不大,而环氧-亲水性固化剂涂料中的加水量对体系的黏度影响较大;成膜助剂2,2,4-三甲基戊二醇-1,3单异丁酸酯(TEXANOL)的加入可以显著降低乳液的最低成膜温度,并可取得较好的成膜效果.研制的水性环氧涂料具有较好的综合性能. 相似文献