聚乙烯醇/改性纳米蒙脱土复合材料的制备与性能

纳米蒙脱土(MMT)用十六烷基三甲基溴化铵进行改性制得有机改性的MMT(OMMT),用其作为聚乙烯醇(PVAL)的改性材料,采用溶液共混、流涎成膜制得PLA/OMMT复合材料,考察了OMMT的用量对PVAL复合材料性能的影响。用傅立叶变换红外光谱(FTIR)仪、差示扫描量热仪、扫描电子显微镜、X射线衍射仪、万能力学试验机等对复合材料性能及结构进行表征和分析。结果表明,FTIR显示十六烷基三甲基溴化铵成功进入MMT结构中,OMMT成功制得;随着OMMT添加量的增加,复合材料热稳定性提高,断裂伸长率降低,拉伸强度呈现先增加后降低趋势,当其含量为9%时达到最大;SEM显示OMMT含量9%时,OMMT与PVAL相容性最好,表面光滑,含量再增加,出现团聚现象,力学性能受到影响。     

PVA纤维表面改性对水泥基复合材料弯曲性能的影响

采用有机硅柔软剂对国产聚乙烯醇(PVA)纤维进行表面改性,并制备了纤维增强水泥基复合材料(PVA-ECC)。采用扫描电子显微镜研究了有机硅柔软剂改性对PVA纤维表面结构的影响,用三点弯曲试验研究了有机硅柔软剂改性的PVA纤维对PVA-ECC复合材料弯曲性能的影响。研究结果表明:随着有机硅柔软剂含量的增加,PVA-ECC的极限弯曲强度和极限跨中挠度均先增加再减小,当有机硅柔软剂质量分数为7%时,极限弯曲强度和极限跨中挠度达到最大值,分别为5.627 MPa和2.123 mm;用ASTM C1609标准分析PVA-ECC三点弯曲韧性,当有机硅柔软剂质量分数为7%时,弯曲韧性达到最大值。     

乳酸酯化接枝改性聚乙烯醇的研究

乳酸与聚乙烯醇酯化接枝反应对聚乙烯醇进行改性,以改善聚乙烯醇的室温水溶性、热塑加工性及生物降解性能。采用红外光谱和X射线衍射对产物的结构进行了表征,并通过正交试验考察了酯化反应时间、温度、摩尔比和聚乙烯醇的相对分子质量对胶黏剂性能的影响。确定了合成工艺的最佳条件为:乳酸和聚乙烯醇的摩尔比为1∶2,反应温度125～130℃;反应时间3h,催化为氯化亚锡。     

偶合接枝聚乙二醇单甲醚实现聚砜膜材亲水性改性

采用自制的氯甲基化试剂1,4-二氯甲氧基丁烷实施聚砜(PSF)的氯甲基化,再以Na2CO3为缚酸剂,使氯甲基化聚砜(CMPSF)的氯甲基与聚乙二醇单甲醚(PEGME)的端羟基之间发生亲核取代反应,将聚乙二醇(PEG)偶合接枝在聚砜侧链上,制得接枝共聚物PSF-g-PEG,实现了聚砜膜材的亲水性改性.表征了其化学结构,考...     

高密度聚乙烯／木粉复合材料熔融性能及表面张力的研究

探讨了木粉及马来酸酐接枝聚乙烯(MAPE)对高密度聚乙烯(HDPE)/木粉复合材料熔融性能及表面张力的影响。结果表明:复合材料的起始熔融温度均略高于纯HDPE的,熔融峰的面积及形状介于纯木粉与纯HDPE之间,复合材料的表面张力及其极性组分均随木粉的质量分数逐渐增加。使用MAPE将提高复合材料熔融峰的面积,复合材料更难被熔化。质量分数为5%、10%的MAPE的复合材料的表面张力较低;而质量分数为15%及20%的MAPE的复合材料的表面张力与无MAPE的复合材料的基本相等。     

软质聚氯乙烯复合材料的制备与性能

以聚氯乙烯(PVC)为基体树脂,研究不同增塑剂对软质聚氯乙烯复合材料邵氏硬度、拉伸强度和断裂伸长率的影响。结果表明:添加邻苯二甲酸二辛酯(DOP)制备软质PVC复合材料邵氏硬度大,但是添加乙酰柠檬酸三丁酯(ATBC)作为增塑剂制备软质PVC复合材料中的拉伸强度和断裂伸长率较大。     

Effect of Interfacial Interaction on Morphology and Properties of Polyethylene/Boron Nitride Thermally Conductive Composites

In this study, polyethylene-g-maleic anhydride was utilized to enhance interfacial interaction between boron nitride and polyethylene. Moreover, KH550 was used as a surface treatment agent to improve interfacial interaction between boron nitride and polyethylene. It was found that surface functionalization of boron nitride particles and the addition of polyethylene-g-maleic anhydride can promote dispersion of boron nitride particles with reduced aggregation, resulting in the improvement of both tensile and impact strength of polyethylene/boron nitride composites. Compared to surface functionalization of boron nitride particles, the addition of polyethylene-g-maleic anhydride was much effective to enhance thermal conductivity of polyethylene/boron nitride composites and drop effectively rheological percolation threshold and gel point of polyethylene/boron nitride composites.     

聚乙烯醇缩丁醛作为界面改性剂制备聚已二酸-对苯二甲酸丁二酯/竹粉复合材料

将聚乙烯醇缩丁醛（PVB）作为非反应型界面改性剂用于聚已二酸-对苯二甲酸丁二酯（PBAT）/竹粉木塑复合材料的制备,考察了其界面改性效果及对材料力学性能的影响。PVB分子中的羟基与缩醛基可以分别与竹粉表面的极性基团以及树脂基体相互作用,从而提高复合材料的界面相容性。结果表明,PVB直接添加或溶液添加对复合材料的力学性能影响不大;PVB使PBAT与竹粉的界面结合明显改善。在竹粉含量为30 %（质量分数,下同）下,PVB含量为竹粉含量的1 %时,复合材料的拉伸强度从5.16 MPa提高到6.02 MPa。     

聚乙烯醇脱氢酶的分离纯化及其酶学性质

采用(NH4)2SO4分级沉淀及Q-Sepharose HP柱层析两步纯化,首次从可高效降解聚乙烯醇(PVA)的混合菌系发酵产物中分离纯化获得了纯蛋白聚乙烯醇脱氢酶(PVADH),并对其酶学性质进行了研究. 结果表明,PVADH分子量为134.3 kDa,最适作用温度为35℃,最适作用pH值为7.5;PVADH以仲醇为底物时酶活性普遍高于以其他醇类为底物时,PVADH与PVA反应产物中检测到羰基化合物,证实PVADH对PVA有降解作用.     

聚乙二醇二甲醚的物化性质

收集整理了聚乙二醇二甲醚的物化数据,并给出若干图表,可供天然气净化厂、煤气净化厂、石油化工厂、炼油厂、合成氨厂、焦炉气厂和发电厂烟道气等有关气体净化的科研、设计和生产管理人员使用。     

聚乙二醇接枝聚羧酸合成水泥减水剂的研究

采用先酯化后聚合方法合成了聚乙二醇接枝聚羧酸钠水泥减水剂,考察了单体配比、滴加时间、磺酸单体种类及用量和反应温度对产品性能的影响.实验结果表明,在滴加时间和保温反应时间都为3.5 h时,合成的减水剂性能良好;当减水剂用量为水泥用量的0.3%时,净浆流动度高达310 mm.由水泥的净浆流动度实验表明,合成的水泥减水剂对水泥具有良好的减水性能.     

Improving Interfacial and Compressive Properties of Aramid by Synchronously Grafting and Crosslinking

Improving compressive strength of aramid and its adhesion to resin is of great significance for its application in reinforcing materials. In this study, a novel method for improving interfacial and compressive properties of aramid fiber is presented. α,α′‐Dichloro‐p‐xylene (DCX) is utilized as an external crosslinker to modify aramid fiber containing benzimidazole units during the post swelling process. Chloromethyl groups from DCX can react with benzimidazole moieties of the aramid fiber. The reaction can be regarded as crosslinking inside the fiber and grafting on the surface. By controlling the swelling effect of the solvent during modification, bulk crosslinking degree and surface grafting density can be adjusted. Therefore, intermolecular interaction and surface polarity of the aramid fiber can be improved simultaneously. After modification, the compressive strength of the fiber can be enhanced by nearly 100% and interfacial shear strength increases by 37%, while excellent mechanical properties are maintained. Therefore, comprehensive performance of aramid fiber can be improved significantly by synchronously crosslinking and grafting.     

Interfacial Properties of Polyethylene Glycol/Vinyltriethoxysilane (PEG/VTES) Copolymers and their Application to Stain Resistance

In this study, polyethylene glycol (PEG) and vinyltriethoxysilane (VTES) were used in different proportions to produce a series of PEG-VTES copolymers. The copolymer molecular structures were confirmed by FTIR spectroscopy. In addition, their surface activities were evaluated by evaluating the surface tension, contact angle, and foaming properties. The results showed that these surfactants exhibited excellent surface activities and wetting power, as well as low foaming. Consequently, the application of a series of PEG/VTES copolymers can make cotton fabrics stain resistant.     

Physicochemical Studies on the Interfacial and Micellization Behavior of CTAB in Aqueous Polyethylene Glycol Media

Interfacial and micellization behavior of cetyltrimethylammonium bromide (CTAB) have been studied in aqueous polyethylene glycol (PEG) mixed solvent systems of varying concentrations and molar mass. Interfacial behavior of CTAB was investigated by the equilibrium surface tension method. Conductance studies of surfactant solutions under different condition helped in determining the critical micelle concentration (CMC) and degree of dissociation of CTAB micelles. In addition, the limiting molar conductivity of surfactant and micellar species were evaluated from the differential plots. The CMC of CTAB was found to increase with increasing PEG concentration as well as its molar mass, although, the process of interfacial adsorption and micellization was found to be spontaneous, as evidenced by negative free energy change. The viscosity of CTAB micelles in aqueous-PEG mixtures was found to increase with the increase in PEG concentration and molar mass. Dynamic light scattering measurements revealed a size enhancement effect contributed by the PEG oligomers. An increase in the CMC of CTAB and the subsequent presence of a higher number of ionic species in their dissociated form was further established by an overall increase in the zeta potential value in the presence of PEG oligomers. It is proposed that the PEG could wrap around the micelles through their conformational changes. Results also suggest that PEG oligomers could give solvophobic effect which enhances the CMC of CTAB compared to that in pure water.     

改性聚乙二醇多磺酸基水处理剂的制备及性能

以过硫酸铵为引发剂,以马来酸酐改性聚乙二醇得到的聚乙二醇酯(PEGMA)、乙烯基磺酸钠(SVS)、丙烯酸(AA)为单体,通过水相自由基共聚反应制备目标共聚物PEGMA-SVS-AA。考察了聚合工艺对其阻碳酸钙垢性能的影响,利用红外光谱对共聚物结构进行表征,得到最佳聚合反应条件为:n(PEGMA)∶n(SVS)∶n(AA)为1∶3∶5,过硫酸铵用量为单体总质量的6%,反应时间2.5 h,控制反应温度为80℃。在该条件下制备的聚合物PEGMA-SVS-AA在模拟工业生产循环冷却水条件下,其阻碳酸钙垢率达到89%。使用XRD和SEM对碳酸钙垢进行了表征,该水处理剂不仅改变了碳酸钙的形貌而且改变了碳酸钙的晶型。     

聚乙二醇改性菜籽油的碱催化合成及性能

在固体碱催化下,由菜籽油改性制得的菜籽油脂肪酸甲酯与聚乙二醇400(PEG400)进行酯交换反应,合成了绿色可降解的多功能非离子表面活性剂聚乙二醇脂肪酸酯。对酯交换反应的主要影响因素和产物性能进行了考察。结果表明,在m(菜籽油脂肪酸甲酯)∶m(PEG400)=2.0∶1.0,催化剂w(CaO/ZrO2)=0.8%(相对于反应物总质量),温度130℃,反应时间7.5h的条件下,聚乙二醇脂肪酸酯产率达91.56%;产物浊点53℃、表面张力35mN/m、乳化性361s、润湿力59s,说明具有很好的表面活性。     

Graphene Oxide as a Prospective Graft in Polyethylene Glycol for Enhancing the Toughness of Epoxy Nanocomposites

Polyethylene glycol (PEG) was successfully grafted onto the surface of graphene oxide (GO) by the “grafting to” technique. PEG, GO as well as the PEG grafted GO (GO-g-PEG) was successfully incorporated into an epoxy matrix and subsequently cured using diethylenetoluenediamine (DETDA) to make epoxy nanocomposites. Mechanical, thermal, and rheological properties of the epoxy nanocomposites were studied to check the effectiveness of these fillers in the epoxy matrix. An improvement of 255% and 334% at a very low filler loading of about 0.1 wt% was observed in the fracture toughness of GO and GO-g-PEG loaded systems versus the neat epoxy. Toughening mechanisms are also explained by analyzing SEM images of the fractured surface. Modeling of rheological properties was carried out by following time-independent Newtonian model. The homogeneity of the epoxy filler systems are explained with the help of Cole–Cole plots. The thermal stability of the filler loaded epoxy composites was examined in detail by TGA. Improvements in mechanical properties reveal the potential benefit of the grafting process in epoxy toughening. POLYM. ENG. SCI., 60:773–781, 2020. © 2020 Society of Plastics Engineers     

加强聚乙烯醇应用开发实现行业持续发展

文章通过阐述聚乙烯醇应用研究的必要性，介绍国内外聚乙烯醇应用研究最新动态，指出了我国聚乙烯醇工业的发展方向——即通过加强聚乙烯醇应用研究，拓宽产品应用领域；研发科技含量高、附加价值高的下游产品，延长产品链，提升企业核心竞争能力，促进行业可持续发展。     

利用响应面分析法优化聚乙烯醇水凝胶面膜配方

制备聚乙烯醇水凝胶面膜,运用单因素实验确定影响聚乙烯醇水凝胶面膜粘度的主要因素,应用响应面分析法对聚乙烯醇水凝胶面膜的配方进行优化,最后通过兔耳-黑头粉刺模型验证水凝胶面膜祛黑头的性能。