Effects of additives on fusion parameters of rigid PVC formulations

The effects of varying amounts of tribasic lead sulfate (TBLS), dibasic lead stearate (DBLS), neutral lead stearate (NLS), calcium stearate (Ca.St.), stearic acid (St.Ac.), and paraffin wax (PW) on the fusion properties of a rigid PVC formulation were investigated. The materials showed varying effects on fusion. Thus, fusion time was lowered and fusion factor increased by TBLS, DBLS, and Ca.St., while the reverse was true with NLS, St.Ac., and PW. The behavior of the materials is discussed in terms of their effects on the transformation of PVC grains. J. VINYL ADDIT. TECHNOL., 2008. © 2008 Society of Plastics Engineers.     

Calcium stearate–stearic acid as lubricants for rigid poly(vinyl chloride) (PVC). Capillary rheometer measurements and extrusion properties

Capillary rheometer measurements show that stearic acid can be characterized as a normal lubricant. If the content of stearic acid is increased in rigid PVC formulations, the melt viscosity will decrease. This leads to a corresponding increase of shear rate and volumetric flow rate. The influence of calcium stearate is opposite to the normal characteristic of a lubricant. Increasing amounts of calcium stearate lead to an increased melt viscosity and a decreased shear rate and volumetric flow rate. In the extrusion of rigid PVC, the apparent “lubricating” effect of calcium stearate is probably due to the increased friction with resulting heat evolution and higher mass temperature, leading to a decreased viscosity of the plastic melt. This is in agreement with the results of the extrusion experiments. Both mass temperature and power consumption decrease when stearic acid is added and increase when calcium stearate is added to the formulation.     

发泡剂AC的热分解活化机理及影响因素*

采用动力学和热力学相结合的方法,用自行设计的发泡剂发气量测量装置研究了重金属盐、金属氧化物、有机酸及其盐等对发泡剂ＡＣ热分解特性的影响;用ＤＳＣ差示扫描量热仪测定了各体系的动态分解温度和热效应。结果表明,三盐基硫酸铅、二盐基亚磷酸铅、硬脂酸铅和柠檬酸对发泡剂ＡＣ都有较强的活化作用,属于加速型发泡助剂;氧化锌是发泡剂ＡＣ较理想的活化引发剂,当其用量为０１份时,活化作用较好;而硬脂酸、硬脂酸钡和柠檬酸钠的活化作用较小,属于延缓型发泡助剂     

Development of a PVC Waterproofing Sheet

Stabilizer and plasticizer systems were studied for a PVC waterproofing sheet formulation to be processed by calendering. Combinations of stabilizer-lubricant systems that contained (Ba, Cd, Zn), dibasic lead phosphite, epoxidized soybean oil, barium stearate, calcium stearate, and stearic acid were evaluated. Oven aging tests showed that the system that contained 2 phr (Ba, Cd, Zn) stabilizer, 0.5 phr barium stearate, 5 phr epoxidized soybean oil, and 0.25 phr stearic acid was satisfactory. Combinations of diisodecylphthalate (DIIP), tricresyl phosphate (TCP), polybutylene adipate (PBA), and NBR were evaluated as the plasticizer system. Tensile properties in the machine and the transverse directions, cold flex temperature, loss of volatile matter content, and aging properties were studied as functions of the DIIP and PBA contents. A plasticizer system of 35 phr DIIP and 18 phr PBA was found to be satisfactory. The final formulation was processed at industrial scale and the product was characterized for its tensile properties, cold flex temperature, tear resistance, weldability, permeability to water, shrinkage, and its resistance to heat, light, acid, and water.     

The reinitiation mechanism of HCl catalysis in PVC degradation

Summary The effect of HCl on the thermal degradation of PVC has been studied. Changes in UV and visible spectra and kinetics of HCl loss indicate that HCl is able to reinitiate the allyl-activated zip elimination by proton exchange with polyenes. Also polyene-consuming secondary reactions are accelerated by HCl.     

Development of a continuous process for enol esters of fatty acids

A continuous process for the production of iso-propenyl stearate from stearic acid and propyne was developed. The reaction proceeds at elevated pres-sures and temperatures (∼550 psig and 400 F, respec-tively) in about l0 min. A slower, second reaction produces stearic anhydride from the isopropenyl stearate. A recovery section was devised, wherein the liquid product stream is chilled, recovered as flakes, and extracted with a solvent, e.g. Skelly B. Reaction studies were scaled-up from 10 to 40 lb feed/hr using triple pressed stearic acid and MAPP® gas (AIRCO, Inc., Montvale, NJ), a commercially available gas con-taining a nominal 1/3 propyne, 1/3 propadiene, and 1/3 stabilizing, saturated hydrocarbons. The acid and propyne are reacted in the presence of zinc stearate in a continuous stirred tank reactor (CSTR). The reac-tion is “finished” in a short tubular reactor. Data are presented on the effect of pressure, temperature, catalyst level, dwell in the reactors, and solvent ratio during extraction. The product is about 92% iso-propenyl ester, contaminated with unconverted stearic acid and by-product stearic anhydride.     

Comparison of mesoporous aluminas synthesized using stearic acid and its salts

Mesoporous aluminas, X-MAs (X=Na, Mg, and Ni) were prepared using stearic acid and its salts as templates. Sodium stearate, which is more soluble than stearic acid, was an effective template for preparing Na-MA. The characteristics of Mg-MA prepared using cost-effective template (magnesium stearate) were similar to those for an MA prepared using stearic acid. Mg ions were easily exchanged with Ni ion by treatment with an acid or base. Thus, nickel incorporated alumina (Ni-MA) could be directly prepared using nickel stearate, which was acting as a chemical template and a metal source. The MA and X-MAs had a similar pore size (3.6 nm), a narrow pore size distribution (D_FWHM∼1 nm), and a γ-alumina phase. In addition, bimetallic Ni-MAn catalysts were prepared and applied to the partial oxidation methane as a potential application.     

对甲苯磺酸催化合成硬脂酸甲酯

以对甲苯磺酸催化硬脂酸和甲醇的酯化反应,合成了硬脂酸甲酯,研究结果表明,对甲苯磺酸对酯化反应具有较高的催化活性。考察了反应时间、酸醇摩尔比、催化剂用量对酯化反应的影响。当硬脂酸与甲醇的摩尔比为1∶3.5,对甲苯磺酸用量为硬脂酸质量的1.2%,于回流温度反应4 h,硬脂酸的转化率大于98.5%,产品酸值小于3.0 mg KOH/g。     

A DSC study of curative interactions. I. The interaction of ZnO,sulfur, and stearic acid

The interaction between combinations of sulfur, stearic acid, and ZnO were studied by differential scanning calorimetry in the absence of rubber. The only reaction observed was between ZnO and stearic acid. A small amount of zinc stearate formed as soon as the stearic acid melted, but the solid product blocked further reaction, which was only completed at 154°C. Water played a major role in the reaction, and in the presence of water, the reaction went to completion at lower temperatures. Sulfur, too, affected the temperature of the ZnO/stearic acid reaction. The preparation of zinc stearate by a number of routes was investigated.     

A differential scanning calorimetric study of the interaction of zinc benzothiazole-2-thiolate,sulfur, stearic acid,and zinc stearate in the absence and presence of polyisoprene

The interactions between mixtures of zinc benzothiazole-2-thiolate (ZMBT), sulfur, stearic acid, and zinc stearate were studied by DSC in the absence and presence of polyisoprene (IR). It was established that ZMBT reacts with stearic acid to form zinc stearate and 2-mercaptobenzothiazole (MBT). In the presence of stearate compounds, MBT is readily available from the start of vulcanization, whereas it becomes only slowly available in the absence of these compounds. The effectiveness of the vulcanization process increases for the systems IR/ZMBT/sulfur < IR/ZMBT/sulfur/stearic acid < IR/ZMBT/sulfur/zinc stearate. In view of the above results, interaction mechanisms are proposed for the different systems. © 1993 John Wiley & Sons, Inc.     

可逆热透明成像材料记录层的制备及形态与性能的研究

以纤维素为基体树脂,硬脂酸、聚乙二醇硬脂酸酯等为添加物,制备了1种可逆热透明成像材料的热敏记录层。利用差示扫描量热仪、偏光显微镜等研究了记录层材料热变化中的形态与性能。研究表明,该记录层具有良好的热光性质,硬脂酸和聚乙二醇硬脂酸酯的协同作用使得记录层的光学和热学性质有了进一步的提高。     

Polymer degradation by elimination of small molecules

An outline of a method of deriving the kinetic equations for polymer degradation by the elimination of low molecular weight compounds is presented. The method is based on the stochastic approach. The main ideas are that the degradation occurs via the zip mechanism and that the initiating step, i.e. the formation of an olefinic site in the polymer chain, takes place at random. Three mechanisms have been investigated in this study: (i) ordinary zip mechanism; (ii) autocatalytic mechanism with immediate zip growth and catalyzed initiation; (iii) autocatalytic mechanism with gradual zip growth. The kinetic equations derived have been used in kinetic studies of the dehydrochlorination of PVC in inert, HCl, and oxidative atmospheres, and of the degradation of polyvinyl esters, polyvinyl bromide and polyvinylidene chloride. Kinetic parameters for the degradation of individual polymers have been obtained.     

PVC五金件专用料的热稳定性研究

研究了多种稳定剂以及它们之间的相互协同作用对PVC五金件专用料的热稳定性的影响 ,结果表明 :选用三盐基硫酸铅作为主稳定剂 ,二盐基亚磷酸铅、硬脂酸钡和硬脂酸作为助稳定剂 ,在适当的配比下 ,再配合使用环氧大豆油和亚磷酸三苯酯将可使PVC的动态热稳定时间提高到 36min     

Characterization of maleic anhydride-grafted ethylene–propylene–diene terpolymer (MAH-g-EPDM) based thermoplastic elastomers by formation of zinc ionomer

Thermoplastic elastomers (TPEs) composed of maleic anhydride-grafted ethylene–propylene–diene terpolymer (MAH-g-EPDM) and ZnO were characterized using IR, TGA, solvent extraction, crosslink density, and physical properties. The degree of the ionomer formation increased with increasing the zinc oxide content, and it was also enhanced by adding stearic acid or zinc stearate. The crosslink densities were measured using a solvent swelling method using toluene, xylene, and 1,2-dichlorobenzene. The crosslink density increased when increasing the zinc oxide content. By adding stearic acid or zinc stearate, heteroionic bonds were formed and the crosslink density notably enhanced. The physical properties were dependent on the crosslink densities.     

Effects of stearates on the thermal stability of chlorinated natural rubber from latex

The effects of stearates on the dehydrochlorination (DHC) reaction of chlorinated natural rubber (CNR) from latex were studied by the measurement of the HCl evolving rate during the early stage of the thermal degradation of CNR and by the determination of the amounts of cyclic conjugated dienes formed on the CNR molecular chains. During the early stage of the thermal degradation of CNR at 150°C, HCl was eliminated from the CNR molecular chains, and the cyclic conjugated dienes were formed on the CNR molecular chains. Under the effects of barium stearate, lead stearate, cadmium stearate, and calcium stearate, the HCl evolving rates of CNR were reduced, whereas the amounts of cyclic conjugated dienes that formed on the CNR molecular chains were increased. When zinc stearate was added, because of the formation of ZnCl₂, which was an active catalyst of the DHC reaction of CNR, both the HCl evolving rate from CNR and the formation of cyclic conjugated dienes were increased. The results indicate that the addition of stearates can reduce the thermal stability of CNR. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1981–1985, 2006     

The preparation of cotton fabric with super-hydrophobicity and antibacterial properties by the modification of the stearic acid

In this article, the superhydrophobic and antibacterial surface on the cotton fabric were fabricated with the UV curable waterborne coatings, the silver nanoparticles, and the stearic acid. The cotton fabric coated with silver stearate was obtained by immersing in a mixture of sodium hydroxide and then modified by stearic acid. Results showed that the water contact angle on the surface of the fabric was 157.6°. The micromorphology and chemical ingredients of the surface of the coating were studied by scanning electron microscope, Fourier transforms infrared spectroscopy, and X photoelectric spectrometer. Results showed that the immersion resulted in a double decomposition reaction and with the modification of the stearic acid, the silver stearate was formed on the surface, which provided a rough surface required for super-hydrophobicity. And the acid and alkali resistance test, water-resistance test, and antibacterial activity test indicated that the coating had good acid and alkaline resistance, water-resistance, and antibacterial properties.     

Analysis of whitening phenomenon of EPDM article by humid aging

An ethylene–propylene–diene terpolymer (EPDM) article used for a car component was aged in 80°C humid air (60% relative humidity) for 30 days and in 80°C tap water for 7 days. The aged sample surfaces were changed to white. The aged sample surfaces were analyzed using GC/MS, image analyzer, SEM, EDX, and ATR‐FTIR. Calcium stearate was found on the aged sample surface. To confirm the whitening phenomenon, three sulfur‐cured EPDM composites with different reinforcing systems (talc/carbon black, calcium carbonate/carbon black, and clay/carbon black) and one resole‐cured EPDM composite were prepared and aged in 90°C tap water for 7 days. The sulfur‐cured EPDM composites contained stearic acid, whereas the resole‐cured EPDM composite did not contain stearic acid. Whitening occurred in the sulfur‐cured EPDM samples irrespective of the filler systems but the aged resole‐cured EPDM composite surface was not changed. The whitening was due to the formation of calcium stearate as a result of reaction between calcium cation and stearic acid. The calcium cation came from humid air and tap water, while the stearic acid came from the sulfur‐cured EPDM samples. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

硬脂酸钕热稳定剂的改进复分解法合成研究

采用改进复合分解法合成硬脂酸钕,通过均匀设计实验,分析了反应温度、硝酸钕浓度、硬脂酸浓度、氢氧化钠浓度、氢氧化钠滴加时间、保温时间6个因素对合成反应的影响,确定较合适的合成工艺条件.采用电导率法测定硬脂酸钕对聚氯乙烯(PVC)的热稳定性能,结果表明硬脂酸钕热稳定性效果优异.     

UV光固化热敏记录层机理的研究

以光固化丙烯酸酯树脂作为基体，硬脂酸、聚乙二醇硬脂酸酯等为添加物，制备了一种可逆热透明成像材料的UV光固化热敏记录层。利用DSC仪、偏光显微镜以及X射线衍射仪研究了添加的硬脂酸和聚乙二醇硬脂酸酯对UV光固化热敏层的作用机理。研究结果表明，硬脂酸和聚乙二醇硬脂酸酯结晶态与无定形态之间的转变是UV光固化热敏层发生白色浑浊态与透明态转变的直接原因，且两者的共同作用扩大了UV光固化热敏层的显透温度范围，另外，利用热分析仪对热塑性热敏层和光固化热敏层的耐热性作了比较。结果表明，UV光固化热敏层在升温过程中的热损失较热塑性的热敏层有明显降低。     

直接法合成硬脂酸锌的正交试验设计及最佳工艺条件的确定

研究了硬脂酸和氧化锌在催化剂作用下直接合成硬脂酸锌的方法 ,并通过正交试验和验证实验确定了合成的最佳工艺条件 :反应时间 90min ,反应温度 135℃ ,过氧化物作催化剂 ,其用量为硬脂酸量的 3%。以此工艺生产的硬脂酸锌质量与文献值相符 ,且流程缩短 ,工艺简单 ,成本低 ,无废水