新型润滑剂WB16对SBR和EPDM流变性能影响的研究

研究了新型润滑剂WB16对SBR和EPDM混炼胶流变性能的影响。结果表明:WB16均能降低两种混炼胶的表观粘度,改善其流动性,并使混炼胶粘度对温度的敏感性增加,挤出物胀大比随WB16的增加而降低,表明该助剂可降低混炼胶的弹性,提高其塑性行为。     

新型加工助剂WB16对BR和CR流变性能影响的研究

采用XLY-2型毛细管流变仪研究了新型加工助剂WB16对BR和CR两种合成橡胶流变性能的影响。结果表明:WB16均能降低两种混炼胶的表观粘度,改善流动性,并可提高混炼胶粘度对温度的敏感性,但WB16的添入未能改变两种合成胶产生不稳定流动的临界剪切应力值。     

用WB16改善合成橡胶的加工性能

本工作通过胶料的流动性、可塑性、硫化特性、力学性能和老化性能的测试,试验了加工助剂WB16对BR、SBR、CR、EPDM四种合成橡胶加工性能和力学性能的影响。结果表明,加入少量WB16即可明显地降低胶料的表观粘度,提高胶料流动性,而对胶料的力学性能和热老化性能无明显的不利影响。是一种值得推广的新型橡胶加工助剂。     

硫化助剂、加工助剂和软化剂对HNBR加工性及可塑性的影响

测定并对比了与不同用量硫化助剂(Sartomer TRIM和Sartomer ZDA)、加工助剂(Struktol WB 222和Struktol NS 60)及软化剂(TOTM)混合的炭黑填充氢化丁腈橡胶(HNBR)的流变性能。含有这些化合物,HNBR混炼胶的加工性和可塑性均有不同程度的提高。Struktol WB 222的改善幅度最大,而Sartomer ZDA的最低。HNBR混炼胶的硫化特性受添加的丙烯酸类化合物(如Sartomer TRIM和Sartomer ZDA)的影响,致使硫化速率及硫化状态增强,而添加Struktol WB 222、Struktol NS 60、TOTM则表现出相反的变化趋势。     

LLDPE-g-AA的流变行为及力学性能

利用毛细管流变仪研究了线性低密度聚乙烯接枝丙烯酸 (LLDPE - g -AA)的流变行为。结果表明 ,在高的剪切应力下LLDPE -g -AA的表观粘度比纯LLDPE的小 ,并改进了树脂的流动性和加工性。LLDPE - g -AA的表观粘度随接枝丙烯酸含量的增加而降低 ,说明接枝到LLDPE分子链上的丙烯酸起到了内润滑剂的作用。利用Instron 112 1拉力机测试了LLDPE - g -AA的力学性能 ,结果表明其拉伸强度、杨氏模量和断裂伸长率与纯LLDPE相比没有明显的变化     

线性低密度聚乙烯接枝丙烯酸的流变行为及力学性能

利用毛细管流变仪研究了线性低密度聚乙烯接枝丙烯酸（LLDPE-g-AA)的流变行为,结果表明,在高的剪切应力下LLDPE-g-AA的表观粘度比纯LLDPE的小,LLDPE-g-AA的流动性提高了,其加工性能变好,LL-DPE-g-AA的表观粘度随接枝丙烯酸含量的增加而降低,这说明接枝到LLDPE分子链上的丙烯酸起到了内润滑剂的作用。利用Instron1121拉力机测试了LLDPE-g-AA的力学性能,结果表明,其拉伸强度、杨氏模量和断裂伸长率与纯LLDPE的相应性能没有明显的变化。     

稀土顺丁橡胶与镍系顺丁橡胶流变性能的研究

本工作采用Instron 3211毛细管流变仪,对典型稀土顺丁橡胶(LnBR)及其充油胶(LnOBR)样品,以及镍系顺丁橡胶(NiBR)工业产品的流变性能进行了考察和比较。结果表明,LnBR、LnOBR、NiBR生胶在70℃时都是假塑性流体,其流变指数n分别小于0.4、0.6、0.5,且有不同的表观粘度。混炼胶也都是假塑性流体,其非牛顿性的大小,随挤出温度与切变速率而变化。实验条件下,LnBR、LnOBR、NiBR 混炼胶的 n值分别小于 0.6、0.4、0.6。在 120—140℃低切变速率下操作,胶料的弹性记忆效应最小。LnBR熔体破裂比NiBR严重。LnBR、LnOBR、NiBR在 120—140℃下得到光滑挤出物的临界切变速率分别为 35、40、100秒~(-1) 。     

润滑剂的种类及PE蜡的用量对氟橡胶性能的影响

研究了6种不同种类的润滑剂以及不同量的PE（聚乙烯）蜡对氟橡胶FKM混炼胶加工硫化性能、硫化胶机械力学性能的影响。结果表明：不同种类的润滑剂对氟橡胶混炼胶的影响效果不同，PE蜡在适当用量的条件下，对氟橡胶的加工性能和拉伸性能均有较好的效果，经300℃热空气老化24h后，强伸性能的保持率也比较好。     

疏水改性黄原胶XG-C16溶液性能及微观结构探究

以1-溴代十六烷为醚化试剂,对黄原胶(XG)进行改性,制备了疏水改性黄原胶(XG-C16),研究了XG-C16溶液的溶液性能和微观形貌。结果表明,XG-C16溶液的表观粘度显著增加,缔合后的XG-C16溶液在140℃下表观粘度是相同浓度下XG溶液表观粘度的3.4倍,临界缔合浓度(CAC)为0.16%;相较于XG,XG-C16溶液具有更好的空间网状结构,表现出更加优良的耐温、耐剪切性能,在5.0%的NaCl加量下,缔合后的XG-C16溶液能保持较好的空间网状结构,抗盐曲线出现轻微的盐增稠效应。     

疏水改性黄原胶XG-C16溶液性能及微观结构探究

以1-溴代十六烷为醚化试剂,对黄原胶(XG)进行改性,制备了疏水改性黄原胶(XG-C16),研究了XG-C16溶液的溶液性能和微观形貌。结果表明,XG-C16溶液的表观粘度显著增加,缔合后的XG-C16溶液在140℃下表观粘度是相同浓度下XG溶液表观粘度的3.4倍,临界缔合浓度(CAC)为0.16%;相较于XG,XG-C16溶液具有更好的空间网状结构,表现出更加优良的耐温、耐剪切性能,在5.0%的NaCl加量下,缔合后的XG-C16溶液能保持较好的空间网状结构,抗盐曲线出现轻微的盐增稠效应。     

A STUDY OF CARBON BLACK DISTRIBUTION AND PROPERTIES IN BR/NBR BLENDS: ROLES OF COMMERCIAL HOMOGENIZER AND SLIPPING AGENT

Effects of commercial processing aids, Struktol NS60 (hydrocarbon resin) homogenizer and Struktol WB16 (a mixture of metal salt and a fatty acid amide) slipping agent on the distribution of carbon black and physical properties in BR/NBR blends have been investigated. It was found that Struktol 60NS and Struktol WB16 in blend systems migrate preferentially to BR phase due to the strong interaction between Struktol and BR phase, leading to a decrease in viscosity of BR phase and thus an increase in carbon black residing in BR phase. Mechanical properties of unfilled compounds are strongly affected by blend ratio and loading of processing aids. However, in the case of filled compounds, the influence of carbon black distribution in each phase of the blends override those blend ratio and additive loading effects.     

Characterization and biodegradability of agricultural residue-filled polyester ecocomposites

The biodegradability and mechanical and thermal properties of composites of maleic anhydride-grafted polybutylene succinate (PBSU-g-MA) and agricultural residue (wheat bran, WB) were evaluated. Composites of PBSU-g-MA and WB (PBSU-g-MA/WB) exhibited superior mechanical properties compared to PBSU/WB due to better compatibility. The dispersion of WB in the PBSU-g-MA matrix was highly homogeneous due to ester formation between the anhydride groups of PBSU-g-MA and the hydroxyl groups of WB, which resulted in the formation of branched, crosslinked macromolecules. PBSU-g-MA/WB composites were more easily processed due to their lower melt viscosity. They also showed better water resistance, although both composites were biodegradable, especially at higher levels of WB substitution. Both composites were more biodegradable than pure PBSU, implying a strong connection between WB content and biodegradability.     

3种流动分散剂在丁基橡胶胶料中的应用研究

对比研究流动分散剂RL16,WB16和AC617对丁基橡胶胶料性能的影响.结果表明:3种流动分散剂均能提高胶料的流动性和填料的分散性,RL16和WB16的改善效果优于AC617;加入RL16和WB16的胶料焦烧时间和t90有所延长,硫化胶的100％和300％定伸应力减小,拉断伸长率增大,而AC617对硫化胶的物理性能影响较小;加入RL16和WB16的硫化胶耐热空气老化性能和耐压缩永久变形性能有所下降,影响程度略高于AC617.     

Influence of some additives on state‐of‐mix,rheological, tensile,and dynamic mechanical properties in SBR compounds

The influence of some additives (Flexon processing oil, Struktol WB 16 slipping agent, and Struktol NS 60 homogenizing resin) on state‐of‐mix, rheological, tensile, and dynamic mechanical properties were investigated. It was found that extrudate swell of the rubber compounds with either processing oil or NS 60 is governed mainly by the state‐of‐mix, but by wall slip in the case of compounds with WB 16. As for the dynamic mechanical properties, the plasticizing effect is the major factor controlling the properties in the case of processing oil, while the degree of crosslink and dilution effect are the main factors in the case of NS 60. Both degree of crosslink and state‐of‐mix are responsible for the dynamic mechanical properties in the case of WB 16. In addition, it was found that the tensile properties are controlled mainly by the plasticizing effect in the case of processing oil, but by the degree of crosslink in the cases of WB 16 and NS 60. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2474–2482, 2001     

3种加工助剂在CR中的性能对比

研究加工助RL16,WB16和AC617对CR胶料性能的影响.结果表明:加工助剂RL16或WB16与防焦剂DM并用时,可以提高CR胶料的硫化速度、抗焦烧性能和加工安全性,加工助剂AC617的抗焦烧性能不明显;3种加工助剂对CR硫化胶的物理性能影响不大.     

HEAT TRANSFER CHARACTERISTICS OF THREE PHASE FLUIDIZED BEDS

Heat transfer characteristics of two (liquid-gas, liquid-solid) and three (liquid-gas-solid) phase fluidized beds have been studied in a 15.2 cm-ID column fitted with an axially mounted cylindrical healer. Effects of gas velocity (0-12 cm/s). liquid velocity (0-16cm/s), particle size (1.7-8.0 mm) and liquid viscosity (0.001-0.039 Pa s) on heat transfer coefficient were determined. The heat transfer coefficient increased with fluid velocities and particle size and it decreased with liquid viscosity in two and three phase fluidized beds. The bed porosity at which the maximum heat transfer occurred decreased with particle size but increased with liquid viscosity. The coefficient were correlated in terms of experimental variables. Modified Nusselt number from the present and previous studies has been correlated with modified Prandtl and Reynolds numbers.     

Microstructure and properties of WB/Al nuclear shielding composites prepared by spark plasma sintering

In this paper, a novel nuclear shielding material capable of shielding neutrons and gamma rays, WB-reinforced Al (WB/Al) composites, was prepared by spark plasma sintering (SPS) process. The microstructure of the composites was characterized, and the effects of WB content, heat treatment and matrix type on the properties of the composites were discussed. The results demonstrate that the WB particles are uniformly dispersed in the aluminum matrix and formed a good binding interface with the matrix. WAl₁₂ as an interfacial reaction product is identified, and segregation of Si and Mg elements at the reinforcement/matrix interface occurs. The mechanical properties of the WB/Al composites are sensitive to the WB content. The hardness, elastic modulus and bending strength of the composites increase monotonously as the WB volume fraction increasing, up to 234%, 107% and 91.6% higher respectively than those of the monolithic 6061Al. However, the tensile strength reaches a peak point when the volume fraction is 20%. The effects of T6 treatment and matrix type are not pronounced, especially for the composites with high WB content. The thermal neutron and gamma ray shielding properties of the composites both increase with the increase of material thickness and WB content. The WB/Al composites developed in this work show good application prospects in the field of nuclear radiation protection, due to their good mechanical properties and well neutron and gamma-ray shielding performance.     

硅粉凝胶注模成型的研究

以硅粉为原料,通过对硅粉悬浮液的Zeta电位、粘度、分散性的测试,制备了固相体积比为50vol%硅粉的稳定悬浮液;通过调节引发剂过硫酸铵、催化剂N,N,N',N'-四甲基乙二胺(TEMED),制备了凝胶时间为1小时,干燥强度为7MPa的硅材料坯体。     

分散剂对釉料中Nano—ZnO分散性研究

通过对不同浓度C16-MADS、SDS和六偏磷酸钠3种分散剂对釉料中Nano—ZnO进行分散效果的研究,得出结论：0．7％（质量分数,下同）C16-MADS,4．00％纳米ZnO,粘度0．65;0．5％六偏磷酸钠,4．0％纳米ZnO,粘度0．95;0．8％SDS＋C16-MADS,4．0％ ZnO,粘度0．56。     

EFFECT OF SUBSTITUTING MgO FOR CaO ON PROPERTIES OF TYPICAL SODA-LIME GLASSES*

In base glasses containing (a) Na₂O 16, CaO 10, and SiO₂ 74% and (b) Na₂O14, CaO 12, and SiO₂ 74%, MgO was substituted in steps of 2% for CaO. The effects of the substitution on liquidus temperature, viscosity, fiber softening point, and the resistance of the glasses to dilute acid and to distilled water are described.