喷霜

喷霜又名喷出(blooming)，是橡胶加工过程中常见的质量问题，它是指未硫化胶或硫化胶中所含的配合剂迁移到表面并析出的现象。有时，这种喷出物呈霜状结晶物，故习惯上称“喷霜”。较多见的喷霜物为硫，因为硫黄是通用橡胶中应用最广泛的硫化剂，且在橡胶中的溶     

橡胶喷霜物的快速检测

用自制的橡胶喷霜快速检测箱（主要由薄层板、展开缸、展开剂、显色剂、加热器及荧光检测器组成）对橡胶制品及胶料喷霜物进行检测。经裂解一气相色谱验证，喷霜快速检测箱可快速、准确地定性检测出喷霜物中常用促进剂、防老剂和软化剂等有机配合剂的种类，为改进胶料配方、减少喷霜提供依据。     

橡胶表面喷霜物厚度的显微表征方法

借助扫描电子显微镜(SEM)和原子力显微镜(AFM)对橡胶表面喷霜物厚度进行表征。结果表明:SEM法从截面角度测试喷霜物厚度,统计多组厚度数据,以直方图的形式反映喷霜物厚度的分布情况,方法直观、结果客观;AFM法通过三维图像得出喷霜物厚度,适合喷霜物未完全覆盖橡胶表面且起伏高度差小于3μm的样品,方法简单、分辨率高。     

用场发射扫描电子显微镜-能谱仪分析胶料喷霜

用场发射扫描电子显微镜(SEM)-能谱仪(EDS)分析混炼胶和硫化胶的喷霜情况。结果表明:混炼胶中氧化锌和促进剂NS会导致不溶性硫黄转化为无定性结构而喷霜;随着停放时间延长,硫化胶中过量的促进剂NS以长方体规则结构喷霜。SEM-EDS可以分析喷霜物的结构、形貌和种类,为轮胎喷霜物的鉴定提供快捷、可靠的分析方法。     

橡胶制品喷霜的原因分析及预防措施

从配方设计、炼胶与硫化工艺等角度分析了造成橡胶制品半成品和成品喷霜的原因和有关机理，及其他因素对橡胶制品喷霜的可能影响，论述了采用不溶性硫黄或聚合硫黄代替普通硫黄，用促进剂DPTT代替促进剂TMTD，用低相对分子质量的聚合物增塑剂代替一般的油类软化剂，选择采用聚合型的防老剂RD，选择采用微观结构为片状、粒径小且径厚比大的填料改善抗喷霜性的有关原理，以及喷霜的综合预防措施。     

不溶性硫黄喷霜性能研究及评价方法

通过设定胶料的终炼工艺参数和停放条件,研究胶料中不溶性硫黄喷霜的原因。结果表明：胶料表面析出物基本为硫黄,由不溶性硫黄还原而来;采用所建立胶料的喷霜程度评价等级体系,包括各等级对应的照片,可以直观、快捷地表征不溶性硫黄的喷霜性能;适宜的终炼排胶温度和停放环境（温度）可以有效避免不溶性硫黄喷霜。     

气相色谱/质谱联用分析橡胶制品喷霜析出物

用气相色谱/质谱联用(GC/MS)对汽车门窗密封条、橡胶手套、白胶板、轮胎等喷霜析出物进行分析。从GC/MS总离子流色谱分析得出,橡胶制品喷霜析出物主要为防焦剂、促进剂、防老剂、防护蜡和硬脂酸等。GC/MS分离效果好,测试效率高,可以较准确地分析橡胶制品的喷霜析出物。     

石蜡喷霜机理

可能会喷霜的配合剂有萃取性防老剂和增粘剂。硫黄和石蜡的喷霜格外受到重视。对于这一问题,金子秀男作了简洁的论述: “喷霜”是指硫黄、石蜡、硬脂酸等可溶于橡胶的物质,随着温度的降低其溶解度下降而析出表面的现象。特别是硫黄等结晶性明显的物质,     

橡胶喷霜的成因及防止

喷霜在橡胶中是比较常见的现象。防止橡胶表面喷霜可以通过调整胶料配方、改进工艺规程、改善贮存条件等途经来实现。本文讨论了橡胶喷霜的成因，形式及其危害，并提出了防止橡胶喷霜应采取的措施和喷霜后的挽救办法。     

乙丙橡胶的喷霜问题

乙丙橡胶是非极性饱和橡胶,常会发生喷霜现象,在综合分析喷霜的形式、原因、危害等基础上,提出了具体的检验方法及解决和预防措施。     

橡胶防老剂RD性能改进的研究

通过对橡胶防老剂ＲＤ生成反应的基础研究，确定了两步法合成ＲＤ的工艺路线，优化了反应条件。改进后的产品与国外最新同类产品ＡｎｔｉｇｅｎｅＦＲ质量指标相符，在二、三、四聚体含量、软化点及外观等方面均有改善，在橡胶中的应用性能更加优越。     

Study of rubber-modified brittle epoxy systems. Part II: Toughening mechanisms under mode-I fracture

The toughening mechanisms in grafted-rubber concentrate (GRC), dispersed acrylic rubber (DAR), and Proteus rubber-modified brittle epoxy (i.e., highly crosslinked) systems are examined using scanning electron microscopy, optical microscopy and transmission electron microscopy techniques. The toughening of the GRC-modified brittle epoxy system is found to be due to cavitation of the GRC rubber particles, followed by formation of limited shear yielding when the crack propagates. Crack bifurcation and crack deflection are also observed in this system. Only crack bifurcation, crack deflection, and possibly crack/particle bridging mechanisms are operative in the DAR-modified brittle epoxy system. In the case of the Proteus rubber-modified system, the rubber appears to be rigid (T_g ≈ 28°C). As a result, the crack/particle bridging mechanism is not observed. Only crack deflection and crack pinning mechanisms are found. These observations are in agreement with the toughness measurement results (see Part I), which indicate that the GRC rubber provides the most effective toughening, followed by the DAR rubber, and then by the Proteus rubber. An approach for toughening brittle epoxies is also discussed.     

Effect of the blooming of chemical curatives on the cyclic fatigue life of natural rubber filled with a silanized silica nanofiller

When partly soluble chemical curatives are mixed with raw rubber, they migrate to the rubber surface, which can be detrimental to the rubber properties. Two rubber compounds with different amounts of curatives were prepared by mixing natural rubber with a high loading of precipitated amorphous white silica nanofiller. The silica surfaces were pretreated with bis(3‐triethoxysilylpropyl)‐tetrasulfide coupling agent to chemically adhere silica to the rubber. The chemical bonding between the filler and rubber was optimized via the tetrasulfane groups of bis(3‐triethoxysilylpropyl)‐tetrasulfide by adding accelerator and activator. The rubber compounds were cured and stored at ambient temperature for up to 65 days. One compound showed extensive blooming as a function of storage time. The cyclic fatigue life of the rubber vulcanizates was subsequently measured at a constant strain amplitude and test frequency at ambient temperature. The blooming of the chemical curatives reduced the cyclic fatigue life of the rubber vulcanizate by more than 100%. The migrated chemical curatives produced a thin layer approximately 15 μm in size beneath the rubber surface. When the rubber was stressed repeatedly in the fatigue test, cracks initiated in this layer and subsequently grew, causing the fatigue life of the vulcanizate to decrease. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

橡胶喷霜的防护研究进展

概述了橡胶(包括胶料和橡胶制品)喷霜的原因及机理,重点介绍了国内近20多年来橡胶喷霜防护研究的成果,并提出了今后的努力方向。     

Synthesis,characterization and electrochemical evaluation of anticorrosion property of a tetrapolymer for carbon steel in strong acid media

A novel tetrapolymer(TP) consisting of carboxylate, sulphonate, phosphonate and sulfur dioxide based comonomers was synthesized using Butler cyclopoymerization technique. The synthesized tetrapolymer was characterized using FTIR,1 H-NMR,~(13)CNMR and elemental analysis. The performance of the tetrapolymer as a corrosion inhibitor for St37 carbon steel in 15% HCl and 15% H_2SO_4 acid media was assessed using electrochemical impedance spectroscopy(EIS), linear polarization resistance(LPR), potentiodynamic polarization(PDP) and electrochemical frequency modulation(EFM) techniques. The influence of addition of a small amount of KI on the corrosion inhibition efficiency of TP was also assessed. Results obtained showed that the tetrapolymer moderately inhibited the corrosion of St37 steel in the acid media with protection efficiency of 79.5% and 61.1% at the optimum concentration of 1000 mg·L~(-1) studied in HCl and H_2SO_4 media respectively. On addition of 5 mmol·L~(-1) KI to the optimum tetrapolymer concentration, the protection efficiency was upgraded to 90.6% and 93.5% in HCl and H_2SO_4 environment, respectively. The enhanced performance of the polymer in the presence of KI is due to synergistic action deduced from synergism parameter(S1) which was found to be greater than unity.The tetrapolymer afforded the corrosion inhibition of St37 steel in the acid media by virtue of adsorption of the polymer molecules on the steel surface which was confirmed by ATR-FTIR analysis of the adsorbed film extracted from the steel surface. TP + KI formed complex with St37 steel surface in H_2SO_4 solution but not in HCl solution.     

Synthesis and characterization of a new polymer–drug conjugate with pH-induced activity

A well-defined, stimuli-responsive tetrapolymer with pH-responsive characteristics and targeting specificity has been synthesized by radical copolymerization of methacrylic acid, N-(2-hydroxypropyl)methacrylamide, methacryloyl glycylglycyl sulfamethoxazole, and N-(methacryloyl)glycylglycine 4-nitrophenyl ester. The structure and properties of tetrapolymer were investigated by NMR, FT-IR, UV–visible absorption, TEM and gel permeation chromatography. Incorporation of maleimide linker into tetrapolymer facilitates its conjugation with antibody fragments, as demonstrated by the solid-phase immunoassay experiments. The TEM image shows that tetrapolymer had self-assembled a spherical micelle with a diameter ranging from 50 to 150 nm. Altering the pH of the solution leads to a different extent of aggregation at pH 6.5–3.5, responding in accordance with the properties associated with the extracellular environment of solid tumors and endocytosis. Furthermore, fluorescence spectroscopy indicated a critical micelle concentration (CMC) of 1 mg/mL. Because of the solvation and ionization effects, the tetrapolymer showed considerably enhanced antibacterial activities against Escherichia coli in the presence of DMSO and the antibacterial activity increased with decreasing pH value.     

橡胶半成品和成品喷霜的成因及解决方法

综合分析了橡胶半成品和成品喷霜的原因并结合橡胶特性和各种配合剂的特性提出了喷霜的解决方法,对已喷霜的成品概括论述了相应的解决措施。     

橡胶部件不粘问题分析

分析了影响轮胎部件不粘的原因,最常见的原因是硫黄喷霜和部件存放时间过长。介绍了分析所需配备的实验仪器,主要有６０倍显微镜。红外光光谱仪和紫处分光光谱仪。提出了表面分析过程图。叙述了硫黄和非硫黄喷霜的鉴定步骤。还 引起部件不粘的表面物质产的原因。     

连续本体法耐热ABS树脂的开发

以N-苯基马来酰亚胺（NPMI）、丙烯腈（AN）、苯乙烯（SM）和二烯橡胶（BR）为原料,采用连续本体聚合技术合成了NPMI-AN-SM-BR四元共聚物。研究了NPMI用量、聚合温度、进料方式等对产品性能的影响。结果表明：随着NPMI用量的增加,共聚物的维卡软化点和热变形温度显著提高,熔体流动速率则有所下降。通过工艺条件和工艺配方的优化调整,获得了性能与目标牌号一致,某些性能甚至高于目标牌号的耐热ABS产品BH-102H和BH-202。利用HAAKE流变仪对其和相应目标产品的加工性能进行了横向比较,表明所开发材料的加工性良好,能够满足应用要求。     

Kinetics study of an acrylic tetrapolymer: Poly(IBMA–MMA–MAA–TBMA)

In this study, the polymerization kinetics and the molecular structure of the tetrapolymer poly[isobornyl methacrylate (IBMA)–methyl methacrylate (MMA)–methacrylic acid (MAA)–tert‐butyl methacrylate (TBMA)] were investigated. The relationships among the tetrapolymer composition, monomer conversion, and reaction time were studied. Kinetic equations of the four‐component copolymerization related to the mean sequence length, the run number, the reactivity ratio, and the monomer concentration were derived. The mean sequence length of the monomer IBMA increases with the reaction time and monomer conversion. However, those of the other three monomers remain an insignificant variation. Furthermore, the run number decreases rapidly at the end of polymerization. These results suggest that the slow polymerization rate of IBMA is due to its bulky side group. The mean sequence lengths of IBMA, MMA, MAA, and TBMA at the end of polymerization are 1.772, 1.304, 1.169, and 1.229, respectively. On the other hand, the run number of the prepared tetrapolymer is 70.25. The results of the mean sequence length, run number, and the single glass transition temperature suggest that the prepared tetrapolymer is a random copolymer. The molecular weight distribution of the prepared tetrapolymer is significantly affected by polymerization conditions. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 853–863, 2001