白炭黑粒径对湿法混炼天然胶乳/白炭黑胶料性能的影响

在液相状态下,利用球磨机对白炭黑进行研磨,制备白炭黑水分散体,研究分散体中白炭黑粒径对湿法混炼天然胶乳/白炭黑胶料性能的影响。结果表明,不同粒径白炭黑胶料的性能差异较大,当白炭黑聚集体粒径为9.4μm时,胶料的综合性能最佳。     

新型抗沉淀剂KM-S的应用研究

研究新型抗沉淀剂KM-S研磨碳酸钙和半补强炭黑以及用于胶乳混合分散体的分散效果。结果表明:抗沉淀剂KM-S具有优良的分散作用,研磨碳酸钙能显著减小分散体沉降量;研磨半补强炭黑,分散体总固体质量分数最高可达到0.30;研磨混合分散体配制的胶乳粘度低、稳定性好,制备的气球物理性能优良。     

天然胶乳/丁基胶乳并用胶乳的性能研究

采用完全随机化试验方法,研究天然胶乳/丁基胶乳并用比和硫化强化包用量（以干量计）对并用胶乳及其硫化胶膜性能的影响。结果表明：并用胶乳的粘度随着停放时间的延长而逐渐增大;并用胶乳硫化胶膜的气密性随着丁基胶乳占比的增大而呈提高趋势;当天然胶乳用量为100份、丁基胶乳用量为5.42份、硫化强化包用量为2.65份时,并用胶乳硫化胶膜的拉伸强度可达到24 MPa左右。     

胶乳制品配合剂分散体的制备

胶乳是高聚物粒子分散在水介质中所形成的具有一定稳定性的胶体分散体系。在天然胶乳或合成胶乳的制品生产工艺中,都要预先把非水溶性的固体粉末状化学助剂(配合剂)制备成水分散体后才能加入胶乳中进行配合、预硫化,使胶乳成为配合胶乳或预硫化胶乳方,能制造出不同要求和性能的各种胶乳制品,以满足国民经济各部门和外贸出口的需要。生产制造优质的胶乳制品,首先要选择高质量胶乳,还要设计符合产品使用、贮存性能的产品配方。在配方中,各种配合剂的水分散体制备质量、水分散体的配方、设备对生产胶乳制品来说是一个非常重要的工序,把非水溶性…     

溴化丁基橡胶/酚醛硫化树脂复合胶乳的制备与硫化

通过溶液乳化法制备了固含量为9.3%的溴化丁基橡胶/酚醛硫化树脂复合胶乳.以海藻酸钠为膏化剂对复合胶乳进行了膏化浓缩,研究了膏化剂用量对膏化时间、胶乳固含量和胶乳粒径的影响,结果表明膏化浓缩胶乳粒径较大,膏化周期较长,一般需半个月左右才能得到实用的浓缩胶乳.采用扫描电镜观察了复合胶乳干胶膜的断面形貌,发现大粒径的膏化胶乳成膜后胶粒间可以较好地融合.通过涂布、烘干和硫化等工艺制备了厚度为0.60 mm的复合胶乳硫化膜片,并测试了硫化膜片的力学性能和H2渗透性能,结果表明硫化膜片的力学性能较好,其H2渗透率较低,为天然橡胶的9.64%、氯丁橡胶的71.3%.     

高能球磨法制备纳米赤铁矿矿物颜料水分散体

以赤铁矿为原料,马来酸酐-醋酸乙烯酯共聚物PMV为分散剂,采用高能球磨法制备纳米级赤铁矿颜料水分散体,讨论了研磨时间、研磨介质以及分散剂用量等对分散体的粒径和Zeta电位的影响。结果表明,采用行星式球磨仪在球磨机转速为500 r/min,球磨时间为5 h,分散剂用量为0.25 g/g颜料,研磨介质为直径2 mm和0.5 mm锆珠的质量比为3∶2时,能获得粒径大小为230 nm的赤铁矿颜料水分散体,具有一定的粒径分散稳定性。     

纳米SiO2改性天然胶乳的制备及其性能研究

采用SDS先将纳米SiO2处理成20％稳定的分散体后再添加到天然胶乳中，着重研究了纳米SiO2的用量对天然胶乳的胶体性能及其硫化胶膜力学性能的影响。结果表明：纳米SiO2的用量在3－4份时可改善天然胶乳的胶体性能及其胶膜的力学性能，尤其是耐撕裂性能和耐老化性能的改善效果更为突出。     

BIIR/酚醛硫化树脂复合胶乳膏化浓缩工艺的研究

采用膏化浓缩法对BIIR/酚醛硫化树脂复合胶乳进行浓缩,研究适宜的膏化浓缩工艺条件.结果表明,采用膏化浓缩法,以海藻酸钠为膏化剂,可对BIIR/酚醛硫化树脂复合胶乳进行浓缩,浓缩后胶乳粒径明显增大,但可正常使用;膏化剂用量越大,膏化浓缩速度越慢,膏化自然终止时胶乳固形物质量分数越小,膏化剂与体系内水的质量比为0.1%～0.2%时较合适.     

不同割龄RRIM600橡胶树胶乳组分及性能的研究

研究割龄3,13,20,24和28年5种RRIM600橡胶树天然胶乳粒径、生胶性能、混炼胶硫化特性及硫化胶物理性能。结果表明,割龄28年的橡胶树所得天然胶乳平均粒径最小,胶粒分布范围较窄,分散性较好;割龄20年的橡胶树生胶的朝一阵初值和门尼粘度较大,割龄20和28年的橡胶树硫化胶的拉伸强度和撕裂强度较大。     

硅藻土在乳胶丝胶乳中的应用研究

研究硅藻土在乳胶丝胶乳中的应用。将硅藻土配制成水相分散体后再加入到胶乳中,胶乳经预硫化后生产乳胶丝。结果表明:硅藻土作为功能性填料用于乳胶丝生产,可满足生产工艺要求,乳胶丝的300%定伸应力、拉伸强度、拉断伸长率、施瓦兹值和耐老化性能明显提高,生产成本降低。硅藻土是乳胶丝良好的补强填充剂。     

The effect of pressure on carbon black/elastomer powders. IV. Comparison of press-cured powders containing vulcanizing agents with mill-mixed compounds

SBR latex was compounded with six different types of carbon black (SRF, FEF, HAF, SAF, HEB, and HCC-I) and vulcanization ingredients in aqueous dispersion by means of a dispersing agent. The particle size of the carbon black agglomerates in aqueous dispersion was estimated from turbidity and light scattering measurements. It was found that the size of the aggregates is by far larger than the average particle size of the SBR-latex used. The latex mixture containing carbon black and vulcanization ingredients was spray-dried to a fine-sized powder of an average particle size of 0.25 mm; this powder was subsequently vulcanized without the action of shear forces at a pressure of 200 bar. It was the aim of this study to answer the question whether latex-stage compounded vulcanizates can be reinforced without applying shear forces, if only the distribution of the carbon black in the compound is sufficiently good. The tensile strength was used for judging reinforcement; the quality of the carbon black dispersion was estimated by means of the Cabot rating method. The carbon black dispersion in the compounded powders proved to be excellent with fine-sized carbon blacks and was in the order of A 1 and B 2 of the Cabot scale. Scanning electron micrographs of the fracture zones and transmission electron micrographs on ultrathin cuts showed, however, differences in the microdispersion of the carbon blacks between powder-and mill-mixed compounds. A comparison of the mechanical properties of powder-and mill-mixed compounds yielded partially comparable tensile values for the powder compounds up to 20 MN/m², but strikingly high hardness, elongation set and a pronounced stress-softening after repeated deformation (Mullins-effect).     

Contribution of hydrogen and/or covalent bonds on reinforcement of natural rubber latex films with surface modified silica

A macromolecular coupling agent containing hydrophilic and hydrophobic groups is made to react with precipitated silica. Interfacial interactions between  OH groups of silica and  COOH groups of macromolecule are found to be created through either hydrogen bonds alone or through hydrogen bonds and covalent bonds. Aqueous dispersions of unmodified and modified silica are prepared and the colloidal stability and particle size distribution of the dispersions are observed. The dispersions at neutral pH are incorporated into vulcanized/unvulcanized natural rubber latex. The formation of hydrogen bonds and/or covalent bonds is studied via FTIR spectroscopy and their contribution in encouraging filler‐rubber interactions is emphasized through mechanical and swelling properties. Uniform distribution and dispersion of modified filler particles throughout the rubber matrix is confirmed by the microstructures of the latex films cast from filler added natural rubber latex. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40380.     

两种品系天然橡胶的结构与性能研究

通过对比两种品系（热研7—33—97和热研8—79）的天然胶乳中橡胶粒子的粒度、生胶理化性能、相对分子质量及其分布以及硫化胶的性能，研究了两种品系天然橡胶的结构与性能。结果表明，热研7—33—97的胶乳粒度比热研8—79的小，胶粒分布窄；热研8—79的相对分子质量分布较热研7—33—97宽，其力学性能、耐老化性能及硫化胶稳定性均好于热研7—33—97。     

NR/高岭土复合材料的制备及其硫化胶的力学性能

通过NR胶乳与高岭土悬浮液混合以凝聚共沉法制备填充型NR,并研究高岭土的结构、平均粒径和填充量等对其硫化胶力学性能的影响。结果表明,片状和粒径较小的高岭土填充的NR硫化胶有较高的力学性能,且在填充量达200份时,仍保持较高的力学性能。TEM观察表明,高岭土在凝聚法高岭土填充NR的硫化胶中与NR基体结合紧密,界面模糊。     

Comparative study of the elasticity and permeability of vulcanized films made with skim and cream natural rubber latex

The purpose of this study was to gain a clearer picture of the structure and properties of vulcanized films made with skim and cream latex from Hevea brasiliensis. The two properties targeted for this study were the elasticity of the films and their permeability to acetone. Surface characterization by atomic force microscopy revealed that vulcanization substantially modified the structure of the films compared to unvulcanized films. Unlike unvulcanized films, particle identity was retained in the vulcanized films made with cream latex, even after 4 weeks of aging. In addition, skim latex gave vulcanized films with greater elasticity than those obtained with cream latex. On the basis of the structural characterization carried out on the latex and films and information from the literature, the greater elasticity of the skim films arose from more entanglements between polyisoprene chains and associations between proteins. Despite differences in the structure, the acetone permeability was very similar for skim and cream vulcanized films. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Synthesis and characterization of urethane/acrylate composite latex

Polyurethane dispersion and urethane/acrylate composite latex were synthesized and characterized by using a particle size analyzer, gel permeation chromatograph (GPC), Fourier transform infrared spectroscopy coupled with attenuated total reflectance (FTIR‐ATR), dynamic mechanical analysis (DMA), and instron test machine. The amount of solvent and dimethylolpropionic acid (DMPA) used during synthesis of polyurethane resin straightway affected the average particle size and stability of aqueous polyurethane dispersion. The particle size of polyurethane dispersion had nothing to do with that of composite latex. FTIR‐ATR analyses displayed both air‐facing and substrate‐facing surfaces, containing more polyurethane component than the average composition. Some crosslinking reactions occurred in preparing urethane/acrylic composite latex, as indicated by FTIR analyses and solvent extraction. DMA demonstrated three glass transitions for the film from composite latex. Instron tests exhibited better film performance properties for the composite latex than for the corresponding blend latex. A possible particle growth mechanism for preparing urethane/acrylate composite latex was proposed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1620–1628, 2002; DOI 10.1002/app.10526     

Green preparation and physical properties of maleated sulfur-prevulcanized natural rubber

The maleated sulfur-prevulcanized natural rubber (M-SPNR) was prepared from grafting maleic anhydride (MA) onto SPNR latex particle by using benzoyl peroxide as an initiator. Natural rubber latex particle was vulcanized first, and then it was maleated to M-SPNR. The average particle size of M-SPNR was greater than that of SPNR possibly due to the formation of aggregate after addition of MA. The symmetric (strong) and asymmetric (weak) carbonyl stretching vibrations of succinic anhydride rings were confirmed by ATR–FTIR at 1,780–1,784 and 1,854?cm^?1, respectively. The swelling ratios of M-SPNR latex film decreased with increasing MA contents. The tensile strength, modulus, hardness, and elongation at break of SPNR latex film dramatically increased after grafting with MA. Due to the reduction of double bond, the thermal stability of M-SPNR film was better than that of SPNR. The environmental friendly M-SPNR would be further applied as a compatibilizer between NR and biopolymer.     

白炭黑粒径对天然橡胶/白炭黑湿法混炼胶性能的影响

通过使用球磨机在液相状态下对白炭黑进行研磨,可得到4种不同粒径白炭黑。采用湿法混炼工艺,将4种不同粒径的白炭黑与天然乳胶进行混合,制备出天然橡胶/白炭黑复合材料。对此种类型复合材料性能测定结果表明:用4种不同粒径的白炭黑制备的复合材料性能呈现出较大差异,当白炭黑粒径为9.4um,复合材料表现出最佳的综合性能。     

研磨改性废轮胎热解炭黑及其应用研究

本文主要研究采用研磨的方法改性CBp,并将其应用到丁苯橡胶中,对比考察了不同研磨时间的CBp、未改性CBp、N774的粒径分布差异及在丁苯橡胶中的性能差异。研究结果表明：研磨的方法可有效减小CBp的粒径,有助于其在橡胶中更好的分散,且研磨时间越长,炭黑粒子粒径越小,门尼粘度越大,扭矩差越大。研磨后的CBp补强的丁苯橡胶的拉伸强度、撕裂强度、300%定伸强度、硬度得到有效提高,综合改性效果良好。