炭黑填充NR和S—SBR硫化胶动态性能及屈挠破坏性的研究

探讨炭黑种类及用量对天然橡胶（NR）和溶聚丁苯橡胶（S—SBR）硫化胶的耐屈挠破坏性及动态力学性能的影响。结果表明,随着炭黑N234、N330用量的增大,NR和S—SBR两种硫化胶的耐屈挠破坏性降低;随炭黑粒径增大,炭黑用量对两种硫化胶的耐疲劳破坏性的影响逐渐减小;NR硫化胶的耐初始疲劳破坏性明显优于S—SBR硫化胶,随屈挠次数的增加,两者间的差距逐渐减小。炭黑用量增加,NR和S—SBR硫化胶的损耗因子峰值（tanδmax）减小,高于10℃时（高弹态）的tanδ值增大,S—SBR较NR具有更好的抗湿滑性和相差无几的低滚动阻力。炭黑粒径减小,NR和S—SBR硫化胶的tanδmax减小,填充30质量份炭黑时,N660增强的两种硫化胶在0℃时tanδ值较高,60℃时最低,具有较好的动态性能。     

NR硫化胶的动态力学性能

采用无转子流变仪、橡胶加工分析仪、动态热机械分析仪研究了相对分子质量、炭黑用量、炭黑粒径、促进剂含量、氧化锌含量、硬脂酸含量和老化时间对NR硫化胶动态力学性能的影响。结果表明,0℃和60℃左右,低相对分子质量NR硫化胶的损耗因子(tanδ)略大于高相对分子质量NR硫化胶;随着炭黑用量的增加,硫化胶tanδ峰值减小,继续增加炭黑用量,NR硫化胶的炭黑网络结构增强,tanδ不断变大;随着炭黑粒径的增加,NR硫化胶的玻璃化转变温度(T_g)略向高温方向偏移,而处在高弹态后,硫化胶的tanδ随着炭黑粒径的增大而减小。     

二苯基硅烷改性白炭黑对SBR性能的影响研究

以二苯基硅烷作改性剂制备了改性白炭黑，研究了二苯基硅烷用量对白炭黑补强SBR性能的影响。结果表明，加入二苯基硅烷后，SBR胶料焦烧时间、工艺正硫化时间及最高转矩均明显增大，最低转矩逐渐减小；加入二苯基硅烷对SBR硫化胶力学性能有一定的改善作用；当用量为2份时，SBR硫化胶综合力学性能较好。随着二苯基硅烷用量的增大，SBR硫化胶0℃损耗因子tanδ略有增大，60℃损耗因子tanδ略有减小；白炭黑在SBR中的附聚体尺寸明显降低；当其用量为1份时，白炭黑附聚体尺寸达到最小值9.46μm。     

配方因素对CR硫化胶损耗因子的影响

研究配方因素对CR硫化胶损耗因子(tanδ)的影响。结果表明,在硫醇调节型CR中并用适量NR或硫调节型CR可降低硫化胶的tanδ值;在硬度相近的前提下,采用细粒子炭黑补强的CR硫化胶tanδ值低于采用粗粒子炭黑补强的CR硫化胶;加入增塑剂后,CR硫化胶的tanδ值增大,加入油酸丁酯和增塑剂TP95的硫化胶tanδ值增幅较小;加入少量硫黄可降低CR硫化胶tanδ值;在填充白炭黑的CR胶料中加入偶联剂可使硫化胶tanδ值增大。     

微生物脱硫胶粉/天然橡胶共混胶的性能

用微生物提取物脱硫改性胶粉(RP),考察了脱硫胶粉(DRP)用量对其与天然橡胶(NR)共混胶的硫化性能、动态力学性能以及物理机械性能的影响,并与RP/NR共混胶进行了对比.结果表明,DRP的加入提高了其与NR的交联程度;DRP/NR混炼胶的Payne效应较RP/NR混炼胶小;随着DRP用量的增加,DRP/NR硫化胶的储能模量降低,损耗因子增大;DRP/NR硫化胶的物理机械性能随着DRP用量的增加而下降,但优于RP/NR硫化胶;DRP在NR中的分散性较RP均匀,与NR的界面结合更强.     

Si 69在炭黑填充NR/BR/NBR共混物中的应用

在炭黑填充NR／BR／NBR共混物中加入Si 69，共混物硫化速度降低、物理机械性能提高；Si 69用量为4份时，硫化胶的综合性能最佳。将140℃下用Si 69处理30min后的炭黑加入NR／BR／NBR共混物，可降低硫化胶在65℃下的tan 6值，表明材料的滚动阻力下降。     

白炭黑用量对NBR/BR的动态力学性能和Payne效应的影响

研究不同白炭黑用量的丁腈橡胶/顺丁橡胶并用胶的动态力学性能。结果表明:随着白炭黑用量的增大,白炭黑与橡胶基体间的相互作用增强,混炼胶的Payne效应增大;随温度升高,混炼胶储能模量(G′)减小,损耗因子(tanδ)先增大后减小,硫化胶的G′变化不大,tanδ先增大后减小;随白炭黑用量增大,混炼胶的G′增大,tanδ在低温时增大,高温时减小,硫化胶的G′和tanδ增大。     

环氧大豆油改性白炭黑对天然橡胶性能的影响

采用环氧大豆油(ESO)对白炭黑进行改性,研究ESO改性白炭黑对天然橡胶(NR)性能的影响。结果表明:采用ESO对白炭黑进行改性,ESO分子成功接枝到白炭黑粒子上;ESO改性白炭黑可以降低NR混炼胶的门尼粘度和动态模量,改善其加工性能;提高NR硫化胶的物理性能,降低NR硫化胶60℃时的损耗因子(tanδ)值、提高0℃时的tanδ值,从而降低动态生热、提高抗湿滑性能。     

白炭黑在NR／BR／SSBR并用胶中的应用

研究了白炭黑／炭黑填充NR／BR／SSBR并用胶的物理性能，用橡胶加工分析仪(RPA2000)分析并用胶硫化性能和动态粘弹性的变化规律。结果表明，炭黑和白炭黑总量固定，白炭黑的用量增大时，并用胶的物理性能略有下降，固特里奇压缩疲劳性能改善，并用胶的硫化速度减缓，且t90和t10的变化与白炭黑的用量呈线性关系；60℃的tan8值随白炭黑用量增大则呈下降趋势，即硫化胶的滚动阻力降低。     

白炭黑在NR/BR/SSBR并用胶中的应用

研究了白炭黑／炭黑填充NR／BR／SSBR并用胶的物理性能，用橡胶加工分析仪(RPA2000)分析并用胶硫化性能和动态粘弹性的变化规律。结果表明，炭黑和白炭黑总量固定．白炭黑的用量增大时，并用胶的物理性能略有下降，固特里奇压缩疲劳性能改善，并用胶的硫化速度减缓，且t90和t10的变化与白炭黑的用量呈线性关系；60℃的tanδ值随白炭黑用量增大而呈下降趋势，即硫化胶的滚动阻力降低。     

Fly‐ash particles and precipitated silica as fillers in rubbers. II. Effects of silica content and Si69‐treatment in natural rubber/styrene–butadiene rubber vulcanizates

This article explored the possibility of using silica from fly‐ash particles as reinforcement in natural rubber/styrene–butadiene rubber (NR/SBR) vulcanizates. For a given silica content, the NR : SBR blend ratio of 1 : 1 (or 50 : 50 phr) exhibited the optimum mechanical properties for fly‐ash filled NR/SBR blend system. When using untreated silica from fly‐ash, the cure time and mechanical properties of the NR/SBR vulcanizates decreased with increasing silica content. The improvement of the mechanical properties was achieved by addition of Si69, the recommended dosage being 2.0 wt % of silica content. The optimum tensile strength of the silica filled NR/SBR vulcanizates was peaked at 10–20 phr silica contents. Most mechanical properties increased with thermal ageing. The addition of silica from fly‐ash in the NR/SBR vulcanizates was found to improve the elastic behavior, including compression set and resilience, as compared with that of commercial precipitated silica. Taking mechanical properties into account, the recommended dosage for the silica (FASi) content was 20 phr. For more effective reinforcement, the silica from fly‐ash particles had to be chemically treated with 2.0 wt % Si69. It was convincing that silica from fly‐ash particles could be used to replace commercial silica as reinforcement in NR/SBR vulcanizates for cost‐saving and environment benefits. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Naturally occurring halloysite nanotubes for enhanced durability of natural rubber/ethylene propylene diene monomer rubber vulcanizate

A facile approach of using halloysite nanotubes (HNTs) was proposed to address the durability performance demands of natural rubber (NR)/ethylene propylene diene monomer rubber (EPDM) blends and to protect them from the deleterious effects of the service environment including ozone, chemicals, abrasion, and cyclic loading. The introduction of HNTs substantially improved the stability of NR/EPDM when exposed to ozone (over fourfold enhancement with the addition of 5 phr HNTs). Moreover, the HNT-filled NR/EPDM vulcanizates offered approximately 66% reduction in the solvent-mediated swelling in comparison to the unfilled sample. Fatigue life studies showed that the HNT-reinforced NR/EPDM composite could withstand 30% more cycles to failure than the un-reinforced NR/EPDM blend. The effect of various HNT loading on the morphological, mechanical, physical, and rheological properties of nanocomposite vulcanizates based on NR/EPDM was also investigated. The morphological investigations revealed that the introduction of HNT into the NR/EPDM rubber matrix caused a rough morphology in fracture surface and a well-dispersed structure was obtained with the addition of up to 5 phr of HNTs. These findings were further supported by rheological, mechanical, and thermodynamical results.     

Fly ash particles and precipitated silica as fillers in rubbers. I. Untreated fillers in natural rubber and styrene–butadiene rubber compounds

In this study, we investigated the effects of untreated precipitated silica (PSi) and fly ash silica (FASi) as fillers on the properties of natural rubber (NR) and styrene–butadiene rubber (SBR) compounds. The cure characteristics and the final properties of the NR and SBR compounds were considered separately and comparatively with regard to the effect of the loading of the fillers, which ranged from 0 to 80 phr. In the NR system, the cure time and minimum and maximum torques of the NR compounds progressively increased at PSi loadings of 30–75 phr. A relatively low cure time and low viscosity of the NR compounds were achieved throughout the FASi loadings used. The vulcanizate properties of the FASi‐filled vulcanizates appeared to be very similar to those of the PSi‐filled vulcanizates at silica contents of 0–30 phr. Above these concentrations, the properties of the PSi‐filled vulcanizates improved, whereas those of the FASi‐filled compounds remained the same. In the SBR system, the changing trends of all of the properties of the filled SBR vulcanizates were very similar to those of the filled NR vulcanizates, except for the tensile and tear strengths. For a given rubber matrix and silica content, the discrepancies in the results between PSi and FASi were associated with filler–filler interactions, filler particle size, and the amount of nonrubber in the vulcanizates. With the effect of the FASi particles on the mechanical properties of the NR and SBR vulcanizates considered, we recommend fly ash particles as a filler in NR at silica concentrations of 0–30 phr but not in SBR systems, except when improvement in the tensile and tear properties is required. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2119–2130, 2004     

Fatigue resistance of silica‐filled natural rubber vulcanizates: comparative study of the effect of phosphorylated cardanol prepolymer and a silane coupling agent

The fatigue resistance of silica‐filled natural rubber (NR) mixes modified with phosphorylated cardanol prepolymer (PCP) was studied in comparison with similar compositions without PCP and with those containing the same dosage of a silane coupling agent (Si‐69). Considerable improvement in the fatigue resistance was observed for the PCP‐modified NR vulcanizate containing 20 phr of silica compared with the unmodified and Si‐69 modified vulcanizates. In addition, the tear strength of the PCP‐modified NR vulcanizate was higher than that of the others. Atomic force microscopy and the scanning electron microscopy of the vulcanizates showed better dispersion of silica particles in the NR matrix in the presence of PCP than in the unmodified and Si‐69‐modified NR vulcanizates. It is assumed that, at a dosage of 5 phr, PCP functions as a coupling agent between NR and the silica particles thereby improving the filler dispersion and consequently the mechanical properties of the vulcanizate. Copyright © 2005 Society of Chemical Industry     

NR/TPI并用胶半有效硫化体系的研究

考察了促进剂NS用量、硫黄用量和硫载体DTDM对NR/反式-1,4-聚异戊二烯(TPI)并用胶性能的影响.结果表明,在半有效硫化体系中,硫黄用量1.2～1.4份,促进剂NS用量1.4～1.6份时,NR/TPI(80/20)并用胶可以获得良好的综合性能.NR/TPI中使用DTDM后,硫化速度虽略有降低,但胶料焦烧时间延长,加工安全性提高,硫化胶物理机械性能、疲劳性能、滚动阻力以及耐老化性能均得到改善,这与DTDM在NR中的应用相似.     

天然橡胶/固相法改性纳米碳酸钙复合材料的微观形态与力学性能

研究了天然橡胶（NR）／硬脂酸包覆型纳米碳酸钙（CCR）复合材料和NR／固相法改性纳米碳酸钙（M-CCR）复合材料的微观形态、力学性能、耐老化性能和热稳定性能等。结果表明,与CCR相比,M—CCR在NR中的分散性更好,界面结合形态得到了改善;NR／M—CCR复合材料的力学性能、耐老化性能和热稳定性能显著提高,且当M—CCR用量少于10份时,NR／M—CCR复合材料的综合性能最佳。     

高耐磨炭黑填充型粉末NR研究(Ⅲ)硫化胶的物理机械性能

研究了高耐磨炭黑(N330)填充型粉末天然橡胶[P(NR/N330)]硫化胶的物理机械性能.结果发现炭黑乳化剂、炭黑、操作油和包覆剂的用量及玻璃化转变温度对P(NR/N330)硫化胶的物理机械性能的影响比较明显.在适宜的粉末化条件下制备的P(NR/N330),其硫化胶的物理机械性能优于天然胶乳与炭黑的简单共沉胶(ENR/N330),而300%定伸应力则低于块状NR/N330机械混炼胶(MNR/N330).P(NR/N330)硫化胶拉伸断面形貌的SEM分析表明,包覆剂在用量为15份时,与NR基体形成互锁结构;DSC分析表明,二者部分相容,因此硫化胶具有较好的物理机械性能.     

TBIR改性NR硫化胶的研究

研究了两种牌号反式-1,4-丁二烯-异戊二烯共聚橡胶(TBIR)改性天然橡胶(NR),结果表明,10~50份TBIR与NR共混,并用胶焦烧时间(t10)和工艺正硫化时间(t90)略有延长。相比NR硫化胶,NR/TBIR并用硫化胶力学强度保持在较高范围,屈挠疲劳性能大幅度提高,其中NR/TBIR-20=50/50硫化胶一级屈挠疲劳寿命可提高28.6倍,六级屈挠疲劳寿命可提高11.9倍。DMA结果表明,NR与TBIR具有优异的相容性。RPA及DMA 结果均表明NR/TBIR并用硫化胶具有更低的滚动阻力。综合可知,TBIR是一种高性能的合成橡胶新材料,可显著改善NR的综合性能。     

白炭黑/炭黑复合填充对NR性能的影响

在白炭黑和炭黑填料总量一定的情况下,研究了不同白炭黑/炭黑配比对NR性能的影响。结果表明,白炭黑用量增加,NR硫化速率下降,体系中炭黑填料网络被破坏且白炭黑-橡胶间较弱的相互作用也会对NR硫化胶力学性能产生一系列影响。DMA结果表明,加入20~25份白炭黑对提高硫化胶的抗湿滑性和降低滚动阻力最为有效。