淀粉/天然橡胶复合材料的结构与热稳定性研究

将淀粉进行糊化改性,将改性淀粉在乳液状态下与天然胶乳共混,制备淀粉/天然橡胶复合材料。利用扫描电镜(SEM)和热重分析(TG)表征复合材料的结构,并测定了其力学性能。研究结果表明:淀粉经糊化后,淀粉粒子在天然橡胶中分散均匀,粒径明显减小,复合材料的热稳定性和力学性能明显提高。     

淀粉/天然橡胶复合材料的研究

将淀粉进行糊化改性,将改性淀粉在乳液状态下与天然胶乳共混,制备淀粉/天然橡胶复合材料。用X-射线衍射（XRD）、差示扫描量热仪（DSC）和扫描电镜（SEM）表征复合材料的结构,并测定了其力学性能。研究结果表明：淀粉经糊化后,复合材料中淀粉粒子的结晶结构消失,粒子在天然橡胶中分散均匀,粒径明显减小。随着淀粉含量的增加,复合材料的硬度、定伸应力、拉伸强度和撕裂强度随之提高,且当其质量分数在20%时,复合材料的综合力学性能最佳。     

改性纳米炭黑增强丁苯胶乳及其在轮胎修补液中的应用

将炭黑N 220与对苯乙烯磺酸钠(NaSS)在流变仪中共混制得了改性纳米炭黑,用其配成水悬浮液与丁苯胶乳(SBRL)混合制备了纳米炭黑增强SBRL,用场发射透射电子显微镜观察了改性炭黑在SBRL中的分散情况,并对改性炭黑增强SBRL进行了薄膜拉伸和实车试验.结果表明,炭黑经NaSS改性后被NaSS包覆,在水中能够均匀分散,其粒径为90 nm,而普通炭黑在水中的粒径为238 nm;改性炭黑在SBRL中分散均匀;随着改性炭黑用量的增加,增强胶乳薄膜的拉伸强度明显提高,扯断伸长率明显低于未增强胶乳薄膜,但仍是未改性炭黑增强胶乳薄膜的3倍;改性炭黑增强SBRL制备的修补液修补强度明显大于未增强SBRL制备的修补液.     

对乙烯苯磺酸钠改性炭黑母炼胶的制备及性能

采用固相原位聚合接枝方法制备了对乙烯苯磺酸钠（NASS）改性的亲水性纳米炭黑。热重分析结果表明,NASS成功地接枝到炭黑表面,其接枝率为2．5％。水分散性测试结果表明,改性炭黑在水介质中分散稳定。扫描电子显微镜照片表明,改性炭黑以聚集体尺寸均匀分散于橡胶基体中。改性炭黑填充的天然胶乳硫化胶的物理性能有了较大幅度的提高,其中撕裂强度提高了160％。     

乳液共混法制备天然橡胶复合材料研究进展

天然橡胶的应用十分广泛,在其应用过程中,一般需要通过共混改性制备综合性能更加优异的天然橡胶复合材料。本文总结了近年来国内外使用乳液共混法制备天然橡胶复合材料的研究进展。介绍了天然橡胶与炭黑、粘土、白炭黑、碳纳米管、石墨烯等填料乳液共混的新方法。对比了乳液共混法及传统机械共混法制备的橡胶复合材料在加工流程、填料分散情况、材料力学性能等方面的差异;说明了乳液共混法制备天然橡胶复合材料的优势。并对乳液共混法的发展前景进行了展望。     

硅烷偶联剂对纳米SiO2／NR复合材料结构与性能的影响

用硅酸钠制备纳米SiO2乳液,用氯化铵控制粒径大小,然后与天然胶乳共混共沉制备出SiO2／NR复合材料。采用SEM对SiO2／NR复合材料断面进行分析,观察SiO2粒子大小和形态,并对其力学性能进行测试。结果表明,经过硅烷偶联剂处理的纳米SiO2在复合材料中分散均匀,力争性能较好。     

射流胶乳混合法天然橡胶复合材料的制备及性能研究

用射流胶乳混合法制备天然橡胶(NR)复合材料,并对复合材料性能进行研究。先用超声空化作用将炭黑团聚体破碎、切割、分散在水中制得炭黑悬浮液,然后在高速射流场中将炭黑微观分散到天然胶乳中制成NR复合材料。结果表明:与传统干法混炼工艺相比,射流胶乳混合工艺可以使炭黑更均匀地分散到NR基体中;射流胶乳混合工艺制备的复合材料硫化时间缩短,硫化程度增大,撕裂强度提高78%,回弹值提高20%,DIN磨耗量减小33%。     

乳液共混法制备白炭黑/乳聚丁苯橡胶复合材料及其性能研究

采用乳液共混法制备白炭黑/乳聚丁苯橡胶（ESBR）复合材料,研究ESBR胶乳破乳的影响因素、机理和动力学过程以及复合材料性能。结果表明：添加白炭黑或改性白炭黑的ESBR胶乳使用饱和氯化钠溶液的破乳效果改善;ESBR胶乳的絮凝程度随着饱和氯化钠溶液用量的增大而增大,破乳后期破乳速率迅速增大;破乳机理是以无机粒子为吸附中心的熵减最小化;乳液共混法制备的白炭黑/ESBR复合材料的拉伸强度比传统机械共混法制备的白炭黑/ESBR复合材料降低,耐磨性能不具优势,但低温抗湿滑性能明显改善。     

β-环糊精包合作用下甲基丙烯酸甲酯聚合物对天然胶乳的改性

以甲基丙烯酸甲酯/β-环糊精包合物为反应单体、偶氮二异丁腈为引发剂,在80℃下乳液聚合8 h制备了亲水性聚合物聚(甲基丙烯酸甲酯-β-环糊精)。将制得的聚合乳液用于共混改性天然胶乳,分析了共混乳液的相容性并与聚甲基丙烯酸甲酯与天然胶乳的相容性进行了对比。结果表明,由于β-环糊精外腔的羟基与天然胶乳外层的亲水磷脂蛋白层的相互作用,从而有效改善了聚甲基丙烯酸甲酯与天然胶乳的相容性; 通过力学性能、原子力显微镜以及耐热老化性能的分析测试发现,改性后共混乳胶膜的力学性能、表面形貌以及耐热老化性能均得到较大程度的改善。     

多壁碳纳米管改性航空轮胎橡胶材料的制备方法

正由中国民航大学申请的专利(公开号CN105482175A,公开日期2016-04-13)"多壁碳纳米管改性航空轮胎橡胶材料的制备方法",涉及的多壁碳纳米管改性航空轮胎橡胶材料的制备方法为:将多壁碳纳米管分散在阴离子表面活性剂水溶液中获得悬浮液,在悬浮液中加入天然胶乳,经过共混乳液的絮凝共沉和过滤干燥,得到由多壁     

木质素用量对乳液共沉天然橡胶性能的影响

采用共沉方法制备天然橡胶/木质素复合材料,研究了复合材料和炭黑胶料的性能以及木质素用量对天然橡胶性能的影响。结果表明,加有木质素的胶料,随着木质素用量的增加,复合材料的门尼粘度逐渐上升,炭黑胶料的最低转矩(ML)增大,最高转矩(MH)下降,正硫化时间(tc90)延长,焦烧时间(ts1)缩短,炭黑分散性变差,胶料的加工安全性、耐磨性及耐老化性变差,硫化胶的定伸应力降低。当木质素用量在20份以内时,硫化胶的拉伸强度和撕裂强度提高。     

降低负重轮天然橡胶基复合材料生热的研究状况

概述负重轮天然橡胶(NR)基复合材料的生热原理及表征方法,重点介绍交联结构和填料包括炭黑、硅烷偶联剂改性白炭黑、新型碳材料氧化石墨烯和多壁碳纳米管对复合材料生热影响的研究状况。指出将新型碳材料部分取代炭黑,采用胶乳共沉法制备新型碳材料母胶有利于将新型碳材料均匀分散在NR基复合材料中,在有效提高NR基复合材料强度的同时降低其生热。新型碳材料制备成本高,需要进一步探讨其放量制备的简易方法及分散工艺,以开发能够工业化生产的应用于负重轮的高强度和低生热NR基复合材料。     

超声波湿法混炼炭黑/天然橡胶复合材料的性能研究

利用超声波的乳化均质作用,将经水湿润的炭黑与稀释的天然胶乳混合均匀,然后采用蒸发成膜法和胶凝成膜法制备胶膜(炭黑/天然橡胶复合材料),探究制膜方法及超声波处理时间和功率对胶膜性能的影响。结果表明:蒸发成膜法成膜时间过长,打开的炭黑二次结构重新团聚,胶膜中炭黑分散性差,胶膜的拉伸强度较小,而胶凝成膜法稳定性更高,胶膜中炭黑分散性好;超声波处理时间为90 s、功率为840~960 W时,超声波的乳化均质效果最好,炭黑二次结构打开程度更高,此时采用胶凝成膜法制备胶膜,成膜速度快,炭黑来不及团聚,胶膜中炭黑分散性较好和结合橡胶较多,胶膜的拉伸强度较大。     

Rare earth compounds modified carbon black filled powdered natural rubber: Preparation,morphology and properties

Ten types of rare earth (RE) compounds modified carbon black (HAF‐RE) were prepared using chemical‐deposit method, then HAF‐RE were mixed with natural rubber latex to prepare HAF‐RE filled powdered natural rubber [P(NR/HAF‐RE)] by a carbon black/rubber latex coagulation method. It is found that most of the P(NR/HAF‐RE) vulcanizates showed better mechanical properties, especially higher tensile modulus, and tensile strength, compared with none‐rare earth modified carbon black filled powdered natural rubber [P(NR/HAF)]. Dysprosium (Dy) modified carbon black (HAF‐Dy) filled powdered natural rubber [P(NR/HAF‐Dy)] was chosen for intensive investigation because of its better comprehensive mechanical properties. It is found that the adding of Dy compounds could help to get smaller particles with narrower particle size distribution, and results from the SEM analysis show that carbon black has been dispersed in rubber matrix uniformly with diameter of 50–150 nm. The TEM analysis showed that Dy compounds could obviously reduce the aggregation of primary particles of carbon black, and promote the dispersion of carbon black in P(NR/HAF‐Dy) particles. © 2008 Wiley Periodicals, Inc. JAppl Polym Sci 2008     

纳米SiO_x补强天然乳胶膜抗剪切机理的研究

使用合适表面处理剂,通过剪切、搅拌混合和超声波处理,制备了高浓度n—SiOx分散悬浮液;在合适的剪切强度下,将分散悬乳液按n-SiOx质量分数为2.0%均匀分散在天然乳胶中,制备了n-SiOx补强型天然乳胶膜试样。乳胶膜直角撕裂强度测试结果和扫描电子显微镜图像分析表明,n-SiOx粒子较好地分散在天然乳胶中,能与乳胶分子链形成较为牢固的整体结构,其剪切强度较白炭黑试样提高了52.32%;n-SiOx悬浮液浓度是实验的主要影响因素,超声波分散时间、25G工作头转速和均质分散时间次之。     

Preparation and characterization of water‐swellable natural rubbers

Water‐swellable rubbers were prepared by dispersing the superabsorbent polymer particles, sodium polyacrylate particles, in natural rubber, and their water absorption properties were investigated. Sodium polyacrylate particles were synthesized using the inverse suspension polymerization technique, and their thermal and water absorption properties were characterized. The equilibrium water uptake in sodium polyacrylate particles was strongly dependent on both the salt concentration of aqueous media and crosslinking density of polymer. The dynamic and equilibrium water‐swelling behavior of the prepared rubbers were significantly affected by addition of carbon black, hydrophilic polymer, and coupling agent. Those effects were well explained by microphotographic morphologies obtained using a scanning electron microscope. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 115–121, 2001     

Preparation of carbon black/natural rubber latex masterbatch in bead form

Carbon black/natural rubber latex masterbatch in the form of spherical beads was prepared according to the acid-precipitation method. High-loading carbon black (40 phr) was incorporated in natural rubber with the aid of a nonionic surfactant (Nonidet P40). Shearing the beads in an internal mixer provided good integration of carbon black in the rubber matrix and hence the high bound rubber content. Results confirmed the contribution of chemical interaction to the bound rubber content. By an oxidation process, the size of modified carbon black was reduced, whereas the large agglomeration took place in the case of partially graphitized carbon black. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 489–498, 2001     

Chitin nanocrystals reticulated self-assembled architecture reinforces deproteinized natural rubber latex film

Natural rubber (NR) latex was initially deproteinized, then, the interactions between chitin nanocrystals (ChNCs) and deproteinized natural rubber (DNR) latex particles in an aqueous system and the properties of DNR/ChNCs composites were investigated. Composite films were obtained by casting and evaporating off the prevulcanized DNR/ChNCs complexation rather than simply mixing of DNR latex and ChNCs suspension. The results of DLS and TEM confirmed that this kind of complexation was formed between negative charged DNR and positively charged ChNCs by self-assembly. The tensile strength of composite films containing 4 wt% ChNCs was 25.00 ± 1.42 MPa, which was 3.11 multiples of the pure pre-vulcanized DNR. DNR/ChNCs composite films could provide excellent mechanical properties and avoid allergies caused by proteins in NR latex.     

Preparation and Properties of Natural Rubber/Palygorskite Composites by Co-Coagulating Rubber Latex and Clay Aqueous Suspension

Natural rubber (NR)/Palygorskite composites were prepared by co-coagulating rubber latex and clay aqueous suspension. Org-palygorskite was attained by using cetyltrimethylammonium bromide (CTAB) and the four factors influencing the average diameter of palygorskite were discussed. Four optimal conditions of preparing minimum average diameter were determined which included the concentration of palygorskite, the concentration of sodium polyacrylate, ultrasonic time and ultrasonic power. Mechanical properties suggested that composites using modified palygorskite which were dispersed by ultrasonic wave were the best, the tensile strength, tear strength, 300% modulus and shall hardness increased by 77.14%, 118.18%, 242.86% and 65.2%, respectively. Modified palygorskite was shown by FTIR spectrogram and observed by ESEM. Modified palygorskite dispersed by ultrasonic wave were dispersed into the rubble uniformly, some stick particles inserted into the rubber and it is difficult to find stick shape, and there were 20% particles belonging to nanomaterials and 80% micromaterials.