我国健身器材用天然胶乳制品的发展概况

介绍我国健身器材用天然胶乳制品的发展概况。彩色天然胶乳管主要采用热敏挤出法和多次浸渍法生产,彩色天然胶乳片的生产工艺从传统浸渍法向连续浸渍法发展。我国健身用天然胶乳制品应通过开发和应用新材料和新技术来避免表面喷霜,研发环境友好的表面处理工艺替代有毒害的氯化处理工艺,并进一步提高天然胶乳制品的抗撕裂性能和拉伸性能。     

天然胶乳制品凝固剂浸渍法与凝固剂体系的应用和改进

综述天然胶乳制品凝固剂浸渍法和凝固剂体系及其配方,分析凝固剂浸渍法配套沥滤方法,介绍清凝固剂体系和陶土凝固剂体系在天然胶乳制品中的应用与改进。随着工艺和技术的进步,应用新材料对天然胶乳制品凝固剂体系的改进应有利于提高制品质量和生产效率,减少制品清洗对环境的污染;充分沥滤是确保天然胶乳凝固剂浸渍制品性能优良和天然胶乳医用制品使用安全的重要工艺措施。     

天然胶乳积层制品的脱层研究

对天然胶乳制品积层浸渍进行了研究，介绍影响积层浸渍的因素：胶模干燥程度、胶乳中的皂类、胶膜的湿润性、凝固剂，并对其规律进行研究．提出了减少积层失败的措施。     

低蛋白天然胶乳手套的生产工艺

低蛋白天然胶乳的蛋白质含量较低,能有效改善天然胶乳手套的致敏性。采用尿素与碱性蛋白酶协同作用去除胶乳中的部分蛋白质,并将低蛋白天然胶乳用于制备家用手套,研究了低蛋白天然胶乳硫化速度和稳定性的调控,以及手套浸渍成型工艺与产品性能。结果表明,低蛋白天然胶乳与普通高氨浓缩胶乳相比,稳定性更高,硫化速率较低;通过调整硫化配方,提高了硫化速率;手套浸渍成型工艺无明显区别,力学性能略有下降,为低蛋白天然胶乳制品的优化设计提供了参考。     

胶乳制品表面的氯化处理

在某些用途中,浸渍胶乳制品必需具有光滑的表面。例如家用橡胶手套应带脱方便。表面粘附虽能通过搽抹干粉(干滑石粉)来解决但这种粉末在实际使用时会脱落或洗掉,要使胶乳制品表面得到更加持久的光滑性可以将其放入溶解了游离卤素通常是氯)的液槽中浸渍亦即对制品表面进行卤化处理。     

胶乳级碳酸钙在天然胶乳薄膜制品中的应用研究

根据胶乳级专用碳酸钙的特性，通过实验探讨了在天然胶乳薄膜制品中的应用，研究了用量对产品性能的影响。结果表明，胶乳级碳酸钙可以部分用于天然胶乳薄膜制品的生产，不仅可大幅度地降低生产成本，还以提高胶乳制品的物理性能。     

《关于薄型外科用手套及医用检查手套进口》

1986年美国橡胶工业生产了14亿副薄型医用手套。1986年进口2.62亿副外科及医用检查手套,1987年进口6.38亿副手套。生产这类手套的主要原材料是天然胶乳。1987年美国消耗了7.2万吨天然胶乳,比1986年增加10%。预计1988年天然胶乳的消耗量将增加5～10%。将近50%的胶乳被用于生产浸渍制品。鉴于生产手套用的胶乳的缺点,美国《Godyear》公司     

天然胶乳手套与合成胶乳手套的发展

介绍天然胶乳手套的起源和发展以及天然胶乳检查手套、外科手套、织物浸渍防护手套、家用手套、工业手套的用途、规格、特点和表面形式,指出因天然胶乳手套存在安全性能和使用性能的不足,促进了合成胶乳手套和人造胶乳手套的发展。丁腈胶乳检查手套因技术进步和成本降低成为天然胶乳检查手套的主要竞争者;低蛋白无粉天然胶乳外科手套、氯丁胶乳外科手套和聚异戊二烯胶乳外科手套成为对天然胶乳过敏症医护人员的选择;在非医疗领域,合成胶乳手套和人造胶乳手套适用于特殊领域的防护需求。     

帘线浸渍用丁苯胶乳的合成研究

帘线浸渍用丁苯胶乳,随帘线材料的不同也在不断改进。目前国内以尼龙和人造丝帘线为主,帘线浸渍液使用R(间苯二酚)-F(缩甲醛)-L(胶乳)溶液(以下简称RFL溶液)。在国外,浸渍液中L项采用丁苯吡-丁苯混合胶乳,但丁苯吡胶乳的价格比丁苯胶乳高一倍。而国内迄今则仍是以进口丁苯吡胶乳和天然胶乳相混用,但天然胶乳质量波动大,且浸渍时泡沫大,易造成浸渍不完全,影响帘线和橡胶的粘接强度。据此,我们开展了帘线浸渍用丁苯胶乳的合成研究。     

沥滤对天然胶乳胶膜性能的影响

沥滤是天然胶乳浸渍制品一种非常有用且重要的工艺。沥滤可降低胶膜中可溶性物质的含量，改善胶膜的物理性能，降低胶膜中蛋白质含量和亚硝胺含量，从而提高制品的质量。     

生物凝胶法处理无粉检查手套的技术

采用生物凝胶法处理无粉橡胶检查手套，成型后的胶膜先浸三价金属离子盐溶液（４％硫酸铝溶液），再浸生物凝胶聚合物，最后用硅油进行外表面涂覆使手套无需经过水硫化、氯化等工序，制品表面滑爽。     

Effect of magnesium and phosphate ions on the stability of concentrated natural rubber latex and the properties of natural rubber latex–dipped products

The presence of Mg²⁺ ions was found to be a major cause of destabilization of natural rubber (NR) latex. On the other hand, the addition of excess PO ions to remove Mg²⁺ ions could adversely affect the physical properties of dipped products made of NR latex. A series of concentrated latex samples were treated with varying amounts of Mg²⁺ and PO ions. Changes with time in the characteristics of the treated latex samples such as mechanical stability time, volatile fatty acid number, and chemical stability time and in the physical properties of the dipped products such as aged and unaged tensile properties were monitored. The latex batch with a PO ion concentration of 30 ppm was found to produce the best‐quality latex and dipped products. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 99: 3120–3124, 2006     

Compounding of poly(dimethyl siloxane) to reduce tack in natural rubber

Tack in natural rubber latex was reduced by compounding poly(dimethyl siloxane) (PDMS) emulsion in concentrated latex. Sheet and dipped film surfaces were examined with Fourier transform infrared spectroscopy using attenuated total reflection (FTIR–ATR) and by contact angle measurements. Autohesive tack and tensile properties were also determined. For both sheet and dipped film, FTIR–ATR showed that the PDMS concentration was higher at the glass surface than at the air surface. The contact angle of ethylene glycol on the rubber decreased with increasing PDMS content. Autohesive tack for sheet and dipped film also decreased with increasing PDMS amount; however, annealing for 1 week at 70°C in air did cause tack to rise in the sheets. The rubber surface could be made nonadhesive by addition of sufficient PDMS. PDMS caused a decrease in tensile strength for the sheet, especially after annealing; however, PDMS did not cause a substantial decrease in percentage elongation for the sheets, except at relatively high PDMS contents. The tensile strength and percentage elongation for dipped film was not affected by PDMS over the much more limited PDMS concentration range studied. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 519–526, 2001     

Studies on rubber‐to‐nylon tire cord bonding

Nylon tire cord (1680/2) was dipped in different adhesives based on resorcinol formaldehyde resin and latex (RFL) and was bonded to natural rubber‐based compounds. The resin‐rubber ratio in the RFL adhesive was optimized. The variation of pull‐through load was studied by varying the drying and curing temperature of the dipped nylon tire cord. RFL adhesive based on vinylpyridine latex was found to have better rubber‐to‐nylon tire cord bonding, compared with the one based on natural rubber latex. Addition of a formaldehyde donor into the RFL adhesive/rubber compound improves adhesion. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1197–1202, 1999     

The Role of Coagulants on the Preparation of Dipped film from Radiation Vulcanized Natural Rubber Latex

The effect of coagulants on the preparation of dipped film with good physical properties was studied. In order to optimize various parameters like coagulant concentration, latex concentration, and former dipping time in latex and coagulant, the effect of coagulant on the physical properties of radiation vulcanized natural rubber latex film was evaluated. Calcium nitrate, calcium chloride, and ammonium nitrate were used as the coagulant by dissolving either in water or ethanol. Calcium nitrate solution was found to be the best one among the coagulants used.     

Effects of ozone and UV on tire cord adhesion

Ozone exposure of resorcinol-formaldehyde-latex (RFL) dipped tire cords reduces adhesion because ozone attacks the double bonds in the butadiene component of the rubber latex in RFL and impairs its cocuring with the solid rubber compound. This mechanism also explains: (a) the ineffectiveness of chemical antiozonants or chloroprene latex as RFL additives, (b) the increased ozone sensitivity of RFL adhesion with progressive curing of RFL dip, and (c) the insensitivity to ozone of adhesion with RF-EPDM adhesives. A major reduction in the rate of adhesion loss in either ozone (50 pphm, 50% RH) or UV (carbon arc, 4 hr) was demonstrated when small amounts of waxes (3% solids basis) were added to the RFL dip. The waxes protect the RFL adhesive by blooming to the surface of the adhesive treated cord.     

耐热EPDM汽车多楔带产品的研制

以三元乙丙橡胶（EPDM）为主胶品种,骨架材料选用EPDM浸胶处理的高模量低收缩聚酯线绳,表面织物选用涤棉布,在压缩层胶料配合中加入预处理短纤维,研制出一种新型耐热EPDM汽车多楔带产品。所研制的EPDM多楔带采用四轮疲劳试验机进行动态疲劳寿命测试,运行450h停止试验,检查皮带完好,未出现任何裂纹、掉楔、起球和断裂等失效现象,并且聚酯线绳界面粘合良好,完全满足现代汽车对传动带的要求。     

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。     

Improvement of the mechanical and thermal properties of silica‐filled polychloroprene vulcanizates prepared from latex system

In this work, well‐dispersed silica suspension having excellent storage stability was prepared by using an ultrasonic probe. The obtained silica suspension and curatives were added into the polychloroprene (CR) latex for preparing silica‐filled CR latex compounds having various silica loadings. Then, the silica‐filled CR vulcanizates were prepared via a dipping process. The thermal and mechanical properties of the dipped CR vulcanizates containing silica dispersed by using an ultrasonic probe were compared with those of the dipped CR vulcanizates containing silica dispersed by using a mechanical stirrer. By using thermogravimetric analysis, it could be seen that thermal resistance of the dipped CR films having silica prepared by ultrasonic probe is greater than that prepared by using the mechanical stirrer. This result corresponds well with their tensile strength after aging in the hot‐air oven. In addition, modulus, tensile strength, and tear strength of the vulcanizates prepared from CR latex compounds containing silica prepared by using the ultrasonic probe are obviously greater than those prepared by using the mechanical stirrer, especially at high silica loading. This is because the silica prepared using the ultrasonic probe is uniformly distributed and dispersed throughout the CR matrix, as can be observed in the scanning electron microscope micrographs. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012