天然胶乳的电子束辐照硫化

使用低能量电子加速器电子束有利于降低天然胶乳的辐照硫化成本,但存在射线穿透力低的缺点,而采用转鼓方式,其电子束能量利用率要高于容器型辐照方式,且具有实用价值。     

辐射硫化低蛋白天然胶乳的研究

采用正交试验设计对低蛋白天然胶乳进行辐射硫化,研究了辐射硫化低蛋白天然胶乳的物理性能,探讨了辐射后胶膜加热时间对胶膜性能的影响。结果表明：低蛋白天然胶乳辐射硫化后的物理性能都达到生产指标,胶膜加热时间对胶模的拉伸强度和拉断永久变形有明显的影响。     

填料对预硫化天然胶乳胶膜性能的影响

把２０份的沉淀法白炭黑、陶土及重质碳酸钙加到配合胶乳中搅拌混合,在７０℃条件下预硫化２小时。采用浇注的方法准备试片。测定了水沥滤对胶膜机能产生的影响,同时对橡胶与填料的相互作用、耐老化、应力松弛及沥滤后胶膜的结构进行了研究。由于加了沉淀法白炭黑、陶土及重质碳酸钙,降低了拉伸强度及扯断伸长率,但增加了预硫化胶乳胶膜的定伸应力;沥滤增进了胶膜性能。加入沉淀白炭黑及陶土改进了胶膜的抗裂强度;沉淀法白炭黑     

氮化硼对天然胶乳硫化胶膜力学性能的影响

研究氮化硼用量、不同改性氮化硼对天然胶乳胶膜力学性能的影响,通过热重分析仪分析其热稳定性.结果 表明:随着氮化硼用量的增加,复合胶乳胶膜的力学性能先增加后降低,当氮化硼的用量为20份,天然胶乳胶膜的力学性能最好;使用KH570改性过的氮化硼制得天然胶乳胶膜的性能好,且KH570的最佳用量为2.5份时,复合胶膜的力学性能...     

浅析天然胶乳预硫化工艺

为了延长胶粘剂的保存期，本文介绍天然胶乳制备胶粘剂的预硫化工艺。     

天然胶乳橡胶手套硫化问题的探讨

<正>一、引言胶乳硫化能充分改变或改善胶乳胶料性能,通常在胶乳配料时提高温度的情况下进行,硫化后的胶乳称为预硫化胶乳。胶乳硫化一般只适用于天然胶乳,是部分或完     

交联助剂对过氧化物硫化天然胶乳性能的影响

选用不同的过氧化物硫化体系制得硫化天然胶,在此基础上探讨了不同种类及用量的交联助剂和热处理温度对硫化效果的影响.结果表明:选用BPO过氧化物硫化天然胶时,添加3份DVB交联助剂的硫化天然胶,基本达到了硫黄硫化的基本力学性能;选用过氧化二叔丁基-硫酸亚铁络合物的氧化还原体系,添加3份的SJ-1交联助剂,在80℃以上时,可使硫化天然胶性能进一步提高,拉伸强度相比BPO过氧化物硫化的天然胶增加了近一倍.平衡溶胀试验的结果表明,氧化还原体系制得的硫化胶有最小的平衡溶胀增量和最大的凝胶含量.     

过氧化物预硫化天然胶乳胶膜的热氧稳定性研究

用热重法－微商热重法（TG－DTG）和差热分析（DTA）研究了不同交联程度和不同硫化工艺条件和过氧化物硫化胶乳（PPVL）胶膜的热氧稳定性。结果表明，PPVL胶膜的热氧稳定性与交联程度有关。交联程度较低（溶胶指数较高）时，起始降解温度较高；交联程度较高（溶胀指数较低）时，起始降解温度较低。不同硫化工艺对PPVL胶膜的热氧稳定性有一定影响，起始降解温度和DTG峰温度与起始放热温度和第一放热峰温度之间有呈反比的趋势。     

无氨天然胶乳性能研究

研究采用超速促进剂PX/硫黄/氧化锌硫化体系的无氨天然胶乳贮存性能、工艺性能、胶膜拉伸性能及自硫化机理。结果表明:无氨天然胶乳用异噻唑啉酮类衍生物保存剂对促进剂PX/硫黄/氧化锌硫化体系具有硫化协同效应;异噻唑啉酮类衍生物会使无氨配合胶乳在室温贮存时产生自硫化;适当调整促进剂PX/硫黄/氧化锌用量,可得到贮存性能、成膜性能和胶膜拉伸性能较好的无氨配合胶乳。     

菠萝叶纤维/天然胶乳复合海绵的制备及吸附性能研究

将菠萝叶纤维(PALF)添加于天然胶乳(NRL)中,采用Dunlop工艺制备复合海绵,研究了PALF添加量对复合海绵的力学性能、回弹性、压缩永久变形值和吸附甲醛、氨性能的影响。结果表明,与纯天然胶乳海绵相比,复合海绵具有更加优异的吸附性能,且随着添加量的增加和吸附时间的延长,吸附量呈增大趋势;而其力学性能、回弹率降低,压缩永久变形升高,符合HG/T 4666—2014标准。PALF的加入可以提高NRL吸附性能,而对复合海绵其他物理性能影响较小,能够满足其在相应领域的应用需求。     

菠萝叶纤维/天然胶乳复合海绵的制备及吸附性能研究

将菠萝叶纤维(PALF)添加于天然胶乳(NRL)中,采用Dunlop工艺制备复合海绵,研究了PALF添加量对复合海绵的力学性能、回弹性、压缩永久变形值和吸附甲醛、氨性能的影响。结果表明,与纯天然胶乳海绵相比,复合海绵具有更加优异的吸附性能,且随着添加量的增加和吸附时间的延长,吸附量呈增大趋势;而其力学性能、回弹率降低,压缩永久变形升高,符合HG/T 4666—2014标准。PALF的加入可以提高NRL吸附性能,而对复合海绵其他物理性能影响较小,能够满足其在相应领域的应用需求。     

Studies on the curing behaviour and mechanical properties of styrene/methyl methacrylate grafted deproteinized natural rubber latex

The graft copolymerization of styrene/methyl methacrylate (MMA) onto deproteinized natural rubber (DPNR) latex was carried out using ammonium peroxy disulfate (N₂H₈O₈S₂) as the initiator. The presence of the grafted polystyrene (PS) and polymethyl methacrylate (PMMA) on the rubber backbone was confirmed by FTIR spectroscopy. The effects of monomer concentrations on curing characteristics and mechanical properties were studied. It was found that the cure time and scorch time were increased with increasing monomer concentration whereas the torque_max–min value was slightly decreased. It was also noted that the increase in the monomer concentration resulted in stiffer rubber with increased modulus and reduced elongation at break.     

天然胶乳的氢化

以水合肼、双氧水和硼酸为催化体系,对天然胶乳进行非贵金属催化的原位母体加氢.并用核磁共振氢谱对氢化天然胶乳的结构进行表征.结果表明,氢化度随着硼酸用量的增加而增大,当硼酸/碳碳双键(摩尔比)达到0.25时,天然胶乳的加氢度接近60%;     

Adsorption behaviour of carbon black/latex by cationised cotton fabrics

A carbon black/latex dispersion was prepared by mini‐emulsion polymerisation, and its absorption behaviour towards cationised cotton fabric was investigated. The results indicated that the prepared carbon black/latex dispersion had excellent freeze–thaw stability. Cotton fabric that was cationised with 3 g/l of 3‐chloro‐2‐hydroxypropyltrimethyl ammonium chloride at a liquor ratio of 30:1 can be optimally dyed with 4% owf carbon black/latex under the conditions of pH 7.2, 60 °C, and 1 h. The adsorption behaviour of the carbon black/latex towards cationised cotton fabric followed the Langmuir adsorption isotherm, with a lower dyeing rate and a better colour levelness than the ordinary carbon black dispersion with binder.     

砖红壤/天然胶乳复合胶膜的制备与性能研究

研究了砖红壤对天然胶乳的补强作用。将砖红壤原土中的细粒子制成悬浮液,加入预硫化天然胶乳中,制备砖红壤/天然胶乳复合胶膜,并分析胶膜的结构特性、力学性能和交联密度等。结果表明,砖红壤粒子在橡胶相中分散均匀,砖红壤细粒子对天然胶乳具有优异的补强效果,硫化胶膜的拉伸强度和撕裂强度均有大幅度的提高,这是由于砖红壤的加入能够促进橡胶的硫化,砖红壤中的氧化铁能够与橡胶分子链中的不饱和双键结合,提高了砖红壤在橡胶相中的分散性,使二者形成良好的界面结合。     

蛋白质含量低的天然胶乳制品

讲述了无粉天然胶乳制品的生产方法及用其制造的无粉天然胶乳手套。该手套的可抽出蛋白质含量非常低,无需经卤化处理。这种方法是：在将天然胶乳制品从模型上剥离下来的前后,采用漂洗溶液处理。由于漂洗溶液含有离子形式的离解金属盐,可降低胶乳中的蛋白质含量。当制品从模型上剥离下来后,漂洗溶液也可除掉制品上的残留粉末,生产出无粉末的天然胶乳制品。无氯处理的制品具有良好的抓着性能,并且贮存期也比同类经氯化处理的制品要高。     

Diimide hydrogenation of natural rubber latex

Hydrogenation is one important method of chemical modification, which improves the physical, chemical and thermal properties of diene‐based elastomers. Natural rubber latex (NRL) could be hydrogenated to a strictly alternating ethylene‐propylene copolymer using a diimide reduction system. The diimide reduction technique of NRL was accomplished by using hydrazine hydrate/hydrogen peroxide and Cu²⁺ as catalyst. The hydrogenated products are characterized by FTIR and NMR spectroscopy. It has been found that cupric acetate is a highly active catalyst for the reaction and the addition of a controlled amount of gelatin demonstrated a beneficial effect on the degree of hydrogenation, whereas, sodium dodecyl sulfate (SDS) acted as a stabilizer of the latex particle in the reaction system and reduced the degree of hydrogenation. In the presence of SDS, a longer reaction time and a higher amount of hydrazine hydrate was required for hydrogenation of NRL. Gel formation during hydrogenation does not significantly affect the degree of hydrogenation. Gel inhibitors such as hydroquinone also decrease the degree of hydrogenation. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Noncatalytic hydrogenation of natural rubber latex

Hydrogenation is an important method of chemical modification, which improves the physical, chemical, and thermal properties of diene‐based elastomers. Natural rubber latex (NRL) could be hydrogenated to a strictly alternating ethylene–propylene copolymer using diimide generated in an in situ system. The diimide generated using the in situ technique for hydrogenation of NRL was accomplished by thermolysis of p‐toluenesulfonyl hydrazide (TSH). A molar ratio of TSH to double bonds equal to 2 : 1 was found to be the optimum ratio to provide a high percentage of hydrogenation. 95% Degree of saturation of NRL was achieved in o‐xylene. Hydrogenated products are characterized by FTIR and NMR spectroscopy. The thermal stability of hydrogenated rubber was improved as shown from the results of thermogravimetric analysis. From the differential scanning calorimetry measurement, the glass transition temperature of the hydrogenated product did not appear to change. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2885–2895, 2007