三氯溴甲烷改性天然胶乳的力学性能与阻燃性分析

对单用三氯溴甲烷改性天然胶乳和并用三氧化二锑改性胶乳的硫化胶膜的力学性能和阻燃性能进行了研究,并采用TG和DTG进行了热性能的分析。结果表明:三氯溴甲烷与三氧化二锑改性天然胶乳比单用三氯溴甲烷改性胶乳的阻燃性要好;三氯溴甲烷用量增加,改性天然胶乳硫化胶膜的阻燃性提高,而力学性能下降;三氯溴甲烷改性胶乳的起始热降解温度提前,改性胶乳热降解为二步反应。     

不同改性方法对天然胶乳的性能影响

分别采用氯化石蜡与Sb2O3共混改性天然胶乳、用三氯溴甲烷卤化加成改性天然胶乳、以3-溴丙烯接枝共聚改性天然胶乳,对3种不同工艺所制备的改性天然胶乳与未改性天然胶乳进行了胶体性能、阻燃性及耐溶剂性能的比较。研究结果表明：3种改性胶乳的粘度比未改性天然胶乳的要高,且接枝改性胶乳和卤化改性胶乳变化较大,共混改性胶乳的变化较少;3种改性胶乳的阻燃性能高于未改性天然胶乳的;卤化改性天然胶乳和接枝改性天然胶乳的耐溶剂性较好,而共混改性天然胶的耐溶剂性较差。     

改性纳米粘土/天然胶乳复合材料的制备与性能研究

研究表面改性剂对纳米粘土/天然胶乳复合材料性能的影响。结果表明:烷基表面活性剂对纳米粘土改性后,天然胶乳硫化胶膜老化前后的拉伸强度均明显提高,十六烷基三甲基溴化铵(CTAB)的改性效果最好,当改性纳米粘土用量为2份时,天然胶乳硫化胶膜的拉伸强度最高;CTAB改性纳米粘土能提高天然配合胶乳的保存稳定性、粘度和机械稳定性,并提高天然胶乳硫化胶膜的物理性能和耐热老化性能,补强效果明显。     

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最好,热失重分析可知,改性的硫化胶膜的热稳定性有所提高。     

不同硫化体系天然胶乳胶膜的热氧降解过程及差异

用热重法微商热重法（ Ｔ Ｇ Ｄ Ｔ Ｇ） 和差热分析（ Ｄ Ｔ Ａ） 研究了不同硫化体系天然胶乳胶膜的热氧降解过程。试验结果表明,胶乳胶膜的降解反应均分三步进行,但降解过程存在较大差异,过氧化物预硫化胶乳胶膜的热氧降解最为彻底,而硫黄／ 促进剂 Ｔ Ｍ Ｔ Ｄ／ 氧化锌体系硫化胶乳胶膜的热氧稳定性最好。     

改性纳米碳酸钙对天然胶乳胶膜热性能的影响

探讨改性纳米碳酸钙对天然胶乳胶膜耐热老化性能和热降解性能的影响。结果表明，加入改性纳米碳酸钙可以改善天然胶乳胶膜的耐热老化性能和热降解性能；改性纳米碳酸钙用量为3份的天然胶乳胶膜耐热老化性能和热降解性能与防老剂264用量为1份的天然胶乳胶膜相当，而生产成本较低。     

不同硫化体系天然胶乳胶膜的热氧降解过程及差异

用热重法，微商法重法和差热分析研究了不同硫化体系天胶乳胶膜的热氧降解过程。试验结果表明，胶乳胶膜的降解反应均分三步进行，但降解过程存在较大差异，过氧化物预硫化胶乳胶膜的热氧降解最为彻底，而硫黄／促进剂ＴＭＴＤ＝氧化锌体系硫化胶乳胶膜的热氧稳定性最好。     

BCT-2无氨保存剂对浓缩天然胶乳保存效果及其性能的影响

研究了水溶性杀菌剂BCT-2保存浓缩天然胶乳的效果及对预硫化胶乳粘度、成膜特性、硫化胶膜干燥特性及力学性能的影响。结果表明,浓缩天然胶乳保存6个月以上的挥发性脂肪酸值最高为0. 048,要比GB/T 8289—2016的0. 06低,粘度和p H值也都符合应用的要求。预硫化胶乳的粘度在放置前6 d没有太大变化,不影响预硫化胶乳的基本性能,且成膜性能好;与传统高氨保存的硫化胶膜相比,BCT-2保存的硫化胶膜干燥时间短,干燥速率常数提高了5～6倍; BCT-2保存的硫化胶膜的拉伸强度变化不大,而撕裂强度为49. 31 k N/m。     

BCT-2无氨保存剂对浓缩天然胶乳保存效果及其性能的影响

研究了水溶性杀菌剂BCT-2保存浓缩天然胶乳的效果及对预硫化胶乳粘度、成膜特性、硫化胶膜干燥特性及力学性能的影响。结果表明,浓缩天然胶乳保存6个月以上的挥发性脂肪酸值最高为0. 048,要比GB/T 8289—2016的0. 06低,粘度和p H值也都符合应用的要求。预硫化胶乳的粘度在放置前6 d没有太大变化,不影响预硫化胶乳的基本性能,且成膜性能好;与传统高氨保存的硫化胶膜相比,BCT-2保存的硫化胶膜干燥时间短,干燥速率常数提高了5～6倍; BCT-2保存的硫化胶膜的拉伸强度变化不大,而撕裂强度为49. 31 k N/m。     

三氯溴甲烷改性天然胶乳的研究

用三氯溴甲烷改性天然胶乳，研究了反应时间、反应温度、三氯溴甲烷的用量等对改性胶乳的硫化胶膜物理机械性能的影响，利用DSC对产物进行了分析。结果表明，反应时间为10h，反应温度在35℃时，所得胶膜物理机械性能较好；随着三氯溴甲烷用量的增加，改性天然胶乳的硫化胶膜物理机械性能下降：三氯溴甲烷改性天然胶乳的玻璃化温度高于未改性天然胶乳。     

Novel nonammonia preservative for concentrated natural rubber latex

A derivative of sym‐triazine (HTT) was chosen as a new nonammonia preservative for concentrated natural rubber latex (CNRL) in place of NH₃–TT/zinc oxide (ZnO). The preservation effects of the HTT for CNRL, drying characteristics, mechanical properties, and cytotoxicity of the vulcanized natural rubber (NR) film were investigated. The results show that the CNRL was preserved steadily for more than 6 months with 0.3% HTT, and the volatile fatty acid number, viscosity, and mechanical stability of CNRL all met the requirements of ISO 2004:2010(E). The drying characteristics of the vulcanized NR film preserved by HTT retained no change compared with those of the film preserved by NH₃–TT/ZnO. The tensile strength and elongation at break of the vulcanized NR film preserved by HTT were 32.17 MPa and 853.80%, respectively; these were very similar to those of the film preserved by NH₃–TT/ZnO, whereas the tear strength reached 68.43 kN/m, and this was much higher than that by NH₃–TT/ZnO. The results of the cytotoxicity and dermal irritation tests prove that HTT is not especially harmful to humans. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41749.     

硫化NR胶乳胶膜的结构与性能研究

对不同硫化体系和硫化方式硫化的ＮＲ胶乳胶膜的结构与性能进行研究。结果表明：采用不同硫化体系的硫化胶乳所形成的硫交联键主要的为多硫键,硫化胶乳胶膜的结构对性能的影响因硫化方式不同而有差异。     

常用阻燃剂对氯化橡胶涂料阻燃性的比较

用作者设计的涂料阻燃试验方法结合热重分析法，研究比较了氯化石蜡、三氧化二锑、氧化锌、氧化铁红和二氧化锡等阻燃剂对氯化橡胶涂料的阻燃效果。结果表明，在氯化橡胶涂料体系中，用少量氧化铁红代替部分三氧化二锑，漆膜阻燃性不下降；氯含量５２％的氯化石蜡，其阻燃性高于氯含量７０％的氯化石蜡。     

无氨保存胶清及胶清胶性能的研究

采用水溶性、不挥发性的广谱抗菌剂——三嗪衍生物(HY)作为鲜胶乳的新型无氨保存剂,研究了HY对胶清凝固总用酸量、胶清胶及胶清胶硫化胶片性能的影响。结果表明,HY保存胶清凝固总用酸量大大减少,除氮含量略微超标外,胶清胶的各项指标均达到1级胶清胶的标准,胶清胶的塑性保持率(PRI)明显提高。HY胶清胶硫化胶片的拉伸强度和耐热氧老化能力均优于氨胶清胶硫化胶片。热解重量分析(TGA)结果表明,HY和氨胶清胶硫化胶片热氧降解均为2步反应,耐热氧降解能力基本相同。     

Preparation and characterization of organoclay‐rubber nanocomposites via a new route with skim natural rubber latex

Skim natural rubber latex (SNRL) is a protein rich by‐product obtained during the centrifugal concentration of natural rubber (NR) latex. A new method to recover rubber hydrocarbon and to obtain nanocomposites with organoclay (OC) was investigated. The approach involved treatment of SNRL with alkali and surfactant, leading to creaming of skim latex and removal of clear aqueous phase before addition of OC dispersion. Clay mixed latex was then coagulated to a consolidated mass by formic acid, followed by drying and vulcanization like a conventional rubber vulcanizate. X‐ray diffraction (XRD) studies revealed that NR nanocomposites exhibited a highly intercalated structure up to a loading of 15 phr (parts per hundred rubber) of OC. Transmission electron microscopy studies showed a highly exfoliated and intercalated structure for the NR nanocomposites at loadings of 3–5 phr organically modified montmorillonite (OMMT). The presence of clay resulted in a faster onset of cure and higher rheometric torque. The rubber recovered from skim latex had a high gum strength, and a low amount of OC (5 phr) improved the modulus and tensile strength of NR. The high tensile strength was supported by the tensile fractography from scanning electron microscopy. Thermal ageing at 70°C for 6 days resulted in an improvement in the modulus of the samples; the effect was greater for unfilled NR vulcanizate. The maximum degradation temperature was found to be independent of the presence and concentration of OC. The increased restriction to swelling with the loading of OC suggested a higher level of crosslinking and reinforcement in its presence. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3277–3285, 2006     

硫黄用量对天然胶乳膜性能的影响

采用凝固剂浸渍法制备天然胶乳硫化胶膜,并对其结构和性能进行研究。结果表明：天然胶乳预硫化程度随硫黄用量的增加而增大;胶膜硫化后的交联程度随硫黄用量的增加先增大后减小,在硫黄用量为1.25份时达到最大值;拉伸强度随硫黄用量的增加先增大后减小,在硫黄用量为1份时达到最大值,而拉断伸长率呈下降趋势;当硫黄用量为1份时达到最佳致密性。     

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.     

表面改性碳纳米管/天然橡胶复合材料的制备及性能研究

采用多巴胺对多壁碳纳米管(MWCNTs)进行非共价改性,得到多巴胺改性MWCNTs(简称PCNT)。将PCNT作为填料加入天然胶乳中制备PCNT/天然橡胶(NR)复合材料,并研究其性能。透射电子显微镜(TEM)分析结果表明MWCNTs经过多巴胺改性后在水中的分散效果明显改善。PCNT/NR复合材料的拉伸强度和撕裂强度明显提高,拉伸强度由22.7 MPa升至28.4 MPa,撕裂强度由26 kN·m^-1升至40 kN·m^-1。多巴胺用量适当的PCNT在NR基体中分散更均匀,填料与橡胶的相互作用较强,能够形成较好的填料网络结构,PCNT/NR复合材料的表面电阻显著降低。