| Natural rubber latex (NRL) is possessed with excellent synthesis performance, which has been widely used in medical and industrial fields, etc. Natural rubber vulcanization agent additives would be added in the process of dairy production in order to meet the requirement of product performance, however, the secondary amine vulcanization accelerator would be used by most of the latex industry in natural rubber processing, which is prone to producing carcinogenic N-nitrosamines, and that could exert an evil influence on human health. Nowadays, the impact of N-nitrosamines in latex products on human health is one of the biggest problems that dairy products has been faced, at the same time, reducing the content of N-nitrosamines in rubber processing industry must address the technical issues. Some measures have been taken to reduce the levels of N-nitrosamines in a number of foreign products, but the problem has not been solved yet.ZBEC and TBzTD are Environmental and low N-nitrosamines vulcanization accelerators, which can replace the traditional accelerators to reduce N-nitrosamines. In addition, Mg (OH)2and other alkaline earth metal hydroxides can be used as to adjust the content of1N-nitrosamine to inhibit the formation of N-nitrosamines in latex products. In the present work, the effect of ZDC、ZBEC、TETD、TBzTD and TBzTD-ZDC in sulfur curing system on colloidal properties of the compound, curing properties, N-nitrosamine content and mechanical properties have been investigated in this project. At the same time,.The effect of the type and content of nitrosamine inhibitor on colloidal properties of the compound, curing properties, N-nitrosamine content and mechanical properties have been investigated. Therefore, we can grasp the main factors of the impact on N-nitrosamine content in order to establish a new method of the reduction N-nitrosamines with independent intellectual property rights, and to provide a theoretical guidance, for the preparation of low-N-nitrosamine latex products in China.The results showed that: the content of N-nitrosamine of Sulfide film of natural rubber latex prepared by ZBEC accelerator was lower than that of ZDC, thus ZBEC is a non-polluting, environmentally friendly accelerator; As the curing temperature increased, the content of N-nitrosamines in the natural latex vulcanized film decreased; A small amount of Mg (OH)2, Ca (OH)2, Ba(OH)2can be used as an effective inhibitor of N-nitrosamines.The results showed that: There was little difference on the effect of ZDC and ZBEC on viscosities, which changed fractionally with the elongation of storage time in the tie latex prepared by ZDC accelerator and tie latex prepared by ZBEC accelerator. However, the difference between the effect of TETD and TBzTD on viscosities was large. The viscosity of tie latex prepared by TETD accelerator changed slightly in the first there days and increased lightly in the last days. However, the viscosity of tie latex prepared by TETD accelerator increased rapidly with the elongation of storage time. The viscosities increases rapidly with the elongation of storage time in the TBzTD and The viscosity of tie latex prepared by TBzTD-ZDC accelerator, and thickening phenomenon happened in these promote system.The results showed that: the effect of ZDC and ZBEC on mechanical properties of sulfide film was obvious, with the increase in the amount of ZDC(0.5-1.5phr), the100%modulus,300%modulus, tensile strength and tear strength increased, while of ZBEC increased first(0.5-1.0phr) and then decreased(1.0-1.5phr); However, the effect of TETD and TBzTD on mechanical properties of Sulfide film was slender, with the increase in the amount of TETD and TBzTD form0.5phr to1.5ph the100%modulus,300%modulus, tensile strength and tear strength increased first and then decreased. When the proportion of TBzTD and ZDC was certain, the100%modulus,300%modulus, tensile strength and tear strength of the vulcanized film were first increases and then decreases With the increase in the amount of TBzTD-ZDC form0.5phr to1.5phr in the TBzTD-ZDC sulfur curing system; the mechanical properties of the sulfide film are first increases and then decreases with the promotion of TBzTD increasing from0to1.0. When the amount of accelerant was certain, the100%modulus,300%modulus, tensile strength and tear strength of sulfide film prepared by ZDC and ZBEC accelerators was lager than that of sulfide film prepared by TETD and TBzTD.The results showed that: The results showed that: with the curing temperature increased, the mechanical properties of both ZDC promote system and ZBEC promote system increased first increased and then decreased. The100%tensile stress,300%modulus, tensile strength and tear strength reached the maximum the ZDC promote system under100℃, while these mechanical properties reached the maximum in the ZBEC promote system under110℃. Cure kinetics experiments showed that, as the curing temperature increased, the slope of ZBEC promote system was faster than that of ZDC promote system, that was to say, the reaction rate of ZBEC promote system was faster than that of ZDC promote system; From the curing reaction activation energy, the energy required of ZBEC promote system was higher than that of ZDC promote system, which indicated that ZBEC was easier to react in sulfur curing system. The crosslink density of vulcanized latex film is slightly lower than the latex curing film when the formulation was certain. The modulus, tensile strength and tear strength, showed a gradually increasing trend in the NR latex film vulcanized with with the extension of the leaching time. Therefore, leaching could can improve the film performance and improve product quality. A small amount of alkaline earth metal hydroxides, in particular, calcium hydroxide, can significantly play a role in curing properties and mechanical properties of cured film; With the increase in the amount of alkaline earth metal hydroxides, the t9o of vulcanized latex film would be extended, and the modulus, tensile strength and tear strength first increased and then decreased. |
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