Study Of Low N-nitrosamine Accelerator On Properties Of Natural Rubber Latex And Natural Rubber Latex Film

At present, the ultra fast accelerator such as zinc diethyl dithiocarbamate(ZDC) and tetramethylthiuram disulfide(TMTD) were commonly used in latex industry. But these accelerator will be easy to produce carcinogenic N-nitrosamines during the curing process. But sterically hindered zinc diisobutyl dithiocarbamate(ZDiBC) and diisobutylthiuram disulfide(TiBTD) as the accelerator will be difficult to produce N-nitrosamines. But there was little research about the impact of ZDiBC or TiBTD on colloidal properties of latex, curing properties of latex and NR film, mechanical properties of vulcanized NR film. In this paper, using ZDiBC and TiBTD which produced lower N-nitrosamines and ZDC and TMTD which commonly used in latex industry as the accelerator of NR latex, the impact of the dosage of ZDiBC and TiBTD, curing temperature and storage time on colloidal properties of vulcanized latex, mechanical properties of vulcanized NR film were studied. The impact of the dosage of accelerator, curing temperature on cure rate of latex and curing properties of NR film were studied.The results showed that:The impact of the dosage of ZDiBC on viscosities, mechanical stability and thermal stability of mix latex were small. But the impact of the dosage of ZDiBC on viscosities and mechanical stability of were great, with ZDiBC amount increased, the viscosities significantly increased, the mechanical stability decreased. For ZDiBC system, the impact of the storage time on viscosities of vulcanized latex were great, with the storage time increased, the viscosities of vulcanized latex significantly increased. The impact of the dosage of TiBTD on viscosities, mechanical stability and thermal stability of mix latex and vulcanized latex were small, with TiBTD amount increased, the viscosities, the mechanical stability and thermal stability changed small.For TiBTD system, the impact of the storage time on viscosities of vulcanized latex were great, with the storage time increased, the viscosities of vulcanized latex significantly increased. The impact of the dosage of ZDC and TMTD on viscosities, mechanical stability and thermal stability of mix latex and vulcanized latex were small.The impact of the dosage of ZDiBC on cure rate of vulcanized latex were great, with ZDiBC amount increased, the cure rate speeded up. For ZDiBC system, the cure rate of latex faster than ZDC system. The impact of the dosage of ZDiBC on cure rate of mix latex film were great, with ZDiBC amount increased, the cure rate speeded up. For ZDiBC system, the cure rate of mix latex film increasing degree bigger than ZDC system. The impact of the dosage of TiBTD on cure rate of mix latex film were great, with TiBTD amount increased, the cure rate speeded up. For TiBTD system, the cure rate of NR latex film slower than TMTD system.With ZDiBC amount increased, the100%modulus,300%modulus, tensile strength of mix latex vulcanized film increased, tear strength, elongation at break of mix latex vulcanized film first increased and then decreased. For ZDiBC system, the100%modulus,300%modulus, tensile strength, tear strength of mix latex vulcanized film lower than ZDC system. With TiBTD amount increased, the100%modulus,300%modulus, tensile strength,tear strength of mix latex vulcanized film increased, elongation at break of mix latex vulcanized film decreased. For TiBTD system, the100%modulus,300%modulus, tensile strength, tear strength of mix latex vulcanized film lower than TMTD system.With ZDiBC amount increased, the100%modulus,300%modulus, of vulcanized latex film increased, tensile strength, tear strength, elongation at break of vulcanized latex film decreased. With the curing temperature increased, for ZDiBC system, the tensile strength, tear strength, elongation at break of vulcanized latex film decreased. With the vulcanized latex storage time increased, for ZDiBC system, the degree of cure increased, the tensile strength, tear strength, elongation at break of vulcanized latex film decreased.