The Effect Of Hanging Storage Of Coagulated Rubber Sheet On The Properties Of Natural Rubber

In recent years, tire production standardization, automation technology and high performance processing for tyre technology developing, the performance of NR for raw materials and quality are put forward higher requirements. In Malaysia, Research and provide "a garden fresh natural rubber latexâ†'natural microorganisms solidify a12months(6months)â†'dehydrationâ†'granulationâ†'dryingâ†'NR products production and improve the quality of NR. In China, standard (SCR) widely used "fresh latexâ†'ammonification savedâ†'acid coagulationâ†'coagulation sheets of washingâ†'dehydrationâ†'granulationâ†'drying. Compared With imported rubber (smoke piece of gum, RSS),the tensile properties and consistent performance are poor, plastic retention value (P0) and (PRI) are low, Vulcanization is slow and poor anti-aging performance, not be bullished on tire enterprises gradually. To take advantage of foreign resources and markets, the domestic companies build cooperation and factories in NR producer. Ken rubber in the process of going out and found that Indonesia take way of hanging film to improve the rubber PO, PRI. Guang ken found that Indonesia take way of hanging film to improve the rubber PO, PRI.To study the difference of coagulation process at home and abroad, and adopting the way of hanging coagulation sheets to improve the P0, PRI value of NR is practical.this topic use acetic acid and natural coagulate fresh latex. After coagulation, coagulation sheets go for different hanging storage time, and then observed the NR of physical and chemical properties, such as nitrogen, PO, PRI, Mooney viscosity and gel content and the crosslinking density. Adopt processing analyzer for analysis the processing properties of NR rubber;Using a thermogravimetric analyzer (TG-DTG) test samples with the thermal stability with hanging time. Finally analyzes the physical and mechanical properties and dynamic thermal mechanical properties change along with the hanging timeThe experimental results show that as the hanging time rising, the nitrogen content of NR reduces; P0of acetic acid coagulation samples rose with the increase of hanging time, to stable gradually after24days, and P0of natural coagulation samples had a certain degree of reduced before hanging18days, greater than18days began to increase, after24days increase amplitude slow; PRI values increase with hang time. In the process of hanging, physical crosslinking density and the gel content of NR increases, when the hanging time more than18days, growth slows.Rubber processing analyzer (RPA) scanning analysis, suspension time less than18days, molecular chains happen to chemical or physical crosslinking, make NR initial crosslinking structure more closely, have advangtage to production and processing. Suspension for more than18days, due to the influence of the external environment, molecular chain will occur to varying degrees of degradation, make processing performance becomes poor. Thermogravimetric curve analysis showed that the hanging time has a positive role to the thermal stability of NR.Heat oxygen degradation is mainly divided into two steps. Suspension for18days, the initial degradation temperature of acetic acid coagulation samples rose from339.7℃to343.2℃, the initial degradation temperature of natural solidification samples rose from329.4℃to332.1℃.Vulcanizates performance analysis show that with the hanging time rising, the mechanical properties increase,then reduce. When the suspension time18days, the strength is the most,but have no obvious change in samples. Mechanical strength of natural coagulation samples can keep around20mpa after aging, and acetic acid coagulation samples can also reach18mpa. Through analysis on the dynamic thermal mechanical scanning, loss factor response to temperature of vulcanizates NR had a trend to move to high temperature, shows that hanging has a certain amount to improve the aging resistance of NR.