不同保存体系低氨浓缩天然胶乳的性能研究

Study on Properties of Low Ammonia Concentrated Natural Rubber Latex with Different Preservation Systems

低氨浓缩天然胶乳能在一定程度上缓解高氨胶乳带来的氨污染问题,并在多种乳胶制品中获得越来越广泛的应用。本研究采用BCT-2、HY、HM和LS 4种天然胶乳保存剂与氨复合保存制备低氨浓缩胶乳,并与高氨浓缩胶乳进行对比分析,研究不同保存体系低氨浓缩胶乳性能之间的差异。结果表明,4种保存体系对低氨浓缩胶乳保存效果良好,均能达到GB/T 8289—2016国家标准的要求。其中,BCT-2保存的低氨浓缩胶乳挥发脂肪酸值(VFA No.)最低,但胶乳黏度值最高,机械稳定度(MST)最低,稳定性最差;此外,橡胶粒子平均粒径较高;热稳定性和氧化锌机械稳定性(ZST)较低;干胶膜强度较高。HY保存的低氨浓缩胶乳VFA No.较低,黏度最低,MST和热稳定度最高;浓缩胶乳预硫化速度最快;预硫化胶乳黏度最低,MST和热稳定度最高;硫化胶膜强度较高。HM保存的低氨浓缩胶乳黏度较低;MST较高,稳定性良好;浓缩胶乳干胶膜强度最低;浓缩胶乳预硫化速度最慢。LS保存的低氨浓缩胶乳VFA No.较高,黏度值较高;MST较低,稳定性较差;橡胶粒子粒径最小;浓缩胶乳干胶膜和硫化胶膜强度均最高;干胶膜热稳定性最好。对比分析表明,HY和LS保存低氨浓缩胶乳综合性能较好,其中HY低氨浓缩胶乳适于生产发泡制品、胶黏剂等,而LS低氨浓缩胶乳适于生产手套、气球等纯胶浸渍制品。

Low-ammonia concentrated natural rubber latex(CNRL)can alleviate the ammonia contamination problem caused by high-ammonia CNRL to a certain extent,and is gaining wider and wider application in a variety of CNRL products.In this study,four CNRL preservatives,BCT-2,HY,HM and LS,were used to prepare low ammonia CNRL,and the differences between the performances of low ammonia CNRL in different preserved systems were investigated by comparison with high ammonia CNRL.The results showed that the four preservation systems had good effect on the preservation of low ammonia CNRL,and all of them could meet the requirements of GB/T 8289—2016 national stan-dard.Among them,the low ammonia CNRL preserved by BCT-2 had the lowest volatile fatty acid value(VFA No.),but the viscosity value was the highest,the lowest mechanical stability(MST);in addition,the average particle size of rubber particles was higher;the thermal stability and zinc oxide mechanical stability(ZST)were lower;the dry rubber film strength was higher.The low ammonia CNRL preserved by HY had the lowest VFA No.,the lowest viscosity,highest MST and thermal stability;the fastest pre-cure speed;pre-cure latex with the lowest viscosity,highest MST and thermal stability;higher strength of vulcanized rubber film.HM preserved low ammonia CNRL with lower viscosity;higher MST and good stability;the lowest dry rubber film strength;the slowest pre-cure speed.LS preserved low ammonia CNRL with higher VFA No.and higher viscosity value;lower MST and poor stability;the smallest rubber particle size;the highest concentrated latex dry rubber film and vulcanized rubber film strength;the best dry rubber film thermal sta-bility.Contrast analysis showed that HY and LS saved better overall performance of low ammonia CNRL,where HY low ammonia CNRL was suitable for the production of foam products,adhesives,etc.,while LS low ammonia CNRL was suitable for the production of gloves,balloons and other pure rubber impregnated products.