添加剂相互作用对大庆油品氧化性能的影响

EFFECTS OF INTERACTIONS AMONG ADDITIVES ON ANTIOXIDATION PERFORMANCE OF DAQING LUBE STOCK

采用薄膜氧化试验考察了清净剂、无灰分散剂与二烷基二硫代磷酸锌(ZDDP)相互作用对大庆汽油机油抗氧化性能的影响.在二元组分中,磺酸盐会降低ZDDP的抗氧化效果,其中高碱度磺酸盐尤为显著;硫化烷基酚盐能增加ZDDP的抗氧化效果,其中中碱度酚盐更为突出;水杨酸盐仅在用量适宜时才不影响ZDDP的抗氧化效果;丁二酰亚胺能改善ZDDP的抗氧化效果.在三元组分中,在ZDDP与无灰分散剂共存的情况下,清净剂对ZDDP抗氧化性能的影响与上述结果相同,唯高碱度酚盐能降低ZDDP的抗氧化效果.在四元组分中,ZDDP与无灰分散剂共存并与两种清净剂复合,中碱度酚盐分别与高碱度磺酸盐、水杨酸盐复合部获得了优良的抗氧化效果;而水杨酸盐分别与高碱度磺酸盐、高碱度酚盐复合则降低ZDDP的抗氧化效果.采用动态氧化试验考察了清净剂与无灰分散剂对ZDDP作用机理的影响.清净剂能增强ZDDP终止游离基的功能,但降低了它分解ROOH的能力;无灰分散剂对ZDDP两种作用机理的影响不显著.

The effects of interactions among ashless dispersant, detergents and ZDDP on antioxidation performance have been investigated with the thin film oxygen uptake test(TFOUT). The results show that, in two-additive system, sulfonate salt reduces ZDDP's antioxidation performance,and overbased sulfonate salt affects heavily; sulfide alkylphenate salt enhances ZDDP's antioxidation performance, while medium-based alkylphenate salt is much better. Alkylsalicylate salt does not affect ZDDP's performance only when proper concentration is used. Interaction of ZDDP with succinimide has some synergistic effect on ZDDP. In three-additive system, with the existence of ZDDP and succinimide, effects of detergents on ZDDP are the same as mentioned before. Only overbased alkylphenate salt reduces ZDDP's antioxidation effect. In four-additive system, with the existence of ZDDP and succinimide complexed with two kinds of detergents, much better antioxidation performance is obtained when medium-based alkylphenate salt complexes with overbased sulfonate salt or alkylsalicylate salt. However, when alkylsalicylate salt complexes with overbased sulfonate alkylsalicylate or overbased alkylphenate salt, ZDDP's antioxidation performance is reduced. The interaction mechanism of the effects of detergents and ashless dispersant on ZDDP have been studied with the circulating oxygen absorption oxidation test. The results show that the detergents enhance ZDDP's ability of inhibiting radical,but they reduce ZDDP's ability of decomposing ROOH. Ashless dispersant has no apparent effect on the two interaction mechanisms of ZDDP.