蓖麻油-马来酸酐-苯乙烯双功能润滑油添加剂的合成

Synthesis of Castor Oil-Maleic Anhydride-Styrene Bifunctional Lubricant Additive

传统石油基润滑油添加剂对环境的不利影响,使可生物降解的植物油基润滑油添加剂成为研究热点。以蓖麻油(CO)、马来酸酐(MAH)、苯乙烯(ST)为原料,偶氮二异丁腈(AIBN)为引发剂,甲苯为溶剂,合成了蓖麻油-马来酸酐-苯乙烯共聚物(PCMAS)。通过红外光谱(FT-IR)、核磁共振氢谱(^(1)H NMR)表征了蓖麻油-马来酸酐-苯乙烯共聚物的结构,采用凝胶渗透色谱(GPC)测定了聚合物的相对分子质量及其多分散性指数,采用热重分析研究了聚合物的热稳定性,并对聚合物作为润滑油降凝剂和黏度指数改进剂的性能进行了评价。结果表明:当单体质量比m(CO)∶m(MAH)∶m(ST)=1.0∶0.2∶1.2、引发剂AIBN含量占总单体的0.5%(质量分数)、反应时间4 h、反应温度90℃时,共聚物收率为68.39%,其数均相对分子质量为0.348×10^(5),多分散性指数为4.77。将蓖麻油-马来酸酐-苯乙烯共聚物添加到润滑油馏分(350~395℃)中,可降低润滑油的凝点,并提高其黏度指数。蓖麻油-马来酸酐-苯乙烯共聚物可作为一种具有降凝增黏双重功能的润滑油添加剂。

The adverse effect of traditional petroleum-based lubricant additives on the environment has made the biodegradable lubricant additives become a research hotspot.In the work,poly(castor oil(CO)-maleic anhydride(MAH)-styrene(ST))(PCMAS)was synthesized with azodiisobutyronitrile(AIBN)as the initiator in toluene through Schlenk technology.The structure of PCMAS was characterized by Fourier Transform Infrared spectroscopy(FT-IR)and~1H nuclear magnetic resonance(^(1)H NMR).The relative molecular mass and its polydispersity index of PCMAS were determined by gel permeation chromatography(GPC).Thermo gravimetric analysis method was used to study the thermal stability of the prepared polymers.Performance of the synthesized polymers was evaluated as pour point depressant and viscosity index improver.Experimental results show that the optimum process conditions are as follows:m(CO)∶m(MAH)∶m(ST)is equal to 1.0∶0.2∶1.2,AIBN mass fraction is 0.5%(based on the total mass of monomers),reaction temperature is 90℃,and reaction time is 4 h.Under the above conditions,the copolymer has a yield of 68.39%,the number average relative molecular mass is 0.348×10^(5),and the polydispersity index is 4.77.When the synthesized PCMAS copolymer was added,pour point of lubricant fraction(350—395℃)was decreased and its viscosity index was increased.Therefore,the synthesized PCMAS copolymer could be used as a lubricant additive with double functions of reducing pour point and increasing viscosity index.