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采用紫外光老化和热氧老化2种方法对2种丁苯橡胶(SBR-1502和含20%Si O2的SBR-Si O2)进行老化研究,并利用傅里叶变换红外光谱法、核磁共振波谱法和紫外-可见吸收光谱法对老化产物进行了表征,探究了丁苯橡胶老化机理.结果表明,丁苯橡胶抗紫外光老化能力较差,在紫外光下照射0.5 d,其分子结构即发生明显的改变.而丁苯橡胶的抗热氧能力远远强于它的抗紫外光能力,在140℃下老化5 d后,其结构才发生明显的变化;填料Si O2能有效地提高丁苯橡胶的抗紫外性能;丁苯橡胶在紫外光老化过程中,双键α-H先被氧化成羟基,进而氧化成醛,随着老化时间的延长,最终形成大π键共轭结构,其官能团的紫外老化反应活性顺序依次为:α-H>1,2聚合双键>1,4聚合双键>苯环.
The aging of two types of SBR (SBR-1502 and SBR-Si O2 containing 20% Si O2) was studied by UV aging and thermo-oxidative aging. Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy The aging mechanism of styrene-butadiene rubber (SBR) was investigated by UV-Vis absorption spectroscopy and UV-Vis absorption spectroscopy.The results showed that styrene-butadiene rubber possessed poor UV aging resistance and its molecular structure was observed under ultraviolet light irradiation for 0.5 d Obvious change.However, styrene-butadiene rubber has much better resistance to thermo-oxygen than its UV-resistant ability.After aging for 5 d at 140 ℃, the structure of SBR changed obviously. Rubber UV resistance; styrene-butadiene rubber in the UV aging process, the double bond α-H was first oxidized to hydroxyl, and then oxidized to aldehydes, with the aging time, the final formation of large π bond conjugate structure, the functional group UV aging reactivity sequence: α-H> 1,2 polymerization double bond> 1,4 polymerization double bond> benzene ring.