油品與等(deng)體(ti)積的(de)苯胺(an)互相溶(rong)解(jie),成為(wei)單一液相所需的(de)*低溫度即(ji)為(wei)苯胺(an)點。
苯(ben)(ben)胺(an)點(dian)(dian)(dian)可以反映油(you)品(pin)(pin)與橡(xiang)膠(jiao)之(zhi)間(jian)的(de)相容(rong)(rong)性(xing),苯(ben)(ben)胺(an)點(dian)(dian)(dian)越(yue)(yue)(yue)低,油(you)品(pin)(pin)和橡(xiang)膠(jiao)的(de)相容(rong)(rong)性(xing)越(yue)(yue)(yue)差,即油(you)品(pin)(pin)越(yue)(yue)(yue)容(rong)(rong)易(yi)引起橡(xiang)膠(jiao)溶脹。橡(xiang)膠(jiao)溶脹后一般(ban)力學性(xing)能(neng)會大幅下降,所以,需要避免和溶劑(比(bi)如油(you)性(xing)的(de)液體)接觸。實際使用(yong)中(zhong),我們(men)都希(xi)望油(you)品(pin)(pin)不影響橡(xiang)膠(jiao)部件(jian),具有良好的(de)相容(rong)(rong)性(xing),所以,我們(men)需要使用(yong)苯(ben)(ben)胺(an)點(dian)(dian)(dian)測(ce)定(ding)儀預先測(ce)定(ding)油(you)品(pin)(pin)的(de)苯(ben)(ben)胺(an)點(dian)(dian)(dian)。
如果油(you)(you)(you)品里含(han)有的(de)芳(fang)(fang)香烴(jing)較多,則更(geng)容易(yi)溶解苯(ben)胺(an)。因此(ci)苯(ben)胺(an)點(dian)(dian)較高的(de)油(you)(you)(you)品芳(fang)(fang)香烴(jing)含(han)量(liang)較少(shao),對橡(xiang)(xiang)膠(jiao)的(de)溶脹性低。苯(ben)胺(an)點(dian)(dian)低的(de)油(you)(you)(you)品含(han)有的(de)芳(fang)(fang)香烴(jing)較多,更(geng)容易(yi)使橡(xiang)(xiang)膠(jiao)溶脹。在礦物油(you)(you)(you)當中(zhong)(zhong),石蠟基油(you)(you)(you)的(de)苯(ben)胺(an)點(dian)(dian)*高,環烷基油(you)(you)(you)苯(ben)胺(an)點(dian)(dian)居中(zhong)(zhong),芳(fang)(fang)烴(jing)油(you)(you)(you)的(de)苯(ben)胺(an)點(dian)(dian)*低。合成油(you)(you)(you)中(zhong)(zhong),酯類油(you)(you)(you)對橡(xiang)(xiang)膠(jiao)有溶脹作用。