表面活性劑有(you)不(bu)同的分(fen)(fen)類(lei)方法(fa)。其(qi)一是按(an)離(li)子(zi)(zi)類(lei)型(xing)(xing)分(fen)(fen)類(lei)。將(jiang)表(biao)面(mian)(mian)(mian)活(huo)(huo)性(xing)(xing)(xing)劑(ji)(ji)(ji)(ji)溶于水中(zhong)，按(an)離(li)解與(yu)不(bu)離(li)解，可(ke)分(fen)(fen)為離(li)子(zi)(zi)型(xing)(xing)表(biao)面(mian)(mian)(mian)活(huo)(huo)性(xing)(xing)(xing)劑(ji)(ji)(ji)(ji)與(yu)非離(li)子(zi)(zi)型(xing)(xing)表(biao)面(mian)(mian)(mian)活(huo)(huo)性(xing)(xing)(xing)劑(ji)(ji)(ji)(ji)。離(li)子(zi)(zi)型(xing)(xing)表(biao)面(mian)(mian)(mian)活(huo)(huo)性(xing)(xing)(xing)劑(ji)(ji)(ji)(ji)又可(ke)按(an)產生(sheng)電荷(he)的性(xing)(xing)(xing)質分(fen)(fen)為陰離(li)子(zi)(zi)型(xing)(xing)、陽離(li)子(zi)(zi)型(xing)(xing)和(he)兩性(xing)(xing)(xing)型(xing)(xing)。其(qi)二是按(an)溶解性(xing)(xing)(xing)分(fen)(fen)類(lei)，分(fen)(fen)為水溶性(xing)(xing)(xing)表(biao)面(mian)(mian)(mian)活(huo)(huo)性(xing)(xing)(xing)劑(ji)(ji)(ji)(ji)與(yu)油溶性(xing)(xing)(xing)表(biao)面(mian)(mian)(mian)活(huo)(huo)性(xing)(xing)(xing)劑(ji)(ji)(ji)(ji)。其(qi)三是按(an)分(fen)(fen)子(zi)(zi)量分(fen)(fen)類(lei)，分(fen)(fen)為低(di)分(fen)(fen)子(zi)(zi)表(biao)面(mian)(mian)(mian)活(huo)(huo)性(xing)(xing)(xing)劑(ji)(ji)(ji)(ji)與(yu)高分(fen)(fen)子(zi)(zi)表(biao)面(mian)(mian)(mian)活(huo)(huo)性(xing)(xing)(xing)劑(ji)(ji)(ji)(ji)。其(qi)四是按(an)用途分(fen)(fen)類(lei)，分(fen)(fen)為潤(run)濕劑(ji)(ji)(ji)(ji)、乳化劑(ji)(ji)(ji)(ji)、抗靜電劑(ji)(ji)(ji)(ji)、柔軟劑(ji)(ji)(ji)(ji)、勻(yun)染劑(ji)(ji)(ji)(ji)等。

表(biao)面(mian)活(huo)性(xing)(xing)(xing)劑分子結構的(de)(de)特(te)征，是包括性(xing)(xing)(xing)質完全(quan)不(bu)同(tong)的(de)(de)兩部分，一(yi)(yi)部分是與油(you)有(you)親(qin)(qin)和(he)性(xing)(xing)(xing)的(de)(de)親(qin)(qin)油(you)基(ji)，另(ling)一(yi)(yi)部分是與水有(you)親(qin)(qin)和(he)性(xing)(xing)(xing)的(de)(de)親(qin)(qin)水基(ji)。不(bu)同(tong)品種的(de)(de)表(biao)面(mian)活(huo)性(xing)(xing)(xing)劑，其親(qin)(qin)水性(xing)(xing)(xing)與親(qin)(qin)油(you)性(xing)(xing)(xing)的(de)(de)強弱(ruo)是不(bu)同(tong)的(de)(de)。表(biao)面(mian)活(huo)性(xing)(xing)(xing)劑的(de)(de)一(yi)(yi)個重要(yao)性(xing)(xing)(xing)能指(zhi)標是親(qin)(qin)水親(qin)(qin)油(you)平衡(heng)值(zhi)(zhi)（HLB值(zhi)(zhi)）。HLB值(zhi)(zhi)較高的(de)(de)表(biao)面(mian)活(huo)性(xing)(xing)(xing)劑，其分子的(de)(de)親(qin)(qin)水性(xing)(xing)(xing)較高，HLB值(zhi)(zhi)較低(di)則表(biao)示親(qin)(qin)油(you)性(xing)(xing)(xing)較高。

幾種表面活性劑(ji)的HLB值(zhi)如表3所示。HLB值(zhi)在(zai)表面活性劑(ji)的選用中有重要(yao)意義。例如，HLB值(zhi)為(wei)1~3可作為(wei)消泡劑(ji)，HLB值(zhi)3~6為(wei)油(you)包水(shui)(shui)型乳(ru)(ru)化劑(ji)，HLB值(zhi)8~18為(wei)水(shui)(shui)包油(you)型乳(ru)(ru)化劑(ji)，HLB值(zhi)12~15為(wei)潤(run)濕劑(ji)。

表面(mian)活(huo)(huo)性(xing)(xing)劑(ji)(ji)在軟質PVC中(zhong)的(de)(de)應(ying)用(yong)，主要是(shi)用(yong)作抗靜電劑(ji)(ji)、防霧劑(ji)(ji)、PVC糊降粘(zhan)劑(ji)(ji)等(deng)。有(you)(you)(you)關性(xing)(xing)能(neng)將在以下有(you)(you)(you)關部分中(zhong)介紹。表面(mian)活(huo)(huo)性(xing)(xing)劑(ji)(ji)在軟質PVC中(zhong)應(ying)用(yong)時(shi)，應(ying)特(te)別注(zhu)意其對(dui)PVC熱穩定性(xing)(xing)的(de)(de)影響。某些陽(yang)離子型(xing)的(de)(de)表面(mian)活(huo)(huo)性(xing)(xing)劑(ji)(ji)對(dui)PVC的(de)(de)熱降解有(you)(you)(you)促進作用(yong)。非(fei)離子型(xing)表面(mian)活(huo)(huo)性(xing)(xing)劑(ji)(ji)則不(bu)會(hui)引起PVC降解。