表面活性劑有不同的分(fen)(fen)類(lei)方(fang)法。其(qi)一(yi)是(shi)按(an)(an)離(li)子(zi)類(lei)型分(fen)(fen)類(lei)。將(jiang)表面(mian)(mian)活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)劑(ji)(ji)(ji)(ji)溶于水中(zhong)，按(an)(an)離(li)解(jie)與不離(li)解(jie)，可(ke)分(fen)(fen)為(wei)(wei)離(li)子(zi)型表面(mian)(mian)活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)劑(ji)(ji)(ji)(ji)與非(fei)離(li)子(zi)型表面(mian)(mian)活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)劑(ji)(ji)(ji)(ji)。離(li)子(zi)型表面(mian)(mian)活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)劑(ji)(ji)(ji)(ji)又可(ke)按(an)(an)產生電荷的性(xing)(xing)(xing)(xing)(xing)質分(fen)(fen)為(wei)(wei)陰離(li)子(zi)型、陽離(li)子(zi)型和兩性(xing)(xing)(xing)(xing)(xing)型。其(qi)二是(shi)按(an)(an)溶解(jie)性(xing)(xing)(xing)(xing)(xing)分(fen)(fen)類(lei)，分(fen)(fen)為(wei)(wei)水溶性(xing)(xing)(xing)(xing)(xing)表面(mian)(mian)活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)劑(ji)(ji)(ji)(ji)與油(you)溶性(xing)(xing)(xing)(xing)(xing)表面(mian)(mian)活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)劑(ji)(ji)(ji)(ji)。其(qi)三是(shi)按(an)(an)分(fen)(fen)子(zi)量分(fen)(fen)類(lei)，分(fen)(fen)為(wei)(wei)低(di)分(fen)(fen)子(zi)表面(mian)(mian)活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)劑(ji)(ji)(ji)(ji)與高分(fen)(fen)子(zi)表面(mian)(mian)活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)劑(ji)(ji)(ji)(ji)。其(qi)四是(shi)按(an)(an)用途(tu)分(fen)(fen)類(lei)，分(fen)(fen)為(wei)(wei)潤(run)濕劑(ji)(ji)(ji)(ji)、乳(ru)化劑(ji)(ji)(ji)(ji)、抗靜電劑(ji)(ji)(ji)(ji)、柔軟劑(ji)(ji)(ji)(ji)、勻染(ran)劑(ji)(ji)(ji)(ji)等。

表(biao)(biao)面(mian)活性(xing)(xing)劑分(fen)(fen)子結(jie)構(gou)的特征，是(shi)包括性(xing)(xing)質完全不同(tong)(tong)的兩部分(fen)(fen)，一部分(fen)(fen)是(shi)與油有親(qin)(qin)和性(xing)(xing)的親(qin)(qin)油基(ji)，另一部分(fen)(fen)是(shi)與水(shui)有親(qin)(qin)和性(xing)(xing)的親(qin)(qin)水(shui)基(ji)。不同(tong)(tong)品種的表(biao)(biao)面(mian)活性(xing)(xing)劑，其親(qin)(qin)水(shui)性(xing)(xing)與親(qin)(qin)油性(xing)(xing)的強弱是(shi)不同(tong)(tong)的。表(biao)(biao)面(mian)活性(xing)(xing)劑的一個重要(yao)性(xing)(xing)能指(zhi)標(biao)是(shi)親(qin)(qin)水(shui)親(qin)(qin)油平衡值(zhi)（HLB值(zhi)）。HLB值(zhi)較(jiao)高的表(biao)(biao)面(mian)活性(xing)(xing)劑，其分(fen)(fen)子的親(qin)(qin)水(shui)性(xing)(xing)較(jiao)高，HLB值(zhi)較(jiao)低則表(biao)(biao)示(shi)親(qin)(qin)油性(xing)(xing)較(jiao)高。

幾種表面活性劑(ji)(ji)的HLB值如表3所示(shi)。HLB值在表面活性劑(ji)(ji)的選用中(zhong)有重要意(yi)義。例如，HLB值為(wei)(wei)1~3可作為(wei)(wei)消泡(pao)劑(ji)(ji)，HLB值3~6為(wei)(wei)油包(bao)水型乳(ru)化劑(ji)(ji)，HLB值8~18為(wei)(wei)水包(bao)油型乳(ru)化劑(ji)(ji)，HLB值12~15為(wei)(wei)潤濕劑(ji)(ji)。

表(biao)(biao)面活性劑(ji)(ji)在軟質(zhi)(zhi)PVC中(zhong)的(de)應(ying)用(yong)(yong)，主要是用(yong)(yong)作(zuo)抗靜電劑(ji)(ji)、防霧劑(ji)(ji)、PVC糊降(jiang)粘劑(ji)(ji)等。有關性能將在以下有關部分中(zhong)介(jie)紹。表(biao)(biao)面活性劑(ji)(ji)在軟質(zhi)(zhi)PVC中(zhong)應(ying)用(yong)(yong)時，應(ying)特(te)別注意其對PVC熱(re)穩定性的(de)影響。某些陽離子型(xing)的(de)表(biao)(biao)面活性劑(ji)(ji)對PVC的(de)熱(re)降(jiang)解(jie)有促(cu)進作(zuo)用(yong)(yong)。非(fei)離子型(xing)表(biao)(biao)面活性劑(ji)(ji)則不會引起PVC降(jiang)解(jie)。