橡(xiang)胶(jiao)是指具有可(ke)逆形(xing)变(bian)的高弹性聚合(he)物材料，在室温(wen)下富有弹性，在很小的外(wai)(wai)力作用(yong)下能产生较大(da)形(xing)变(bian)，除去外(wai)(wai)力后能恢复原状。橡(xiang)胶(jiao)属于(yu)(yu)完全(quan)无定型(xing)聚合(he)物，它的玻璃(li)化(hua)转变(bian)温(wen)度（T g）低(di)，分子量往往很大(da)，大(da)于(yu)(yu)几十万。

橡(xiang)(xiang)(xiang)胶(jiao)分(fen)为天(tian)然(ran)橡(xiang)(xiang)(xiang)胶(jiao)与合(he)成橡(xiang)(xiang)(xiang)胶(jiao)二种。天(tian)然(ran)橡(xiang)(xiang)(xiang)胶(jiao)是从橡(xiang)(xiang)(xiang)胶(jiao)树、橡(xiang)(xiang)(xiang)胶(jiao)草等(deng)植(zhi)物中(zhong)提(ti)取胶(jiao)质(zhi)后加(jia)工(gong)制成；合(he)成橡(xiang)(xiang)(xiang)胶(jiao)则由(you)各种单体经聚合(he)反应(ying)而得。橡(xiang)(xiang)(xiang)胶(jiao)制品广泛应(ying)用于工(gong)业或生(sheng)活各方(fang)面。

通(tong)用型(xing)橡(xiang)胶的(de)(de)综合(he)(he)性(xing)(xing)(xing)(xing)能(neng)较好(hao)(hao)，应用广泛(fan)。主要(yao)有：①天(tian)然橡(xiang)胶，从三叶橡(xiang)胶树(shu)的(de)(de)乳(ru)胶制(zhi)(zhi)得，基本化(hua)学(xue)成分为(wei)顺(shun)(shun)(shun)(shun)- 聚(ju)(ju)异戊(wu)二(er)烯(xi)(xi)(xi)(xi)。弹性(xing)(xing)(xing)(xing)好(hao)(hao)，强(qiang)度高，综合(he)(he)性(xing)(xing)(xing)(xing)能(neng)好(hao)(hao)。②异戊(wu)橡(xiang)胶，全(quan)名为(wei)顺(shun)(shun)(shun)(shun)-1，4-聚(ju)(ju)异戊(wu)二(er)烯(xi)(xi)(xi)(xi)橡(xiang)胶，由(you)异戊(wu)二(er)烯(xi)(xi)(xi)(xi)制(zhi)(zhi)得的(de)(de)高顺(shun)(shun)(shun)(shun)式合(he)(he)成橡(xiang)胶，因其结构和(he)性(xing)(xing)(xing)(xing)能(neng)与(yu)天(tian)然橡(xiang)胶近(jin)似，故又称合(he)(he)成天(tian)然橡(xiang)胶。③丁(ding)苯橡(xiang)胶，简称SBR，由(you)丁(ding)二(er)烯(xi)(xi)(xi)(xi)和(he)苯乙烯(xi)(xi)(xi)(xi)共聚(ju)(ju)制(zhi)(zhi)得。按(an)生(sheng)产方法分为(wei)乳(ru)液聚(ju)(ju)合(he)(he)丁(ding)苯橡(xiang)胶和(he)溶液聚(ju)(ju)合(he)(he)丁(ding)苯橡(xiang)胶。其综合(he)(he)性(xing)(xing)(xing)(xing)能(neng)和(he)化(hua)学(xue)稳定性(xing)(xing)(xing)(xing)好(hao)(hao)。④顺(shun)(shun)(shun)(shun)丁(ding)橡(xiang)胶，全(quan)名为(wei)顺(shun)(shun)(shun)(shun)式-1，4-聚(ju)(ju)丁(ding)二(er)烯(xi)(xi)(xi)(xi)橡(xiang)胶，简称BR，由(you)丁(ding)二(er)烯(xi)(xi)(xi)(xi)聚(ju)(ju)合(he)(he)制(zhi)(zhi)得。与(yu)其他通(tong)用型(xing)橡(xiang)胶比，硫化(hua)后的(de)(de)顺(shun)(shun)(shun)(shun)丁(ding)橡(xiang)胶的(de)(de)耐(nai)(nai)(nai)(nai)寒(han)性(xing)(xing)(xing)(xing)、耐(nai)(nai)(nai)(nai)磨性(xing)(xing)(xing)(xing)和(he)弹性(xing)(xing)(xing)(xing)特(te)别优异，动(dong)负荷下发热少，耐(nai)(nai)(nai)(nai)老化(hua)性(xing)(xing)(xing)(xing)能(neng)好(hao)(hao)，易与(yu)天(tian)然橡(xiang)胶、氯丁(ding)橡(xiang)胶、丁(ding)腈橡(xiang)胶等并用。⑤氯丁(ding)橡(xiang)胶，简称CR，由(you)氯丁(ding)二(er)烯(xi)(xi)(xi)(xi)聚(ju)(ju)合(he)(he)制(zhi)(zhi)得。具(ju)有良好(hao)(hao)的(de)(de)综合(he)(he)性(xing)(xing)(xing)(xing)能(neng)，耐(nai)(nai)(nai)(nai)油、耐(nai)(nai)(nai)(nai)燃、耐(nai)(nai)(nai)(nai)氧(yang)化(hua)和(he)耐(nai)(nai)(nai)(nai)臭(chou)氧(yang)。但其密度较大(da)，常温(wen)下易结晶变硬，贮存(cun)性(xing)(xing)(xing)(xing)不好(hao)(hao)，耐(nai)(nai)(nai)(nai)寒(han)性(xing)(xing)(xing)(xing)差。