橡膠是指具有(you)可逆形變(bian)的高彈性聚合(he)物材料，在室(shi)溫下富有(you)彈性，在很(hen)小的外力作用下能產生較大形變(bian)，除(chu)去外力后能恢復原(yuan)狀(zhuang)。橡膠屬于完全無定型聚合(he)物，它(ta)的玻璃化(hua)轉變(bian)溫度（T g）低，分子量(liang)往往很(hen)大，大于幾(ji)十萬。

橡(xiang)(xiang)膠(jiao)分為天然橡(xiang)(xiang)膠(jiao)與合成橡(xiang)(xiang)膠(jiao)二種。天然橡(xiang)(xiang)膠(jiao)是從橡(xiang)(xiang)膠(jiao)樹、橡(xiang)(xiang)膠(jiao)草等植物(wu)中提取膠(jiao)質(zhi)后(hou)加(jia)工(gong)制成；合成橡(xiang)(xiang)膠(jiao)則由(you)各(ge)種單體(ti)經(jing)聚合反應而得。橡(xiang)(xiang)膠(jiao)制品廣泛應用于(yu)工(gong)業或生(sheng)活各(ge)方面。

通(tong)用(yong)型橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)綜(zong)(zong)合(he)(he)性(xing)(xing)(xing)能(neng)(neng)較好(hao)(hao)(hao)(hao)(hao)，應用(yong)廣泛。主要有：①天(tian)然橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)，從三(san)葉橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)樹的(de)乳膠(jiao)(jiao)(jiao)(jiao)(jiao)制(zhi)得(de)(de)，基(ji)本(ben)化(hua)學(xue)成分為(wei)(wei)順(shun)(shun)(shun)- 聚(ju)(ju)異戊二烯(xi)(xi)。彈(dan)性(xing)(xing)(xing)好(hao)(hao)(hao)(hao)(hao)，強度高(gao)，綜(zong)(zong)合(he)(he)性(xing)(xing)(xing)能(neng)(neng)好(hao)(hao)(hao)(hao)(hao)。②異戊橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)，全名為(wei)(wei)順(shun)(shun)(shun)-1，4-聚(ju)(ju)異戊二烯(xi)(xi)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)，由異戊二烯(xi)(xi)制(zhi)得(de)(de)的(de)高(gao)順(shun)(shun)(shun)式(shi)合(he)(he)成橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)，因其(qi)結構和(he)(he)性(xing)(xing)(xing)能(neng)(neng)與(yu)天(tian)然橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)近似，故又稱(cheng)合(he)(he)成天(tian)然橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)。③丁(ding)(ding)苯(ben)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)，簡稱(cheng)SBR，由丁(ding)(ding)二烯(xi)(xi)和(he)(he)苯(ben)乙烯(xi)(xi)共聚(ju)(ju)制(zhi)得(de)(de)。按(an)生產(chan)方法分為(wei)(wei)乳液(ye)聚(ju)(ju)合(he)(he)丁(ding)(ding)苯(ben)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)和(he)(he)溶液(ye)聚(ju)(ju)合(he)(he)丁(ding)(ding)苯(ben)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)。其(qi)綜(zong)(zong)合(he)(he)性(xing)(xing)(xing)能(neng)(neng)和(he)(he)化(hua)學(xue)穩(wen)定性(xing)(xing)(xing)好(hao)(hao)(hao)(hao)(hao)。④順(shun)(shun)(shun)丁(ding)(ding)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)，全名為(wei)(wei)順(shun)(shun)(shun)式(shi)-1，4-聚(ju)(ju)丁(ding)(ding)二烯(xi)(xi)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)，簡稱(cheng)BR，由丁(ding)(ding)二烯(xi)(xi)聚(ju)(ju)合(he)(he)制(zhi)得(de)(de)。與(yu)其(qi)他通(tong)用(yong)型橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)比(bi)，硫化(hua)后(hou)的(de)順(shun)(shun)(shun)丁(ding)(ding)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)耐(nai)(nai)寒(han)性(xing)(xing)(xing)、耐(nai)(nai)磨性(xing)(xing)(xing)和(he)(he)彈(dan)性(xing)(xing)(xing)特別(bie)優異，動負荷下發熱少(shao)，耐(nai)(nai)老化(hua)性(xing)(xing)(xing)能(neng)(neng)好(hao)(hao)(hao)(hao)(hao)，易與(yu)天(tian)然橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)、氯丁(ding)(ding)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)、丁(ding)(ding)腈橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)等并用(yong)。⑤氯丁(ding)(ding)橡(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)，簡稱(cheng)CR，由氯丁(ding)(ding)二烯(xi)(xi)聚(ju)(ju)合(he)(he)制(zhi)得(de)(de)。具有良好(hao)(hao)(hao)(hao)(hao)的(de)綜(zong)(zong)合(he)(he)性(xing)(xing)(xing)能(neng)(neng)，耐(nai)(nai)油、耐(nai)(nai)燃、耐(nai)(nai)氧化(hua)和(he)(he)耐(nai)(nai)臭(chou)氧。但(dan)其(qi)密度較大，常溫下易結晶變(bian)硬(ying)，貯存性(xing)(xing)(xing)不(bu)好(hao)(hao)(hao)(hao)(hao)，耐(nai)(nai)寒(han)性(xing)(xing)(xing)差。