橡(xiang)膠是(shi)指具有可逆形變(bian)的高彈性聚合物(wu)材料，在(zai)(zai)室溫(wen)下富有彈性，在(zai)(zai)很小(xiao)的外(wai)力作用(yong)下能產生較大(da)(da)形變(bian)，除去外(wai)力后能恢復原狀。橡(xiang)膠屬(shu)于完全無定型聚合物(wu)，它的玻璃化轉變(bian)溫(wen)度(du)（T g）低，分子量往往很大(da)(da)，大(da)(da)于幾十萬。

橡(xiang)膠(jiao)(jiao)(jiao)(jiao)分為天(tian)(tian)然(ran)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)與合成橡(xiang)膠(jiao)(jiao)(jiao)(jiao)二種。天(tian)(tian)然(ran)橡(xiang)膠(jiao)(jiao)(jiao)(jiao)是從橡(xiang)膠(jiao)(jiao)(jiao)(jiao)樹、橡(xiang)膠(jiao)(jiao)(jiao)(jiao)草等植物中(zhong)提取膠(jiao)(jiao)(jiao)(jiao)質(zhi)后(hou)加工制成；合成橡(xiang)膠(jiao)(jiao)(jiao)(jiao)則由各種單體(ti)經(jing)聚(ju)合反應而得。橡(xiang)膠(jiao)(jiao)(jiao)(jiao)制品廣泛應用于工業或生活各方面(mian)。

通(tong)(tong)用(yong)型橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)綜合(he)(he)性(xing)(xing)能(neng)較好(hao)，應(ying)用(yong)廣泛(fan)。主要有：①天(tian)(tian)然(ran)(ran)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)，從(cong)三(san)葉橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)樹的(de)乳(ru)膠(jiao)(jiao)(jiao)(jiao)(jiao)制得，基本化(hua)(hua)(hua)學成分為(wei)(wei)順(shun)- 聚(ju)(ju)異戊(wu)(wu)二烯(xi)(xi)。彈性(xing)(xing)好(hao)，強度高(gao)，綜合(he)(he)性(xing)(xing)能(neng)好(hao)。②異戊(wu)(wu)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)，全名為(wei)(wei)順(shun)-1，4-聚(ju)(ju)異戊(wu)(wu)二烯(xi)(xi)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)，由異戊(wu)(wu)二烯(xi)(xi)制得的(de)高(gao)順(shun)式(shi)合(he)(he)成橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)，因其(qi)(qi)結構(gou)和(he)(he)性(xing)(xing)能(neng)與(yu)天(tian)(tian)然(ran)(ran)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)近似，故又(you)稱(cheng)合(he)(he)成天(tian)(tian)然(ran)(ran)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)。③丁(ding)(ding)(ding)(ding)苯(ben)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)，簡(jian)稱(cheng)SBR，由丁(ding)(ding)(ding)(ding)二烯(xi)(xi)和(he)(he)苯(ben)乙烯(xi)(xi)共聚(ju)(ju)制得。按(an)生(sheng)產(chan)方(fang)法分為(wei)(wei)乳(ru)液聚(ju)(ju)合(he)(he)丁(ding)(ding)(ding)(ding)苯(ben)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)和(he)(he)溶液聚(ju)(ju)合(he)(he)丁(ding)(ding)(ding)(ding)苯(ben)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)。其(qi)(qi)綜合(he)(he)性(xing)(xing)能(neng)和(he)(he)化(hua)(hua)(hua)學穩定性(xing)(xing)好(hao)。④順(shun)丁(ding)(ding)(ding)(ding)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)，全名為(wei)(wei)順(shun)式(shi)-1，4-聚(ju)(ju)丁(ding)(ding)(ding)(ding)二烯(xi)(xi)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)，簡(jian)稱(cheng)BR，由丁(ding)(ding)(ding)(ding)二烯(xi)(xi)聚(ju)(ju)合(he)(he)制得。與(yu)其(qi)(qi)他通(tong)(tong)用(yong)型橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)比，硫化(hua)(hua)(hua)后的(de)順(shun)丁(ding)(ding)(ding)(ding)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)的(de)耐(nai)寒性(xing)(xing)、耐(nai)磨(mo)性(xing)(xing)和(he)(he)彈性(xing)(xing)特別優異，動(dong)負荷(he)下發(fa)熱少，耐(nai)老化(hua)(hua)(hua)性(xing)(xing)能(neng)好(hao)，易(yi)與(yu)天(tian)(tian)然(ran)(ran)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)、氯(lv)丁(ding)(ding)(ding)(ding)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)、丁(ding)(ding)(ding)(ding)腈橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)等并用(yong)。⑤氯(lv)丁(ding)(ding)(ding)(ding)橡(xiang)(xiang)(xiang)(xiang)膠(jiao)(jiao)(jiao)(jiao)(jiao)，簡(jian)稱(cheng)CR，由氯(lv)丁(ding)(ding)(ding)(ding)二烯(xi)(xi)聚(ju)(ju)合(he)(he)制得。具有良好(hao)的(de)綜合(he)(he)性(xing)(xing)能(neng)，耐(nai)油、耐(nai)燃、耐(nai)氧(yang)化(hua)(hua)(hua)和(he)(he)耐(nai)臭氧(yang)。但其(qi)(qi)密度較大，常溫下易(yi)結晶變硬，貯存性(xing)(xing)不好(hao)，耐(nai)寒性(xing)(xing)差(cha)。