【天(tian)然(ran)樹脂(zhi)(zhi)和合成樹脂(zhi)(zhi)】天(tian)然(ran)樹脂(zhi)(zhi)和合成樹脂(zhi)(zhi)的區(qu)別(bie) 常見天(tian)然(ran)樹脂(zhi)(zhi)有(you)哪些
常見天然樹脂有哪些
這類物質種類繁多,來源于植物者,主要有松香、大漆、琥珀和瑪樹脂等;來源于(yu)動物(wu)者,主要有(you)蟲(chong)膠,它(ta)是紫膠蟲(chong)的(de)分泌物(wu)。天然樹(shu)脂可根據樹(shu)脂組分、樹(shu)脂形成的(de)歷(li)史進行分類。
按照樹脂(zhi)的基本組分可分為(wei)三大類:①純樹(shu)脂(zhi)(zhi),即由萜類物(wu)質(zhi)及粗香(xiang)(xiang)精油(you)組成(cheng)的(de)樹(shu)脂(zhi)(zhi)狀物(wu)質(zhi)。一般不溶于(yu)(yu)水,而溶于(yu)(yu)有(you)機溶劑,如松香(xiang)(xiang)等(deng)。②含樹(shu)膠(jiao)(jiao)脂(zhi)(zhi)或稱(cheng)樹(shu)膠(jiao)(jiao)樹(shu)脂(zhi)(zhi),是(shi)由多糖類物(wu)質(zhi)組成(cheng),可溶于(yu)(yu)水或遇水溶脹,而不溶于(yu)(yu)醇(chun)及有(you)機溶劑,如乳香(xiang)(xiang)等(deng)。③含油(you)樹(shu)脂(zhi)(zhi)或稱(cheng)香(xiang)(xiang)膠(jiao)(jiao),是(shi)指含有(you)較(jiao)多精油(you)、能(neng)溶于(yu)(yu)油(you)中的(de)樹(shu)脂(zhi)(zhi)。按樹(shu)脂(zhi)(zhi)的(de)形成(cheng)歷史可分為化石樹(shu)脂(zhi)(zhi)、半化石樹(shu)脂(zhi)(zhi)和新鮮(xian)樹(shu)脂(zhi)(zhi)。后(hou)者是(shi)最重要的(de)天(tian)(tian)然(ran)樹(shu)脂(zhi)(zhi)來源。有(you)些天(tian)(tian)然(ran)樹(shu)脂(zhi)(zhi)由最早(zao)集運出(chu)口(kou)的(de)港(gang)口(kou)名稱(cheng)得(de)名,如瑪樹(shu)脂(zhi)(zhi)、柯(ke)巴(ba)樹(shu)脂(zhi)(zhi)等(deng)。
常見天然樹脂
1、松香
從(cong)松(song)樹分(fen)泌的粘稠液體中精制而(er)得。是一種(zhong)透(tou)明脆(cui)性的固體物質(zhi),顏色(se)由(you)微(wei)黃至(zhi)棕紅色(se)。從(cong)其采集方法可分(fen)為脂松(song)香和木(mu)松(song)香。脂松(song)香又稱(cheng)膠松(song)香。從(cong)松(song)香樹干上直(zhi)接割口收集流出的粘稠汁液,稱(cheng)為毛松香;蒸(zheng)出(chu)松(song)節油后(hou),精制便(bian)得到(dao)成品脂松(song)香,其(qi)特點(dian)是顏色淺、酸(suan)值高、軟化點(dian)高。木松(song)香是從殘(can)留(liu)的松(song)香樁或樹(shu)根(gen),經溶劑(ji)萃取(qu)、蒸(zheng)餾分(fen)離揮發(fa)性油后(hou)而制得,質量不如脂松(song)香好。松(song)香的品質由(you)顏色、酸(suan)值、軟化點(dian)等(deng)的不同(tong)而分(fen)級。松(song)香中90%以上為各種同分異構(gou)的松(song)(song)香酸,其余(yu)是這些酸的酯(zhi)類和一些不皂化(hua)(hua)物。松(song)(song)香酸是一種弱酸,可以進行酯(zhi)化(hua)(hua)、皂化(hua)(hua)等反(fan)應;對氧的作用很敏感,氧化(hua)(hua)后使松(song)(song)香顏(yan)色變深,也能聚(ju)合成(cheng)二聚(ju)體;在250~260°C能受熱分解(jie)。松香(xiang)主要用于肥皂、造紙等(deng)工(gong)業(ye),制成各種加工(gong)產品(pin)如(ru)松香(xiang)皂、松香(xiang)酯等(deng)用于涂(tu)料工(gong)業(ye)。松香(xiang)在中(zhong)國產量很(hen)大,主要產于西南(nan)、華南(nan)地(di)區。
2、琥珀
松(song)樹分泌的(de)樹脂在地下長期(qi)埋藏而得到(dao)的(de)一種化石樹脂,多用于珠寶、其他工(gong)藝品。
柯(ke)巴樹脂(zhi)和(he)瑪樹脂(zhi) 從非洲(zhou)和(he)新(xin)(xin)西蘭等(deng)(deng)地的(de)(de)木(mu)本植(zhi)(zhi)物(wu)(wu)分(fen)泌物(wu)(wu)得(de)(de)到的(de)(de)一類樹(shu)(shu)脂(zhi)。根據(ju)產(chan)地和(he)植(zhi)(zhi)物(wu)(wu)來(lai)源(yuan)不同有(you)多種名稱,產(chan)于(yu)非洲(zhou)的(de)(de)有(you)剛果柯(ke)(ke)巴(ba)(ba)(ba)、馬(ma)達加(jia)斯加(jia)柯(ke)(ke)巴(ba)(ba)(ba)等(deng)(deng),產(chan)于(yu)新(xin)(xin)西蘭的(de)(de)有(you)高里(li)柯(ke)(ke)巴(ba)(ba)(ba)等(deng)(deng),產(chan)于(yu)菲律賓的(de)(de)有(you)馬(ma)尼拉(la)柯(ke)(ke)巴(ba)(ba)(ba)等(deng)(deng)。從植(zhi)(zhi)物(wu)(wu)直接采取制得(de)(de)的(de)(de)是軟質柯(ke)(ke)巴(ba)(ba)(ba),如馬(ma)尼拉(la)柯(ke)(ke)巴(ba)(ba)(ba);樹(shu)(shu)木(mu)分(fen)泌物(wu)(wu)長期埋藏于(yu)地下(xia)轉化而成化石樹(shu)(shu)脂(zhi),是硬質柯(ke)(ke)巴(ba)(ba)(ba)或化石柯(ke)(ke)巴(ba)(ba)(ba),如剛果柯(ke)(ke)巴(ba)(ba)(ba)等(deng)(deng),采得(de)(de)的(de)(de)粗樹(shu)(shu)脂(zhi)經(jing)過精制即得(de)(de)各種柯(ke)(ke)巴(ba)(ba)(ba)樹(shu)(shu)脂(zhi)。它們的(de)(de)軟化點(dian)約在 100~300°C,多數約在150°C。柯巴樹(shu)脂的主(zhu)要成分(fen)為(wei)樹(shu)脂酸,瑪樹(shu)脂則(ze)是龍腦香科植物(wu)的分(fen)泌物(wu)。瑪樹(shu)脂和柯巴樹(shu)脂在19世紀(ji)為涂料的原料,現已幾(ji)乎不用。
3、蟲膠
也(ye)稱紫膠(jiao),是印度、馬來西亞(ya)和中國云南等地產的(de)紫膠(jiao)蟲,由于新陳代謝(xie)作用,分泌出的膠(jiao)質(zhi)積累在樹枝上的一種動物質(zhi)樹脂。從樹枝上剝取的分泌物,經過(guo)精制即成為(wei)蟲膠(jiao)片。蟲膠(jiao)能溶(rong)于乙醇。現在在涂料(liao)工業中還(huan)有少(shao)量應(ying)用。
天然樹脂和合成樹脂的區別
1、定(ding)義不同
天然(ran)樹(shu)脂是指由自然(ran)界中動植物(wu)分泌(mi)物(wu)所得的無定形有機物(wu)質(zhi),如松香、琥珀、蟲膠等(deng)。
合成(cheng)樹(shu)脂是(shi)指由簡單(dan)有(you)機物(wu)(wu)(wu)經化學合成(cheng)或某些(xie)天然產(chan)物(wu)(wu)(wu)經化學反應而得(de)到的樹(shu)脂產(chan)物(wu)(wu)(wu)。
2、來(lai)源(yuan)不同
天然樹脂主要來(lai)源(yuan)于植物滲(泌)出物的無定形半(ban)固(gu)體(ti)或固(gu)體(ti)有機物。
合(he)(he)成(cheng)樹(shu)脂是(shi)由人工合(he)(he)成(cheng)的一(yi)類高分子聚合(he)(he)物。
3、特點(dian)不(bu)同(tong)
天然樹脂(zhi)受熱時變軟,并可熔化,在應力(li)作用下有流動的傾向,一般不溶于水,而能(neng)溶于醇、醚、酮及其(qi)他有機溶劑。這(zhe)類物質種(zhong)類繁多,來源于植物者,主要有松(song)香、大漆、琥珀(po)和?瑪(ma)樹(shu)(shu)(shu)脂(zhi)(zhi)(zhi)(zhi)(zhi)等;來(lai)(lai)源(yuan)于動物者(zhe)(zhe),主要(yao)(yao)有蟲膠,它是(shi)紫膠蟲的(de)(de)(de)分泌物。天(tian)(tian)然(ran)(ran)樹(shu)(shu)(shu)脂(zhi)(zhi)(zhi)(zhi)(zhi)可(ke)根據樹(shu)(shu)(shu)脂(zhi)(zhi)(zhi)(zhi)(zhi)組(zu)(zu)分、樹(shu)(shu)(shu)脂(zhi)(zhi)(zhi)(zhi)(zhi)形成(cheng)(cheng)的(de)(de)(de)歷(li)史(shi)進行分類。按照樹(shu)(shu)(shu)脂(zhi)(zhi)(zhi)(zhi)(zhi)的(de)(de)(de)基本組(zu)(zu)分可(ke)分為三(san)大類:①純樹(shu)(shu)(shu)脂(zhi)(zhi)(zhi)(zhi)(zhi),即(ji)由萜類物質(zhi)及粗香(xiang)精(jing)油組(zu)(zu)成(cheng)(cheng)的(de)(de)(de)樹(shu)(shu)(shu)脂(zhi)(zhi)(zhi)(zhi)(zhi)狀物質(zhi)。一(yi)般不(bu)溶(rong)(rong)于水(shui)(shui),而溶(rong)(rong)于有機溶(rong)(rong)劑,如松香(xiang)等。②含(han)樹(shu)(shu)(shu)膠脂(zhi)(zhi)(zhi)(zhi)(zhi)或稱(cheng)(cheng)樹(shu)(shu)(shu)膠樹(shu)(shu)(shu)脂(zhi)(zhi)(zhi)(zhi)(zhi),是(shi)由多(duo)醣(tang)類物質(zhi)組(zu)(zu)成(cheng)(cheng),可(ke)溶(rong)(rong)于水(shui)(shui)或遇水(shui)(shui)溶(rong)(rong)脹,而不(bu)溶(rong)(rong)于醇及有機溶(rong)(rong)劑,如乳(ru)香(xiang)等。③含(han)油樹(shu)(shu)(shu)脂(zhi)(zhi)(zhi)(zhi)(zhi)或稱(cheng)(cheng)香(xiang)膠,是(shi)指含(han)有較多(duo)精(jing)油、能溶(rong)(rong)于油中的(de)(de)(de)樹(shu)(shu)(shu)脂(zhi)(zhi)(zhi)(zhi)(zhi)。按樹(shu)(shu)(shu)脂(zhi)(zhi)(zhi)(zhi)(zhi)的(de)(de)(de)形成(cheng)(cheng)歷(li)史(shi)可(ke)分為化(hua)石樹(shu)(shu)(shu)脂(zhi)(zhi)(zhi)(zhi)(zhi)、半化(hua)石樹(shu)(shu)(shu)脂(zhi)(zhi)(zhi)(zhi)(zhi)和(he)新(xin)鮮樹(shu)(shu)(shu)脂(zhi)(zhi)(zhi)(zhi)(zhi)。后者(zhe)(zhe)是(shi)最重要(yao)(yao)的(de)(de)(de)天(tian)(tian)然(ran)(ran)樹(shu)(shu)(shu)脂(zhi)(zhi)(zhi)(zhi)(zhi)來(lai)(lai)源(yuan)。有些天(tian)(tian)然(ran)(ran)樹(shu)(shu)(shu)脂(zhi)(zhi)(zhi)(zhi)(zhi)由最早集運出口(kou)的(de)(de)(de)港口(kou)名(ming)稱(cheng)(cheng)得名(ming),如?瑪樹(shu)脂、柯(ke)巴樹(shu)脂等(deng)。
合成樹脂為(wei)(wei)(wei)粘稠液(ye)體或加(jia)熱(re)可(ke)軟化的(de)固體,受熱(re)時通常(chang)(chang)有熔(rong)融(rong)(rong)或軟化的(de)溫度范圍,在(zai)外力作用下可(ke)呈塑性(xing)流動狀態(tai),某些性(xing)質與天然樹脂(zhi)(zhi)相(xiang)似。合(he)(he)(he)(he)成(cheng)(cheng)(cheng)樹脂(zhi)(zhi)最重要的(de)應(ying)用是(shi)制造(zao)塑料。為(wei)(wei)(wei)便于加(jia)工(gong)和(he)(he)(he)改善性(xing)能(neng),常(chang)(chang)添加(jia)助劑,有時也直接用于加(jia)工(gong)成(cheng)(cheng)(cheng)形,故常(chang)(chang)是(shi)塑料的(de)同義語。合(he)(he)(he)(he)成(cheng)(cheng)(cheng)樹脂(zhi)(zhi)還是(shi)制造(zao)合(he)(he)(he)(he)成(cheng)(cheng)(cheng)纖維、涂料、膠粘劑、絕(jue)緣材(cai)料等(deng)的(de)基礎原(yuan)料。合(he)(he)(he)(he)成(cheng)(cheng)(cheng)樹脂(zhi)(zhi)種(zhong)類繁(fan)多(duo)。按主(zhu)鏈結構有碳鏈、雜鏈和(he)(he)(he)非碳鏈合(he)(he)(he)(he)成(cheng)(cheng)(cheng)樹脂(zhi)(zhi);按合(he)(he)(he)(he)成(cheng)(cheng)(cheng)反應(ying)特(te)征有加(jia)聚(ju)型(xing)和(he)(he)(he)縮聚(ju)型(xing)合(he)(he)(he)(he)成(cheng)(cheng)(cheng)樹脂(zhi)(zhi)。實際應(ying)用中,常(chang)(chang)按其熱(re)行為(wei)(wei)(wei)分為(wei)(wei)(wei)熱(re)塑性(xing)樹脂(zhi)(zhi)和(he)(he)(he)熱(re)固性(xing)樹脂(zhi)(zhi)。生產(chan)合(he)(he)(he)(he)成(cheng)(cheng)(cheng)樹脂(zhi)(zhi)的(de)原(yuan)料來源(yuan)豐富,早期以煤焦油產(chan)品(pin)和(he)(he)(he)電石乙炔為(wei)(wei)(wei)主(zhu),現多(duo)以石油和(he)(he)(he)天然氣的(de)產(chan)品(pin)為(wei)(wei)(wei)主(zhu),如乙烯、丙烯、苯、甲醛及尿素等(deng)。合(he)(he)(he)(he)成(cheng)(cheng)(cheng)樹脂(zhi)(zhi)的(de)生產(chan)方法采用本體聚(ju)合(he)(he)(he)(he)、懸浮聚(ju)合(he)(he)(he)(he)、乳液(ye)聚(ju)合(he)(he)(he)(he)、溶(rong)液(ye)聚(ju)合(he)(he)(he)(he)、熔(rong)融(rong)(rong)聚(ju)合(he)(he)(he)(he)和(he)(he)(he)界面縮聚(ju)等(deng)。