實驗步(bu)驟:
1、聚合物試樣(yang)的(de)制(zhi)備
熔融法制備聚(ju)(ju)合(he)物(wu)(wu)球晶(jing)。將少許聚(ju)(ju)合(he)物(wu)(wu)(粒料的(de)(de)1/5左右)放在(zai)干凈(jing)的(de)(de)蓋玻片之間,在(zai)Tm以上 30℃恒(heng)溫(wen) 5min,使(shi)聚(ju)(ju)合(he)物(wu)(wu)充分熔融,并(bing)壓試(shi)樣至薄和(he)排(pai)除氣泡,并(bing)在(zai)稍低于熔點的(de)(de)溫(wen)度結晶(jing),恒(heng)溫(wen)一定時間后冷卻至室溫(wen)。如制備聚(ju)(ju)丙烯(xi)(xi)(PP)和(he)低壓聚(ju)(ju)乙烯(xi)(xi)(HDPE)球晶(jing)時,分別在(zai)230℃和(he)220℃熔融5min,然后PP在(zai)150℃、PE在(zai)120℃保溫(wen)30min,自然降溫(wen),在(zai)不(bu)同的(de)(de)恒(heng)定溫(wen)度下所(suo)得的(de)(de)球晶(jing)形態是(shi)不(bu)同的(de)(de)。
另一(yi)種(zhong)制(zhi)樣(yang)方法是(shi)把聚合(he)物(wu)熔融后馬上淬冷(leng)至(zhi)T,以下得(de)到(dao)無定形態(tai),然(ran)后在高于(yu)T,的某一(yi)溫(wen)(wen)度恒(heng)溫(wen)(wen)一(yi)定時間后,冷(leng)卻至(zhi)室溫(wen)(wen)觀察。
溶(rong)(rong)(rong)(rong)液(ye)法制備聚(ju)(ju)(ju)(ju)合物(wu)球晶(jing)試樣(yang)。先將聚(ju)(ju)(ju)(ju)合物(wu)溶(rong)(rong)(rong)(rong)于(yu)適當的(de)溶(rong)(rong)(rong)(rong)劑(ji)中,然(ran)后緩(huan)慢(man)(man)冷卻,或溶(rong)(rong)(rong)(rong)劑(ji)揮(hui)發使聚(ju)(ju)(ju)(ju)合物(wu)析(xi)出(chu)。常用(yong)(yong)的(de)方法,一種是(shi)把聚(ju)(ju)(ju)(ju)合物(wu)溶(rong)(rong)(rong)(rong)液(ye)滴(di)在與其溶(rong)(rong)(rong)(rong)劑(ji)不相容(rong)的(de)液(ye)體表面,讓溶(rong)(rong)(rong)(rong)劑(ji)緩(huan)慢(man)(man)揮(hui)發后形成薄膜,用(yong)(yong)玻片把薄膜撈起進行觀察。如(ru)把聚(ju)(ju)(ju)(ju)葵二酸乙(yi)二醇(chun)(chun)酯溶(rong)(rong)(rong)(rong)于(yu)100℃的(de)溴苯中,趁熱倒在70℃左右(you)的(de)水面上,控制一定的(de)冷卻速度,冷卻至室溫。另一種方法是(shi)把聚(ju)(ju)(ju)(ju)葵二酸乙(yi)二醇(chun)(chun)酯溶(rong)(rong)(rong)(rong)于(yu)呋喃甲醇(chun)(chun)中 (90℃水浴(yu))配成0.02g/ml 的(de)溶(rong)(rong)(rong)(rong)液(ye)。將幾滴(di)溶(rong)(rong)(rong)(rong)液(ye)滴(di)在玻片上,用(yong)(yong)蓋玻片蓋好,靜置于(yu)有(you)蓋的(de)培養皿中,讓其自然(ran)緩(huan)慢(man)(man)結晶(jing)。
2、熟悉偏光顯微鏡的結構、使用方法及目鏡分度尺的標定方法。
3、將制備好的樣品放在(zai)載(zai)物臺上,在(zai)正(zheng)交偏光(guang)條件下觀察球晶形態(tai),并(bing)測量球晶的半徑。