功能材料
功能材料
공능재료
JOURNAL OF FUNCTIONAL MATERIALS
2012年
16期
2138-2141
,共4页
徐阳%孙志丹%陈晓浪%郭刚%张志斌%胡书春
徐暘%孫誌丹%陳曉浪%郭剛%張誌斌%鬍書春
서양%손지단%진효랑%곽강%장지빈%호서춘
左旋聚乳酸%结晶温度%晶体改性%晶体形貌
左鏇聚乳痠%結晶溫度%晶體改性%晶體形貌
좌선취유산%결정온도%정체개성%정체형모
PLLA%crystallization temperature%crystal modificatoins%crystal morphology
以左旋聚乳酸(PLLA)为原料,制备了无定型PLLA膜及无定型PLLA在不同温度下等温结晶的样品。利用红外光谱(FT-IR)、X射线衍射(XRD)和偏光显微镜(POM)分析了结晶温度的改变对PLLA样品的晶体改性及晶体形貌的影响。研究结果表明,结晶温度的改变对PLLA样品的晶体结构、晶型转变及晶粒形貌特征产生了较大的影响。当结晶温度低于100℃时,PLLA主要以无序的α'-晶型存在;随着结晶温度的增加,PLLA的晶体结构和晶型开始转变,当结晶温度超过120℃后,PLLA主要以α-晶型的形式存在;而当结晶温度在100~120℃范围内,则形成的是α'-与α-晶型PLLA的混合形式存在。另一方面,POM照片测试结果表明,随着结晶温度的升高,PLLA的晶体形貌发生了改变,晶粒尺寸随温度的增加而增加,结晶速度增加,晶粒数量减少,PLLA晶体由α'-向α-晶型发生了转变。
以左鏇聚乳痠(PLLA)為原料,製備瞭無定型PLLA膜及無定型PLLA在不同溫度下等溫結晶的樣品。利用紅外光譜(FT-IR)、X射線衍射(XRD)和偏光顯微鏡(POM)分析瞭結晶溫度的改變對PLLA樣品的晶體改性及晶體形貌的影響。研究結果錶明,結晶溫度的改變對PLLA樣品的晶體結構、晶型轉變及晶粒形貌特徵產生瞭較大的影響。噹結晶溫度低于100℃時,PLLA主要以無序的α'-晶型存在;隨著結晶溫度的增加,PLLA的晶體結構和晶型開始轉變,噹結晶溫度超過120℃後,PLLA主要以α-晶型的形式存在;而噹結晶溫度在100~120℃範圍內,則形成的是α'-與α-晶型PLLA的混閤形式存在。另一方麵,POM照片測試結果錶明,隨著結晶溫度的升高,PLLA的晶體形貌髮生瞭改變,晶粒呎吋隨溫度的增加而增加,結晶速度增加,晶粒數量減少,PLLA晶體由α'-嚮α-晶型髮生瞭轉變。
이좌선취유산(PLLA)위원료,제비료무정형PLLA막급무정형PLLA재불동온도하등온결정적양품。이용홍외광보(FT-IR)、X사선연사(XRD)화편광현미경(POM)분석료결정온도적개변대PLLA양품적정체개성급정체형모적영향。연구결과표명,결정온도적개변대PLLA양품적정체결구、정형전변급정립형모특정산생료교대적영향。당결정온도저우100℃시,PLLA주요이무서적α'-정형존재;수착결정온도적증가,PLLA적정체결구화정형개시전변,당결정온도초과120℃후,PLLA주요이α-정형적형식존재;이당결정온도재100~120℃범위내,칙형성적시α'-여α-정형PLLA적혼합형식존재。령일방면,POM조편측시결과표명,수착결정온도적승고,PLLA적정체형모발생료개변,정립척촌수온도적증가이증가,결정속도증가,정립수량감소,PLLA정체유α'-향α-정형발생료전변。
In this work, amorphous PLLA films and crystalline PLLA samples were prepared at different crys- tallization temperatures (80-160℃). The crystal modifications and crystallization morphologies of PLLA sam- ples were studied by Infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and polarized optical micro- graphs (POM). The results demonstrated that the change of crystallization temperature has a great effect on the crystal structure, phase transition, and crystallization morphology of PLLA. At crystallization temperature 〈100℃, disorder aP-crystal is mainly produced for the crystal structure of PLLA samples; however, at crystal- lization temperature ≥ 120℃, the order a-crystals PLLA are mainly proposed; whe the crystallization tempera- ture is between 100 to 120℃, both a- and a-forms coexist. Besides, the crystal morphologies of PLLA samples were illustrated, and it was found that the crystal size increases and the number of spherulite decreases with in- creasing the crystallization temperature. It was found that the disorder-to-order (a-to a-crystalline form) tran- sition occures with increasing crystallization temperature above 120℃.