摘要
本文讨论了运用溶胀示差扫描量热法(SDSC)测定共聚丙烯腈(PAC)的结晶度.普通的 DSC 法测定聚合物的结晶度只限于熔点低于分解点的聚合物。在加入溶胀剂后,随温度升高,高聚物会由溶胀至溶解,经历完整的结构拆散的过程,这使用 DSC 法测定先分解后熔融聚合物的结晶度成为可能.本文用广角 X 射线衍射法测得 PAC 样品的结晶度(C),用 SDSC 法测得样品的溶胀(溶解)热(AH_T).但 C 与ΔH_T 并不表现出线性关系.从ΔH_T 中扣除样品的 SDSC 曲线温度低端的小峰的热焓(ΔH_1)得到ΔH_T′,C 与ΔH_T′呈现很好的线性关系.应用这一线性关系用 SDSC 法测得另一 PAC 样品的结晶度.与广角 X 射线衍射法测得的结果十分接近.
In this paper,the measurement of crystallinity of acrylic copolymer(PAC),(C),by SwellingDifferential Scanning Calorimetry(SDSC)is discussed.Common DSC is only used for mersuring thecrystallinity of polymers with melting point,(T_m),below their decomposition temperature,(T_d).Astemperature riese,polymers with swelling agent added bocome swollen and dissolved,going throughwhole process of breaking solid structures.Thus,SDSC makes it possible to measure the crystallinity ofpolymers even with T_m below T_d.But,the C measured by WAXD and the total endothermic melting(swelling)heat in SDSC thermograms,(ΔH_r),are not linearly correlated.It has been found that,in-steas of the ΔH_r,the ΔH'_T obtainded from the ΔH_T by subtracting the endothermograms,ΔH_1,and the Cmeasured by WAXD are linearly correlated.On basis of this linear relation,the unknown C of anotherPAC sample is measured by SDSC.The result is in good accordance with that measured by WAXD.
出处
《中国纺织大学学报》
CSCD
1992年第4期30-36,共7页
Journal of China Textile University
关键词
示差扫描
量热法
聚丙烯腈
结晶度
differential scanning calorimetry
polyacrylonitrile
crystallinity
dissolution
swelling
computer applications
computational resolution of overlapping peaks.