CAJ | 학술논문

采用毛细管流变仪考察了温度、剪切速率、预热时间对聚乳酸（PLA）、聚丙烯（PP）、低密度聚乙烯（LDPE）流变性能的影响。结果表明：PLA属切力变稀流体，在210℃时的非牛顿指数为0.68，而该温度下PP的非牛顿指数为0.56，LDPE为0.49；在剪切速率为100~2000s-1时，PLA的黏流活化能为61.51~141.52kJ/mol，PP为14.6~31.92kJ/mol，LDPE为13.89~36.47kJ/mol；在低剪切速率时，增加预热时间不仅使PLA的黏度明显下降，而且使其非牛顿指数和黏流活化能增加，当预热时间从150s增加到300s时，PLA在210℃的非牛顿指数从0.44增加到0.68，剪切速率为100~5000s-1的黏流活化能从32.99~91.67kJ/mol增加到50.40~141.52kJ/mol。
채용모세관류변의고찰료온도、전절속솔、예열시간대취유산（PLA）、취병희（PP）、저밀도취을희（LDPE）류변성능적영향。결과표명：PLA속절력변희류체，재210℃시적비우돈지수위0.68，이해온도하PP적비우돈지수위0.56，LDPE위0.49；재전절속솔위100~2000s-1시，PLA적점류활화능위61.51~141.52kJ/mol，PP위14.6~31.92kJ/mol，LDPE위13.89~36.47kJ/mol；재저전절속솔시，증가예열시간불부사PLA적점도명현하강，이차사기비우돈지수화점류활화능증가，당예열시간종150s증가도300s시，PLA재210℃적비우돈지수종0.44증가도0.68，전절속솔위100~5000s-1적점류활화능종32.99~91.67kJ/mol증가도50.40~141.52kJ/mol。
The rheological properties of poly(lactic acid) (PLA), polypropylene (PP) and low density polyethylene (LDPE) were studied as a function of temperature, shear rate and warm-up time. The results indi-cate that PLA is a shear thinning material, whose non-Newtonian index is 0.68 at 210 ℃, while those of PP and LDPE are 0.56 and 0.49, respectively; meanwhile the viscous flow activation energy of PLA is 61.51-141.52 kJ/mol when the shear rate is 100-2 000 s-1. and for PP and LDPE, they are 14.60-31.92 kJ/mol and 13.89-36.47 kJ/mol, respectively. The viscosity of PLA decreases remarkably while the non-Newtonian index and viscous flow activation energy of PLA rises as the warm-up time increases at low shear rates. The non-Newtonian index of PLA increases from 0.44 to 0.68 when the warm-up time is extended from 150 seconds to 300 seconds at 210 ℃. And the viscous flow activation energy of PLA rises significantly from 32.99-91.67 kJ/mol to 50.40-141.52 kJ/mol with the shear rate in the range of 100-5 000 s-1.