【摘要】 一、化学降解法作用原理的流变学研究本文在六种商品聚丙烯树脂中,以不同含量的二叔丁基过氧化物（DTBP）降解,进行流变学实验研究。以长径比为0和40的毛细管挤出流变仪和落球粘度计测定流变学参数,包括零切粘度η₀,流动曲线和入口压力降因子e=P₀/2γ。此式中P₀是入口压力降;γ是等切速率下的切应力;e反映入口流动拉伸形变中的可回复应变。 PP系列流变学性质的变化符合无规降解规律。加入10^-5克分子比的DTBP就能使高分子量部分显著减少,大大降低熔体的弹性,由此改善PP在各种加工过程中的性能。更多还原

【Abstract】 Ⅰ. Rheological investigation on chemically degraded PPm elts. Rheological studies performed on six series of commercial PP resins degraded by adding different amounts of organic peroxide-di-tert-butyl peroxide（DTBP）. By means of a capillary extrusion rheometer with capillary length/diameter ratio （L/D= 0 & 40） and a falling sphere viscometer, the following rheological quantities were measured: zero shear rate viscosity η_o, flow curves, and entrance coefficient （ε= P₀/2τ） where P_o is entrance pressure loss and τ is shear stress at same shear rates. Value e is a measure of the recoverable strain of elongation superior deformation in entry flow. The systematic changes of the rheological responses support the random chain scission scheme. It was impressive to find the drastic reduction of elastic strain by adding DTBP of 10^-5mol. ratio of DTBP/PP,which is suggested to be responsible to the improvement of various processing properties of PP plastics by DTBP.更多还原