PDF(Pubmed)
Abstract：
The crystallization behavior of neodymium-based rare earth polybutadiene rubber (Nd-BR) is studied in the presence of small-molecule treated distillate aromatic extract (TDAE) and high-molecular-weight polybutadiene-isoprene copolymer rubber (BIR). Pronounced inhibitory effects on the crystallization of Nd-BR are exhibited by both materials, as evidenced by reductions in the crystallization temperature (Tc), melting point (Tm), and corresponding enthalpy change. It is found that, at equal concentrations, a greater influence on the crystallization rate is exerted by TDAE oils, whereas nucleation inhibition is more potently affected by BIR. Incomplete crystallization during cooling is exhibited by Nd-BR when the TDAE oil concentration reaches 40 parts per hundreds of rubber (PHR) (31 wt.%), or BIR achieves a 60 wt.% concentration; subsequently, a noticeable cold crystallization phenomenon is observed upon heating. Insights into the isothermal crystallization kinetics are offered by the data, which reveal that the Avrami index n value for Nd-BR predominantly ranges between 2.5 and 3.0. A decrease in the n value is induced by a small amount of TDAE oil, while a noticeable decline in the n value is observed only when the BIR concentration is 60 wt.%. A correlation between the crystallization activation energy, the concentration of TDAE oil and BIR, and the crystallization temperature is established; a negative activation energy is recorded, and a decrease in the crystallization rate is noted when both concentrations are low and the crystallization temperature exceeds -50 °C. In contrast, positive activation energy and an increase in the crystallization rate are observed when the BIR concentration reaches 60%, and the crystallization temperature resides between -50 °C and -70 °C.
摘要：
在小分子处理的馏出物芳烃提取物（TDAE）和高分子量聚丁二烯-异戊二烯共聚物橡胶（BIR）存在下，研究了钕基稀土聚丁二烯橡胶（Nd-BR）的结晶行为。两种材料均表现出对Nd-BR结晶的明显抑制作用，结晶温度(Tc)的降低证明了这一点，熔点（Tm），和相应的焓变化。发现,在相等的浓度下，TDAE油对结晶速率的影响更大，而BIR对成核抑制的影响更大。当TDAE油浓度达到40份/数百橡胶（PHR）（31wt。%),或BIR达到60wt。%浓度；随后，在加热时观察到明显的冷结晶现象。数据提供了对等温结晶动力学的见解，这表明Nd-BR的Avrami指数n值主要在2.5到3.0之间。n值的降低是由少量的TDAE油引起的，而仅当BIR浓度为60wt.%.结晶活化能之间的相关性，TDAE油和BIR的浓度，并建立结晶温度；记录负活化能，当两个浓度都很低且结晶温度超过-50°C时，结晶速率降低。相比之下,当BIR浓度达到60％时，观察到正活化能和结晶速率的增加，结晶温度介于-50℃和-70℃之间。
