Author/Authors :
Wang, Chaosheng Donghua University, - State Key Lab for Modification of Chemical Fibers Polymer Materials,, China , Li, Min Donghua University, - State Key Lab for Modification of Chemical Fibers Polymer Materials,, China , Wang, Huaping Donghua University, - State Key Lab for Modification of Chemical Fibers Polymer Materials,, China , Wang, Xiaqin Donghua University, - State Key Lab for Modification of Chemical Fibers Polymer Materials,, China , Filippini-Fantoni, Roberto Sao Bernardo do Campo, Brazil
Abstract :
Based on our previous results of a good agreement between Monte Carlo simulationand DSC measurement for amide interchange reactions (AIRs) duringPA6/PA66 melt blending processes, an improved Monte Carlo model comprisingAIRs, polycondensation, and hydrolysis was established to illustrate the kinetic schemeof randomization for PA6/PA66 blending systems. Validity of the improved Monte Carlomodel which transformed the macro-scale rate constant into a micro-scale rate constantin the simulation was testified by experiments. The effect of blending temperatureon AIRs and the influence of AIRs on degree of transamidation, randomness, regularity,and numberaverage block length of various sequences were analyzed in detail withthe improved Monte Carlo model describing a kinetic process through a pseudorandomnumber. One-order exponential decay (Exp-decay 1) technique was employedto correlate melting points of copolyamides measured by differential scanning calorimeter(DSC) with degree of regularity simulated theoretically with the improved MonteCarlo model. First, the model established direct relationship between the mathematicalsimulation and the experiments then, it was applied to other polyamide blending systemsafter minor alteration of reaction parameter. It was found that degree of randomnessand regularity are independent of blend molar ratio while melting point, molar fractionsof amido linkages and number-average block length are blend molar ratiodependent.
Keywords :
amide interchange reactions , Monte Carlo simulation , PA6 , PA66 blending , block copolymers , randomization.
