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In this study, we explore the application of dendrimers in damping modification of chlorinated butyl rubber (CIIR) through molecular dynamics simulation. The dendrimer is dendritic polyamide G2 with polar end groups. The results showed that the composite with 9‐equivalent of G2 exhibited significant damping characteristics. The small difference of solubility indicates that G2 had good compatibility with CIIR. The cohesive energy density and bonding energy are improved. Under the same external force, the hydrogen bond consumes more energy. Besides, the maximum free volume fraction also decreased. The molecular chains of G2/CIIR (9/91) were closer. Thus, the internal friction increased and damping performance was enhanced. In terms of the mechanical properties, the elastic stiffness tensors of the material were almost constant. The glass transition temperature moved to the low‐temperature region. This may indicate a better damping performance in the low‐temperature environment. This study provides a basis for improving CIIR damping performance by using dendrimer.

Polydimethylsiloxane (PDMS) membrane in suitable-fluorinated level have excellent pervaporation performance as well as antibiological contamination performance. The pervaporation membranes with different PDMS/fluorosilane mass ratios, the adsorption and dissolution behaviors of acetone molecules on the membrane surface, as well as the diffusion and permeation behaviors in the membranes are studied by all-atom molecular dynamics simulation (AAMDS). The results show that when the mass ratio of PDMS/fluorosilane is 100/20, the surface solubility of acetone is 11.711 (J cm −3 ) 0.5 , and the interfacial interaction is −16897.0415 kcal mol −1 , both of which are the highest. The results of wide-angle X-ray diffraction (WAXD) showed that there are amorphous regions in the membranes suitable for acetone penetration. The maximum chain spacing of the PDMS/fluorosilane(100/20)_membranes is 10.8482 Å, and the free volume fraction (FFV) is 3.03%, both of which are the largest. The change rate of long-term mean square displacement (MSD) in PDMS/fluorosilane(100/20)_Membrane with time is 0.45269. The Young's modulus E, shear modulus G, volume modulus K, and Poisson's ratio 𝝂 of PDMS/fluorosilane(100/20)_Membrane are 0.3249, 0.4061, 0.0492 GPa and -0.5999, respectively. The elasticity of the membrane enhances the diffusion behavior of acetone molecules, and the self-diffusion coefficient of acetone in the membrane is 0.07545 Å 2 ps −1 .

In this work, the mechanism and optimal ratio of dendritic amino-terminated aromatic polyamide G2 as a damping agent to improve the damping properties of chlorinated butyl rubber (CIIR) are studied. G2 can effectively improve the damping properties of CIIR composite by hydrogen-bonding interactions. The types and quantities of hydrogen bonds in the gradient proportional G2/CIIR_Cell systems are counted, while the contribution of single factor hydrogen bond to the damping characteristics of G2/CIIR composite is explored. Finally, the proportion of G2/CIIR composite with optimal damping properties is selected to be 22/100, which contains 6 𝜶-type hydrogen bonds and 12 𝜷-type hydrogen bonds. Meanwhile, this CIIR composite shows excellent mechanical properties, as well as its glass transition temperature (T g ) is 223.7845 K. Thus, it is a kind of CIIR composite material with high damping properties and wide application prospects.