High thermal conductivity polymer chains with reactive groups: a step towards true application

Abstract

Nanostructured polyethylene (PE, [-CH2-CH2-]n) films with metal-like thermal conductivity have opened the opportunities for polymers in advanced thermal management. However, in practice, polymers used in thermal management are either thermoset...

Enhanced Thermal Conductivity in Oriented Polyvinyl Alcohol/Graphene Oxide Composites

“…In contrast, the drawn PVA films with 5 wt % GO and 1 wt % SDBS show a red-shifted (to lower energies/wavenumbers) peak at ∼3260 cm –1 , indicating the hydrogen bonding interaction between GO and PVA (Figure S7a). ,, Although WAXS results indicate the orientation of the PVA chains, there is no obvious orientation of hydrogen bonding in the polarized FTIR spectra (Figure S7b,c), consistent with a previous literature report . There is a drawing-induced shift to higher energies/wavenumbers of the absorption peak of −OH in both PVA-0 and PVA-5 films in comparison with the undrawn PVA-0 and PVA-5 films, respectively (Figure S7a), as reported as undrawn and drawn polyacrylonitrile and PVA in the literature. , FTIR spectra of pure SDBS powder and the undrawn PVA-0(2) film are shown in Figure S8 as control experiments, and the Raman spectrum confirms the oxidization group-induced defects in the GO powder (Figure S7d).…”

“…Recently, high thermal conductivities in anisotropic polymers, including polyethylene (PE) microfilms and micro/nanofibers, − polyvinyl alcohol (PVA) microfilms, − polyamide nanofibers, and their composite films, have been demonstrated via high degrees of chain orientation, chain extension, and crystallinity. For instance, stretched polyethylene containing graphene nanoplatelets (draw ratio of ∼5) showed a thermal conductivity of ∼6 W m –1 K –1 with a weak van der Waals interaction at the interfaces between the polyethylene and graphene nanoplatelets .…”

State-of-the-art, opportunities, and challenges in bottom-up synthesis of polymers with high thermal conductivity

“…The atomic-level design and synthesis of thermally conductive polymers by bottom-up approaches will provide new opportunities for making polymers with metal-like thermal conductivity, probing relationships between thermal transport properties and structures, and developing theory for better understanding thermal transport mechanisms. 34,44,75 Thermal transport properties in polymers can be manipulated through tuning the monomer composition, 4,9,10,31,[83][84][85] crystallinity, 9,10,37,86,87 molecular weight, [88][89][90][91][92][93] type of crosslink, 88,[94][95][96][97][98][99][100] monomer sequence of the copolymer, 101,102 intrachain and interchain interactions, 13,33,48,97,[103][104][105][106][107][108][109][110][111][112] chain orientation and assembly, 12,<...…”

“…Typical strategies for enhancing efficient thermal transport in polymers are to improve chain orders (e.g., chain alignments and inter-polymer chain packing), 29,56,75,106,128,163,172,[181][182][183][184][185][186] to decrease interface scattering, [187][188][189][190] to increase interchain bonding (e.g., hydrogen bonds and π-π interactions), 13,44,[109][110][111]180,191 and to reduce anharmonicity/bond strength inhomogeneity. 14,146,152,192 Thus, thermally conductive polymers synthesized at monomer levels by various bottom-up approaches have been developed.…”

Sequence-Engineering Polyethylene–Polypropylene Copolymers with High Thermal Conductivity Using a Molecular-Dynamics-Based Genetic Algorithm

“…Furthermore, the genetic-algorithm-cum-molecular-dynamics method is able to capture the subtle improvements. Gratifyingly, it seems possible for the monomer sequence effect on thermal energy transport to be turned toward practical applications using novel monomer chemistries, for example, conjugated 57 and reactive groups, 58 identified during the recent development of polymeric materials with high thermal conductivity. Overall, our work demonstrates that polymer sequence engineering is a promising approach to modulate the thermal conductivity of PE−PP copolymers, and we believe that the computational framework of integrating atomistic MD simulation with the GA has a significant potential for accelerating the design of copolymeric materials.…”