Fabrication and mechanism of poly(butylene succinate) urethane ionomer microcellular foams with high thermal insulation and compressive feature

AbstractPoly(butylene succinate) (PBS)/polytetrafluoroethylene (PTFE) composites, including three types of PTFE powders, were prepared by melt blending using a HAAKE torque rheometer. Microcellular foams were successfully fabricated by batch foaming with supercritical fluids (scCO2). The effects of PTFE powder type on crystallization, rheological properties and foaming behavior were studied. PTFE L-5 and PTFE JH-220 powders showed good dispersion in the PBS matrix, and PTFE FA-500 powder underwent fibrillation during the melt blending process. All three PTFE powders gradually increased the crystallization temperature of PBS from 78.2 to 91.8 ℃ and the crystallinity from 45.6 to 61.7% without apparent changes in the crystal structure. Rheological results revealed that PBS/PTFE composites had a higher storage modulus, loss modulus, and complex viscosity than those of pure PBS. In particular, the complex viscosity of the PBS/P500 composite increased by an order of magnitude in the low-frequency region. The foamed structure of PBS was obviously improved by adding PTFE powder, and the effect of fibrillated PTFE FA-500 was the most remarkable, with a pore mean diameter of 5.46 μm and a pore density of 1.86 × 109 cells/cm3 (neat PBS foam: 32.49 μm and 1.95 × 107 cells/cm3). Moreover, PBS/P500 foam always guarantees hydrophobicity.

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Lightweight, strong, flame-retardant PVDF/PMMA microcellular foams for thermal insulation fabricated by supercritical CO2 foaming

Composites Part B Engineering ◽

10.1016/j.compositesb.2021.109554 ◽

2022 ◽

Vol 230 ◽

pp. 109554

Author(s):

Zhanlin Shi ◽

Guoqun Zhao ◽

Lei Zhang ◽

Guilong Wang

Keyword(s):

Flame Retardant ◽

Thermal Insulation ◽

Supercritical Co2 ◽

Microcellular Foams

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Supercritical Fluids-Assisted Processing Using CO2 Foaming to Enhance the Dispersion of Nanofillers In Poly(Butylene Succinate)-Based Nanocomposites and the Conductivity

10.21203/rs.3.rs-924056/v1 ◽

2021 ◽

Author(s):

An Huang ◽

Xincheng Song ◽

Fan Liu ◽

Haokun Wang ◽

Lihong Geng ◽

...

Keyword(s):

Electrical Conductivity ◽

Supercritical Fluids ◽

Network Structure ◽

Rapid Development ◽

Conductive Polymer ◽

Critical Index ◽

Multiwalled Carbon ◽

Butylene Succinate ◽

Electrical Percolation ◽

Microcellular Foams

Abstract With the rapid development of electronic information technology, traditional metal conductive materials can no longer satisfy the needs of a wider industry. Poly(butylene succinate)/multiwalled carbon nanotubes (PBS/CNT) conductive polymer nanocomposites with varied CNT content were prepared by a HAAKE torque rheometer. The addition of CNT significantly improved the crystallization, viscoelasticity, and mechanical properties as well as thermal and electrical conductivity. Conductivity of the PBS/CNT nanocomposite with 5 wt.% CNT increased from 8.23×10− 15 S·m− 1 of pure PBS to 33.3 S·m− 1, an increase of 16 orders of magnitude. Moreover, the electrical percolation threshold φc of the PBS/CNT nanocomposites was 2.8 wt.% and the critical index was 1.56, showing that the conductive network structure was between 2D and 3D and 2D network structure dominated. To further improve the conductivity, microcellular foams were successfully fabricated by batch foaming with supercritical fluids (scCO2). The electrical conductivity of the PBS/CNT foam with 5 wt.% CNT reached 67.8 S·m− 1 and it was 104% higher than the corresponding solid nanocomposite.

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High thermal insulation and compressive strength polypropylene microcellular foams with honeycomb structure

Polymer Degradation and Stability ◽

10.1016/j.polymdegradstab.2020.109406 ◽

2020 ◽

pp. 109406

Author(s):

Chenguang Yang ◽

Qiang Zhang ◽

Wenli Zhang ◽

Ming Xia ◽

Kun Yan ◽

...

Keyword(s):

Compressive Strength ◽

Thermal Insulation ◽

Honeycomb Structure ◽

Microcellular Foams

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Influence of Polylactide (PLA) Stereocomplexation on the Microstructure of PLA/PBS Blends and the Cell Morphology of Their Microcellular Foams

Polymers ◽

10.3390/polym12102362 ◽

2020 ◽

Vol 12 (10) ◽

pp. 2362

Author(s):

Zhiyuan Sun ◽

Long Wang ◽

Jinyang Zhou ◽

Xun Fan ◽

Hanghai Xie ◽

...

Keyword(s):

Gas Adsorption ◽

Average Cell Size ◽

Butylene Succinate ◽

Average Cell ◽

Melt Strength ◽

Biological Scaffolds ◽

Microcellular Foams ◽

Microcellular Foaming ◽

Cell Nucleation ◽

Cell Stability

Polylactide foaming materials with promising biocompatibility balance the lightweight and mechanical properties well, and thus they can be desirable candidates for biological scaffolds used in tissue engineering. However, the cells are likely to coalesce and collapse during the foaming process of polylactide (PLA) due to its intrinsic low melt strength. This work introduces a unique PLA stereocomplexation into the microcellular foaming of poly (l-lactide)/poly (butylene succinate) (PLLA/PBS) based on supercritical carbon dioxide. The rheological properties of PLA/PBS with 5 wt% or 10 wt% poly (d-lactide) (PDLA) present enhanced melt strength owing to the formation of PLA stereocomplex crystals (sc-PLA), which act as physical pseudo-cross-link points in the molten blends by virtue of the strong intermolecular interaction between PLLA and the added PDLA. Notably, the introduction of either PBS or PDLA into the PLLA matrix could enhance its crystallization, while introducing both in the blend triggers a decreasing trend in the PLA crystallinity, which it is believed occurs due to the constrained molecular chain mobility by formed sc-PLA. Nevertheless, the enhanced melt strength and decreased crystallinity of PLA/PBS/PDLA blends are favorable for the microcellular foaming behavior, which enhanced the cell stability and provided amorphous regions for gas adsorption and homogeneous nucleation of PLLA cells, respectively. Furthermore, although the microstructure of PLA/PBS presents immiscible sea-island morphology, the miscibility was improved while the PBS domains were also refined by the introduction of PDLA. Overall, with the addition of PDLA into PLA/10PBS blends, the microcellular average cell size decreased from 3.21 to 0.66 μm with highest cell density of 2.23 × 1010 cells cm−3 achieved, confirming a stable growth of cells was achieved and more cell nucleation sites were initiated on the heterogeneous interface.

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