Making PVF porous sponge with and without using the pore-forming agent—A comparison

Chang, Yu‐Wei; Yang, Yiying; Cheng, Wei-You; Jang, Larry K.

doi:10.1016/j.jtice.2016.10.025

Cited by 13 publications

(5 citation statements)

References 6 publications

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“…Polyvinyl formal (PVF) is made from polyvinyl alcohol (PVA) and was developed as a hydrophilic sealing material (Nakanishi, 2009, Chang et al, 2017. Figure 4 shows the method for synthesizing PVF.…”

Section: Methodsmentioning

confidence: 99%

Fiber reinforcement of hydrophilic materials for a low-torque shaft seal in water environment

Honda

Nakashima

Higaki

et al. 2018

Mechanical Engineering Letters

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The lips of a shaft seal need to be lubricated to ensure its performance. Such seals are subjected to difficult conditions inside water pumps or underwater mechanical systems. Poor lubrication can cause high friction and wear of seal lips. A new shaft seal was designed to prevent water ingress with low friction and high wear resistance by adopting hydrophilic materials to seal rings. Hydrated composites for seal rings were developed with fibers to avoid excessive deformation. In experiments, cellulose nanofibers were most appropriate for reinforcement of the matrix material and the shaft seal exhibited its sealing performance at the speed of 5000 rpm under pressure of 0.8 MPa. This shaft seal will be useful not only for industrial pumps but also for generation systems driven by water flow, such as ocean current or streamflow.

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Section: Methodsmentioning

confidence: 99%

Fiber reinforcement of hydrophilic materials for a low-torque shaft seal in water environment

Honda

Nakashima

Higaki

et al. 2018

Mechanical Engineering Letters

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“…Poly (vinyl formal) (PVF), the product of the acetalization reaction of PVA with formaldehyde, has interconnected pores and a porous framework, exhibiting the potential supporting material for PEG 25 . Nevertheless, the monolithic PVF foams can just be obtained through the freeze‐drying route after the acetalization reaction, owing to the strong capillary force during the drying process.…”

Section: Introductionmentioning

confidence: 99%

Preparation and characterization of polyethylene glycol‐based form‐stable phase change materials supported by poly (vinyl formal) foams

Chen

Liu

et al. 2022

J of Applied Polymer Sci

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Phase change materials (PCMs) are a kind of materials that provide latent heat at a constant temperature. They have great potential in thermoregulation scopes and thermal energy storage. However, liquid leakage during phase transition restricts their applications in practice severely. In this work, a novel strategy is proposed to prepare form‐stable phase change materials with polyvinyl formal (PVF) foam shape‐stabilized poly (ethylene glycol)‐based material. The PEG exhibits good interfacial compatibility with the PVF framework and the phase transition enthalpy ranges from 104.1 to 158.4 J/g. The PEG/PVF‐C2 increases the residue amount from 0.1% to 4.2% and enhances the thermal degradation temperature at the same time. The mass retention rates of PEG/PVF composites depend on their pore structure, which are 75.4%, 89.5%, and 95.3%, respectively. This study may open a new door for the development of advanced PCMs with good leakage prevention and flame retardancy, thus further contributing to extending the application scopes.

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“…Three methods are generally used for the preparation of PVF foams with good pore structure: [13][14][15][16] addition of a foaming agent, mechanical agitation, and addition of a pore-forming agent. The latter two methods have the disadvantage of being complex processes and also involve a high cost.…”

Section: Introductionmentioning

confidence: 99%

A New Blending Method for the Preparation of Macroporous Open‐cell Polyvinyl Formaldehyde Foams with High Water‐Absorption Capacity

2022

ChemistrySelect

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A new blending method for the preparation of a series of macroporous open‐cell polyvinyl formaldehyde (PVF) foams is reported here. Mechanism of foam‐formation was detailedly analyzed and it was found that the addition of polyvinyl alcohol (PVA) with a low degree of polymerization was important and crucial for the formation of PVF foams. Further, the addition of PVA with a low degree of polymerization is beneficial for the improvement of water solubility. The structures and properties of PVF foams were investigated by Fourier transform infrared (FTIR), scanning electron microscope (SEM), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The macroporous open‐cell PVF foams had a pore size ranging from 120.88 to 16.16 μm with an increased degree of acetalization and the water absorption capacity increased with the addition of PVA with a low degree of polymerization. PVF foams generally have higher thermal stability because of their cross‐linked network structure. The highest water absorption capacity of the PVF foam obtained presently can reach up to 960 wt%, which is much higher than most PVF foams reported so far.

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Making PVF porous sponge with and without using the pore-forming agent—A comparison

Cited by 13 publications

References 6 publications

Fiber reinforcement of hydrophilic materials for a low-torque shaft seal in water environment

Fiber reinforcement of hydrophilic materials for a low-torque shaft seal in water environment

Preparation and characterization of polyethylene glycol‐based form‐stable phase change materials supported by poly (vinyl formal) foams

A New Blending Method for the Preparation of Macroporous Open‐cell Polyvinyl Formaldehyde Foams with High Water‐Absorption Capacity

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