1、Effect and mechanism of modification of particle

In order to increase the mechanical properties of theparticle-gypsum composite, a two-step preparation process including pre-forming molding and moisture-curing was proposedin this study.

2、Modification of urea

Polymeric 4-4 diphenyl methane diisocyanate (pMDI) was blocked with an aqueous sodium bisulfite solution to obtain water-dispersible blocked pMDI (B-pMDI) resin with different HSO3/–NCO mole ratios for the modification of urea-formaldehyde (UF) resin.

3、UREA

In at least one embodiment, the polymer is a urea-formaldehyde resin. The composite material may contain a facing layer on at least one exposed major surface of the composite material.

4、Journal of Applied Polymer Science

FTIR, NMR, XPS, DSC, and TGA analyses showed that the copolymerization formed substituted hydroxymethyl structures. The cross-linking reaction between GUF resin and post-added urea was enhanced, which reduced formaldehyde emission from GUF-bonded plywood to 0.20 mg/L.

5、Modification of Urea

This study aimed to evaluate the effect of small TETA loadings on the properties of urea-formaldehyde (UF) resin and the performance of the resulting plywood. Adhesive mixtures containing 0%, 0.5%, 1.0%, and 1.5% TETA were prepared and characterized in terms of pH, viscosity, solids content, and gel time.

Urea

There may be two ways to enhance phosphorescence performance, one is that the polycondensation of aromatic diamine with urea and formaldehyde promotes spin-orbit coupling, and another is that...

Modification of urea

This study investigated the modification of UF resins of two different formaldehyde/urea (F/U) mole ratios with OS levels, using blocked pMDI (B-pMDI) as a cross-linker for plywood.

Journal of Applied Polymer Science

Based on the requirements of resin-based plugging agents on initial viscosity, gel time and cost, the urea-formaldehyde resin Poly-UF was synthesized via aqueous solution polymerization.

The effect of urea

Modified nanocrystalline cellulose from two kinds of modifiers used for improving formaldehyde emission and bonding strength of urea-formaldehyde resin adhesive

Effect and mechanism of modification of particle

Effect and mechanism of modification of particle-gypsum composites with melamine-urea-formaldehyde resin

In the field of modern building materials, the combination of gypsum powder and urea-formaldehyde resin is a common technical approach. This method not only improves the physical properties of the material but also enhances its environmental performance. This article explores how the addition of urea-formaldehyde resin can modify gypsum powder and analyzes its impact on material properties.

I. Necessity of Modification

With the rapid development of the construction industry, there is a growing demand for higher-performance building materials. While traditional gypsum powder offers good fire resistance and low cost, it has limitations such as low strength, poor crack resistance, and susceptibility to moisture absorption and expansion in humid environments, which can compromise building quality and lifespan. modifying gypsum powder with polymer materials like urea-formaldehyde resin significantly improves its comprehensive properties.

II. Modification Process

1. Pretreatment: Gypsum powder is first cleaned and dried to ensure surface cleanliness and dryness.

2. Mixing: The pretreated gypsum powder is mixed with an appropriate amount of urea-formaldehyde resin at a specific ratio. This step is critical, as it directly affects the final product’s performance.

3. Forming: The mixed material is shaped into desired forms and sizes through processes like casting or pressing.

4. Drying: The formed gypsum is dried at a suitable temperature to remove internal moisture and prevent cracking.

5. Post-Treatment: The dried material may undergo surface treatments such as grinding or coating to enhance its aesthetics and practicality.

III. Analysis of Modification Effects

The modified gypsum powder exhibits the following advantages:

1. Improved Strength: Urea-formaldehyde resin reacts with hydroxyl groups in gypsum powder, forming a three-dimensional cross-linked network that enhances strength and durability.

2. Enhanced Crack Resistance: The cross-linked structure resists crack initiation and propagation under external forces, reducing the risk of fracture.

3. Increased Water Resistance: The addition of urea-formaldehyde resin improves water resistance, which is crucial for moisture-proof applications in buildings.

4. Better Environmental Adaptability: The modified gypsum powder absorbs less moisture in humid conditions, improving weather resistance and prolonging service life.

IV. Practical Applications

In real-world projects, modified gypsum powder is widely used in various construction fields. For example, in external wall insulation systems of high-rise buildings, modified gypsum boards are favored for their excellent insulation and fire resistance. Additionally, modified gypsum powder is applied in interior decoration, flooring, and ceiling systems, providing high-quality options for construction needs.

Modifying gypsum powder with urea-formaldehyde resin enhances its strength, crack resistance, water resistance, and environmental adaptability. This technology offers new opportunities for the development of building materials and contributes to the construction industry. In the future, with advancements in technology and stricter environmental requirements, the integration of gypsum powder and urea-formaldehyde resin will continue to evolve, driving innovation and value in the construction sector.