A novel polyurethane prepolymer as toughening agent: Preparation, characterization, and its influence on mechanical and flame retardant properties of phenolic foam

2012 ◽  
Vol 128 (5) ◽  
pp. 2720-2728 ◽  
Author(s):  
Hongyu Yang ◽  
Xin Wang ◽  
Bin Yu ◽  
Haixia Yuan ◽  
Lei Song ◽  
...  
Keyword(s):  
Flame Retardant ◽  
Phenolic Foam ◽  
Flame Retardant Properties ◽  
Polyurethane Prepolymer ◽  
Toughening Agent

Mechanical and Flame Retardant Properties of Phenolic Foam Modified with Polyethyleneglycol as Toughening Agent

2013 ◽  
Vol 803 ◽  
pp. 21-25 ◽  
Author(s):  
Ming Gao ◽  
Yong Li Yang ◽  
Zhi Qiang Xu
Keyword(s):  
Compressive Strength ◽  
Flame Retardant ◽  
Apparent Density ◽  
Heat Stability ◽  
Test Results ◽  
Phenolic Foam ◽  
Ul 94 ◽  
Flame Retardant Properties ◽  
Toughening Agent ◽  
Limited Oxygen

Polyethyleneglycol (PEG) was used as a as a toughening agent and mixed with the phenolic resin to prepare the foam. The effects of polyethyleneglycol on mechanical and flame retardant properties of phenolic foam were studied by compressive strength, tensile strength, heat stability, scanning electron microscopy (SEM), UL-94 and limited oxygen index (LOI). The apparent density and SEM results showed that the addition of PEG can decrease the apparent density of phenolic foam. The compressive, impact test results showed that the incorporation of PEG into PF dramatically improved the compressive strength, impact strength, indicating the excellent toughening effect of PEG. The LOI of PEG modified phenolic foams remained a high value and the UL-94 results showed all samples can pass V-0 rating, indicating the modified foams still had good flame retardance. The thermal properties of the foams were investigated by thermogravimetric analysis.

scholarly journals Lignin-Based Phenolic Foam Reinforced by Poplar Fiber and Isocyanate-Terminated Polyurethane Prepolymer

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1068
Author(s):  
Guoliang Chen ◽  
Jian Liu ◽  
Wei Zhang ◽  
Yanming Han ◽  
Derong Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Flame Retardant ◽  
Thermal Insulation ◽  
Abrasion Resistance ◽  
Chemical Structures ◽  
Phenolic Foam ◽  
Flame Retardant Properties ◽  
Novel Strategy ◽  
Hybrid Reinforcement ◽  
Polyurethane Prepolymer

Phenolic foams (PFs) are lightweight (<200 kg/m3), high-quality, and inexpensive thermal insulation materials whose heat and fire resistance are much better than those of foam plastics such as polyurethane and polystyrene. They are especially suitable for use as insulation in chemical, petroleum, construction, and other fields that are prone to fires. However, PFs have poor mechanical properties, poor abrasion resistance, and easy pulverization. In this paper, a polyurethane prepolymer was treated with an isocyanate, and then the isocyanate-terminated polyurethane prepolymer and poplar powder were used to prepare modified lignin-based phenolic foams (PUPFs), which improved the abrasion resistance and decreased the pulverization of the foam. The foam composites were comprehensively evaluated by characterizing their chemical structures, surface morphologies, mechanical properties, thermal conductivities, and flame-retardant properties. The pulverization ratio was reduced by 43.5%, and the thermal insulation performance and flame-retardancy (LOI) were improved. Compared with other methods to obtain lignin-based phenolic foam composites with anti-pulverization and flame-retardant properties, the hybrid reinforcement of foam composites with an isocyanate-terminated polyurethane prepolymer and poplar powder offers a novel strategy for an environmentally friendly alternative to the use of woody fibers.

scholarly journals Phenolic Resin Foam Composites Reinforced by Acetylated Poplar Fiber with High Mechanical Properties, Low Pulverization Ratio, and Good Thermal Insulation and Flame Retardant Performance

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 148 ◽  
Author(s):  
Jian Liu ◽  
Liuliu Wang ◽  
Wei Zhang ◽  
Yanming Han
Keyword(s):  
Mechanical Properties ◽  
Flame Retardant ◽  
Thermal Insulation ◽  
Cell Structure ◽  
Value Added ◽  
Chemical Structures ◽  
Phenolic Foam ◽  
Flame Retardant Properties ◽  
Novel Strategy ◽  
Insulation Performance

Phenolic foam composites (PFs) are of substantial interest due to their uniform closed-cell structure, low thermal conductivity, and good thermal insulation performance. However, their disadvantages of a high pulverization rate and poor mechanical properties restrict their application in building exterior insulation. Therefore, the toughening of these composites is necessary. In this paper, poplar fiber was treated with an acetylation reagent, and the acetylated fiber was used to prepare modified phenolic foams (FTPFs); this successfully solved the phenomenon of the destruction of the foam structure due to the agglomeration of poplar fiber in the resin substrate. The foam composites were comprehensively evaluated via the characterization of their chemical structures, surface morphologies, mechanical properties, thermal conductivities, and flame retardant properties. It was found that the compressive strength and compressive modulus of FTPF-5% respectively increased by 28.5% and 37.9% as compared with those of PF. The pulverization ratio was reduced by 32.3%, and the thermal insulation performance and flame retardant performance (LOI) were improved. Compared with other toughening methods for phenolic foam composites, the phenolic foam composites modified with surface-compatibilized poplar fiber offer a novel strategy for the value-added utilization of woody fiber, and improve the toughness and industrial viability of phenolic foam.

The Influence of Formaldehyde/Phenol Ratio on Properties of Foamable Phenolic Resin and Phenolic Foam

2011 ◽  
Vol 250-253 ◽  
pp. 523-527
Author(s):  
Wei Zhang ◽  
Yu Feng Ma ◽  
Fu Xiang Chu ◽  
Chun Peng Wang
Keyword(s):  
Flame Retardant ◽  
Phenolic Resin ◽  
Oxygen Index ◽  
Foam Cell ◽  
Cell Structure ◽  
Molar Ratio ◽  
Free Phenol ◽  
Mixed Acid ◽  
Phenolic Foam ◽  
Flame Retardant Properties

The foamable phenolic resin was prepared by gradual copolymerization of formaldehyde, paraformaldehyde and phenol using sodium hydroxide (NaOH) as catalyst, by way of adding NaOH, paraformaldehyde in different steps. The environmental protection vesicant, foam stabilizer and mixed acid curing agent were mixed with the foamable phenolic resin to prepare flame-retardant insulation phenolic foam. The influence of the formaldehyde/phenol molar ratio on the activity, toxic residue of foamable phenolic resin was investigated. Besides, the foam cell structure, insulation and flame-retardant properties of the phenolic foam were also studied. The results showed that as the molar ratio of formaldehyde to phenol was 2.0, the free phenol content was 2.3% and hydroxymethyl content was 34.83%, the thermal conductivity was 0.046w/mk, oxygen index was 54.3% and carbon monoxide (CO) peak production was as high as 1.8584 kg/kg, which was suitable to be used as insulation and flame-retardant materials in buildings.

Synergistic Effect and Flame-retardant Properties of Small Molecular Organic Amines and Phosphates

2021 ◽  
Author(s):  
Xin Chen ◽  
Junkang Guo ◽  
Limei Ren ◽  
Shenyong Ren ◽  
Baojian Shen ◽  
...  
Keyword(s):  
Synergistic Effect ◽  
Flame Retardant ◽  
Flame Retardant Properties ◽  
Organic Amines

Oxa-Michael polyaddition of vinylsulfonylethanol for aliphatic polyethersulfones

2021 ◽  
Author(s):  
Nicole Ziegenbalg ◽  
Ruth Lohwasser ◽  
Giovanni D’Andola ◽  
Torben Adermann ◽  
Johannes Christopher Brendel
Keyword(s):  
Refractive Index ◽  
High Temperature ◽  
Flame Retardant ◽  
Chemical Resistance ◽  
High Refractive Index ◽  
Industrial Applications ◽  
Interesting Class ◽  
The Common ◽  
Flame Retardant Properties

Polyethersulfones are an interesting class of polymers for industrial applications due to their unusual properties such as a high refractive index, flame-retardant properties, high temperature and chemical resistance. The common...

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