Effects of chain extender in biodegradable polyurethane foams

Kang, Suchul; Kang, Moo Seok; Kwon, Sun Hong; Park, Hyun; Kim, Byung Kyu

doi:10.1515/polyeng-2013-0158

Cited by 16 publications

(3 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[25][26][27][28][29][30] Among them, chain extenders are used in minor amounts in the formulation, but can have a serious impact on the final properties of the PU foam. [31][32][33][34][35] Chain extenders are low molecular weight molecules with two, three, four, or more functional groups. The functional group can be alcohol, amine, acid, or other active sites that can react with isocyanate groups.…”

Section: Introductionmentioning

confidence: 99%

Effects of di- and trifunctional chain extenders on the properties of flexible cold-cure polyurethane foams

Sohrabi

2023

Journal of Cellular Plastics

View full text Add to dashboard Cite

In this study, effects of di- and trifunctional chain extenders including ethylene glycol (MEG), ethanolamine (MEA), diethanolamine (DEA), and glycerin (GLY) were investigated. 0.3, 0.6, and 0.9 php (parts per hundred parts of polyol mixture) of the chain extenders were added to the polyol formulation. Then, foam parts were produced by molding. The reaction profile, free rise density (FD), and mechanical properties of the specimens were tested regarding ASTM D7487 test methods. First of all, reaction profiles were affected by the chemical nature of the chain extenders. MEA and DEA which have a primary and secondary amine unit, respectively, accelerated both the polymerization and blow reactions and resulted in faster cream (CT), gel (GT), and end-of-rise time (RT) values. On the other hand, MEG also accelerated GT, but retarded CT. Finally, GLY retarded CT, GT, and RT of foam samples. FD of all samples were almost the same with a slight decrease by increasing the amount of chain extenders. Besides, force-to-crush (FTC) as a measure of closed- or open-cell structure, was investigated. Results showed that incorporating di- and trifunctional chain extenders led to a remarkable increase in FTC values. The influence was more profound with amine-based chain extenders. The effects of chain extenders on the mechanical properties were also studied according to the ASTM D3574. In the compression set test, using difunctional chain extenders up to 0.6 php, improved the performance. But higher amounts reversed the trend. On the other hand, trifunctional chain extenders declined the compression set properties of the foam. The addition of chain extenders dwindled the tensile and tear properties of the foams. However, the reduction was less with difunctional chain extenders.

show abstract

Section: Introductionmentioning

confidence: 99%

Effects of di- and trifunctional chain extenders on the properties of flexible cold-cure polyurethane foams

Sohrabi

2023

Journal of Cellular Plastics

View full text Add to dashboard Cite

show abstract

“…It is known that the PUU properties are strongly deponent on the type of the diisocyanate, polyol and chain extender, reaction conditions, degree of microphase separation, hydrogen bonding properties, copolymer structure, hard and soft phases content. Accordingly, the PUU exhibited excellent properties of high elasticity, huge tensile strength and extra toughness [15][16][17][18][19]. Thus, the PUUs are among the most important polymeric materials gained considerable attention in the last decades, exhibiting functional properties that make them convenient to be exploited in many different fields whether industries or everyday life such as coatings and paints, footwear, textile, elastic fibers, electronics, machinery, biomedical applications like drug delivery, biomedical therapies, biological and membrane science, as well as, many of the biomedical devices such as insulation for prosthetic heart valves, pacemakers, blood pumps, and vessels [20][21][22].…”

Section: Introductionmentioning

confidence: 99%

Better Understanding of the Polymeric Irradiation Using Physico-Electrochemical Characteristics

El-Raheem

Hassan

Khaled

et al. 2021

Preprint

View full text Add to dashboard Cite

Poly (ester-urethane) urea (PEUU) based on ethanolamine as a chain extender contain hydroxyl and amino groups was chemically synthesized using 1,1'-methylenebis(4-isocyanatobenzene) MDI diisocyanates, and castor oil. One step polymerization procedure has been used to complete the PEUU formation and this polymeric target was irradiated with different doses (100, 250, 400 and 600 kGy) of gamma-rays. A full physico-electrochemical characterization package was performed on the solid surfaces, radiated vs non-irradiated, for the better understanding of the structure changes. To that end, Fourier transform infrared spectroscopy (FTIR), and the morphological features were characterized by the scanning electron microscope (SEM). Thermal stability was investigated using the differential scanning calorimetry (DSC), while the crystallinity and electrochemical properties were explored by the X-ray diﬀraction (XRD), and cyclic voltammetry (CV), respectively. Eventually, swelling, crosslinking density, mechanical strength, water absorption and contact angle measurements were discussed. Ultimately, the crosslinking density was discovered to be irradiated dependent. Worth mentioning here, this kind of study is recommended as a protocol that could be applied on other polymeric targets exposed to electromagnetic radiations.

show abstract

“…A large number of studies pertaining to the effect of increasing chain length on material properties of polyurethanes have been reported . Chain extenders with even number of CH 2 groups have been found to exhibit relatively better mechanical properties, as it is possible for different parts of the macromolecular chain to adopt extended linear forms which further enhance the extent of H‐bonding in the polymer …”

Section: Introductionmentioning

confidence: 99%

Spray processable polyurea formulations: Effect of chain extender length on material properties of polyurea coatings

Tripathi

Parthasarathy

Roy

2019

J of Applied Polymer Sci

View full text Add to dashboard Cite

The increasing usage of polyurea coatings has attracted the attention of researchers worldwide. Commercial polyurea formulations contain chain extenders as an essential ingredient, which increases the possibility of intermolecular H-bonding by bringing the urea linkages closer. In this work, we establish the effect of increasing chain length of chain extender on the material properties of the polymer. Different types of chain extender were blended with a long chain diamine and subsequently reacted with an MDI-based isocyanate prepolymer through a reactive spray processing technique. Polyurea coatings containing aromatic chain extenders were found to exhibit higher tensile strength as compared to their aliphatic analogues. Increasing the chain length of the aliphatic chain extender led to a reduction in the mechanical strength. A suitable combination of aromatic and aliphatic chain extender of short length was found to force the macromolecule to orient in such a fashion so as to result in optimal H-bonding. This manifested in terms of improved processability, as confirmed by chemorheological investigations. Fourier transform infrared spectroscopy was used to understand the Hbonded internal structure of the polymer. Optimum H-bonding resulted in improved mechanical properties of the spray-coated polyurea.The structure-property relationship of polyurea can be adjusted primarily by three factors: choice of the monomer pairs, polymer composition, and its final macromolecular architecture. 11 In view of the above, it is possible to design formulations by varying the isocyanates and amines to result in coatings displaying a range of properties. Much like the diisocyanates, aliphatic or aromatic amines and chain Additional Supporting Information may be found in the online version of this article.

show abstract

Effects of chain extender in biodegradable polyurethane foams

Cited by 16 publications

References 21 publications

Effects of di- and trifunctional chain extenders on the properties of flexible cold-cure polyurethane foams

Effects of di- and trifunctional chain extenders on the properties of flexible cold-cure polyurethane foams

Better Understanding of the Polymeric Irradiation Using Physico-Electrochemical Characteristics

Spray processable polyurea formulations: Effect of chain extender length on material properties of polyurea coatings

Contact Info

Product

Resources

About