Polyurethanes are polymers which are formed in a reaction between monomers that contain at least two isocyanate (–N=C=O) functional groups and other monomers that contain
Authors:Muhammad Iqbal, Michael McCullough, Adam Harris, and S. Holger Eichhorn
more easily oxidize in air or are protected by organic compounds [ 11 ].
However, experimental studies especially on the thermal conductivity of PMCs containing metal/metal oxide fillers are scarce. Polyurethanes (PUs) containing metal
Authors:Haihua Wang, Yonghao Ni, M. Sarwar Jahan, Zehua Liu, and Thioni Schafer
-biodegradable polymers [ 1 , 2 ]. For instance, lignin as part of the starting material, has been studied to produce different polymers, such as polyurethane (PU) [ 3 – 5 ], phenol-formaldehyde resin [ 6 , 7 ], polyester [ 8 , 9 ]. It can also be used for blending
In this work thermal
transitions and thermal stability of polyurethane intermediates and polyurethanes
were investigated. The intermediates were obtained by glycolysis of waste
polyurethane (PUR) in the reaction with hexamethylene glycol (HDO). The excess
of HDO was not separated from the product after the glycolysis process was
finished. The effects of different mass ratio of HDO to PUR foam on selected
physicochemical properties (hydroxyl number, Brookfield viscosity and density)
were also determined.
The polyurethanes were synthesized from
the obtained intermediates by the prepolymer method using diisocyanate (MDI)
and glycolysis product of molecular mass in range 700/1000 g mol–1.
Hexamethylene glycol, 1,4-butanediol and ethylene glycol were used as chain
extender agents. Influence of NCO groups concentration in prepolymer on glass
transition temperature (Tg)
and storage and loss modulus (E’, E’’) of polyurethanes were investigated
by the DMTA method. Thermal decomposition of obtained glycolysates and polyurethanes
was followed by thermogravimetry coupled with Fourier transform infrared spectroscopy.
Main products of thermal decomposition were identified.
Authors:B. Youssef, B. Mortaigne, M. Soulard, and J. Saiter
In this work, we have studied the degradation processes of polyurethane containing phosphonate groups used as a fireproofing
agent. These studies are undertaken by simultaneous thermogravimetry (TG) and differential scanning calorimetry (DSC) measurements.
It is found that fireproofing agents with phosphonate react with oxygen in the air and prevent the complete combustion of
the material. It is also found that the energy released during combustion is low when comparison is performed with other fireproofing
Equilibrium melting temperatures and crystallization parameters of polyamide 6/polyurethane blends were investigated. Thermal
properties of the crystalline phase of blends obtained from polyamide 6 and polyurethane containing 40 wt% of hard segments,
are only limited influenced by the overall blend compositon. Because from separate measurements single glass transitions for
all samples were estimated, so in the investigated case the blending process may occur mainly between amorphous fraction of
polyamide 6 and the polyurethane or, what is more probable, the polyurethane phase is dispersed in the continuous polyamide
matrix, although some interactions exist.
]. Compared with APP, the microencapsulated APP (MCAPP) coated with MF or UMF resin can be dispersed well in the PP matrix and has lower water solubility. Ni and co-authors have reported microencapsulated ammonium polyphosphate (APP) with polyurethane (MCAPP
Authors:W. Sułkowski, A. Danch, M. Moczyński, A. Radoń, A. Sułkowska, and J. Borek
Granulated rubber obtained from used tyres, below 1.5 mm granularity (fine rubber) and polyurethane prepolymers (Chemolan
M, Chemolan M50 and Chemolan B3) were used for the synthesis of rubber waste-polyurethane composites, containing 90, 85, 80,
75 and 70%w/w of fine rubber. The influence of the kind of polyurethane resin on hardness, elasticity, glass transition temperature and
thermal stability of composites was studied. Kinetic parameters of the thermal degradation process of composites were calculated
from thermogravimetric analysis (TG) data.
Authors:Y. A. El-Shekeil, S. M. Sapuan, A. Khalina, E. S. Zainudin, and O. M. Al-Shuja'a
are hydrophilic, which causes lack of adhesion and wettability. Therefore, fiber treatments, coupling agents and binders in the interface are used for a better adhesion. In this study, the researchers exploit the hydrophilicity of polyurethane that is
Authors:P. Albu, C. Bolcu, Gabriela Vlase, N. Doca, and T. Vlase
Polyurethane (PU) is a class of extremely versatile technopolymers. Unfortunately, a prolonged service duration is compulsory connected with the necessity of PU’s thermo- and photostabilization due to a rapid self