Influence of crosslink density, glass transition temperature and addition of pigment and wax on the scratch resistance of an epoxy coating

1997 ◽  
Vol 69 (9) ◽  
pp. 77-82 ◽  
Author(s):  
Jakob Lange ◽  
Alexandre Luisier ◽  
Anders Hult
1979 ◽  
Vol 52 (1) ◽  
pp. 23-42 ◽  
Author(s):  
A. D. Roberts

Abstract Rubber has been employed in contact with a variety of surfaces for decades, yet the adhesional mechanisms involved are not fully understood. This article describes fundamental investigations carried out over the last decade. Emphasis is placed upon the use of optical techniques for looking directly at the contact area rubber makes with another surface. The interpretation is based upon a rate-dependent surface energy approach. In this way it is possible to predict the level of peel adhesion between surfaces, for example, when a ball rolls on smooth rubber. Other examples treated in the same way are the time for detachment of a ball from a smooth rubber track under gravity, its resilience when bounced on the track, and its friction when slid over the track. The influence of surface roughness, electrostatic forces, surface bloom, and humidity are considered, together with rubber compound variables such as glass transition temperature, crosslink density, and fillers. The central theme is that the adhesional mechanisms all physically depend upon the product of surface properties and bulk viscoelasticity of the solids in contact.


2016 ◽  
Vol 7 (1) ◽  
pp. 36-43 ◽  
Author(s):  
Jin Won Yu ◽  
Jin Jung ◽  
Yong-Mun Choi ◽  
Jae Hun Choi ◽  
Jaesang Yu ◽  
...  

Epoxy nanocomposites are fabricated by using diamine-functionalized GO and exhibit high Tg, tensile strength, and crosslink density.


1997 ◽  
Vol 70 (4) ◽  
pp. 641-649 ◽  
Author(s):  
V. Yu Levin ◽  
S. H. Kim ◽  
A. I. Isayev

Abstract Sulfur-cured non-reinforced SBR with different amounts of poly-, di- and monosulfidic crosslinks is devulcanized by high power ultrasound irradiation in a continuous process under various processing conditions. Total crosslink density, the proportion of polysulfidic crosslinks, gel fraction, and glass transition temperature are measured. The effect of the initial fraction of polysulfidic bonds on the devulcanization process is discussed.


1999 ◽  
Vol 72 (5) ◽  
pp. 854-861 ◽  
Author(s):  
Eduardo A. Gonzalez-de los Santos ◽  
Florentino Soriano-Corral ◽  
Ma Josefina Lozano-Gonzalez ◽  
Rodrigo Cedillo-Garcia

Abstract The present study describes the effect of ultrasonic irradiation on vulcanized guayule rubber using 1 to 3.5 parts per hundred of rubber (phr) of sulfur as the crosslink agent. The effect on crosslink density, gel fraction, torque and glass transition temperature was measured. After exposure to different powers of ultrasonic irradiation, the devulcanization effect was evident on the guayule rubber samples.


Polymer ◽  
2004 ◽  
Vol 45 (6) ◽  
pp. 1939-1950 ◽  
Author(s):  
Jir-Shyr Chen ◽  
Christopher K Ober ◽  
Mark D Poliks ◽  
Yuanming Zhang ◽  
Ulrich Wiesner ◽  
...  

1996 ◽  
Vol 8 (4) ◽  
pp. 579-598 ◽  
Author(s):  
J P Habas ◽  
J Peyrelasse ◽  
M F Grenier-Loustalot

In order to evaluate the thermostability of the IP960 polymer, we have characterized the physicochemical properties of samples exposed at 295 °C for periods up to 3000 h. According to the time of thermal treatment, various phenomena occur such as an increase in glass transition temperature and crosslink density. After a minimal period of 200 h at 295 °C, the weight loss of samples is representative of the degradation of crosslinked IP950. Using FTIR, we have analysed the changes in the chemical structure of the polymer. We propose a mechanism which could explain the degradation of the crosslinked compound.


1972 ◽  
Vol 45 (4) ◽  
pp. 1074-1081 ◽  
Author(s):  
T. Kusano ◽  
Y. Suzuki ◽  
K. Murakami

Abstract Below the glass transition temperature, the cleavage of molecular chains of extended vulcanized rubbers will occur. The crosslink density of vulcanized rubbers, which were placed at room temperature for about 4 h in a nitrogen atmosphere, increased about 17 per cent after extension of 200 per cent at −76° C. This may be due to the recombination of cleft chains, and this can be shown by the Maxwellian type of curves resulting from a plot of crosslink density as a function of forced strain. The decreasing proportion of crosslink density in the presence of radical acceptors in the rubbers and the increasing crosslink density in the absence of radical acceptors, because of recombination of cleft chains, was ascribed to the recombination of unstable chains produced by the added mechanical stimulus.


Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3026
Author(s):  
Gyeongchan Ryu ◽  
Donghyuk Kim ◽  
Sanghoon Song ◽  
Kiwon Hwang ◽  
Wonho Kim

In this study, we examined the feasibility of using epoxidized liquid isoprene rubber (E-LqIR) as a processing aid for truck and bus radial (TBR) tire treads and investigated the effects of the epoxide content on the wear resistance, fuel efficiency, and resistance to extraction of the E-LqIRs. The results confirmed that, compared to the treated distillate aromatic extract (TDAE) oil, the E-LqIRs could enhance the filler–rubber interactions and reduce the oil migration. However, the consumption of sulfur by the E-LqIRs resulted in a lower crosslink density compared to that of the TDAE oil, and the higher epoxide content decreased the wear resistance and fuel efficiency because of the increased glass-transition temperature (Tg). In contrast, the E-LqIR with a low epoxide content of 6 mol% had no significant effect on the Tg of the final compound and resulted in superior wear resistance and fuel efficiency, compared to those shown by TDAE oil, because of the higher filler–rubber interactions.


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