| 1. |
- Glauser, T., et al.
(författare)
-
A comparison of radiation and thermal curing of thick composites
- 2000
-
Ingår i: Macromolecular materials and engineering. - 1438-7492 .- 1439-2054. ; 274:1, s. 25-30
-
Tidskriftsartikel (refereegranskat)abstract
- This work aimed to compare three different techniques to cure thick composite matrices to see the effect of the process on the network and the thermomechanical properties of the polymer matrix. Two different thermoset resins. one acrylate and one methacrylate, have been free-radically cured with high-energy electron beam (EB), ultra-violet light (UV) ol heat (thermal). The differences in curing mechanisms as well as the thermomechanical properties of the cured resins have been investigated. For this type of resins, EB-cured samples showed the highest thermo-mechanical properties and the lowest residual unsaturation. Thermally cured resins showed similar properties, but with drawbacks such as long curing cycles and thermal degradation in the matrix. The cure did not proceed to the same extent in the UV-cured samples. But the simplicity of the curing equipment makes UV-curing an interesting complement to thermal or EB-curing.
|
|
| 2. |
- Glauser, T., et al.
(författare)
-
Electron-beam curing of thick thermoset composites : Effect of temperature and fiber
- 2000
-
Ingår i: Macromolecular materials and engineering. - 1438-7492 .- 1439-2054. ; 274:1, s. 20-24
-
Tidskriftsartikel (refereegranskat)abstract
- Electron-beam curing of thermoset resins used in fiber-reinforced composites has been investigated. Two resins, a bisphenol-A acrylate and methacrylate, were used as model systems. The temperature was monitored during cure to know the thermal history of the composite during cure. The thermo-mechanical properties were measured on the cured samples. It could be seen that all these values were influenced by the nature (glass or carbon) and amount (0-50 wt.-%) of fiber. A linear correlation was found between the maximum temperature during cure and the glass transition temperature. It was shown that it is possible to compensate for alack of heat during dire in systems with too low exotherms. Some influence on the network homogeneity was also noticed when the thermal energy available during cure was too low.
|
|
| 3. |
- Glauser, T., et al.
(författare)
-
Toughening of electron-beam cured acrylate resins
- 2000
-
Ingår i: Macromolecular materials and engineering. - 1438-7492 .- 1439-2054. ; 280:08-jul, s. 20-25
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to improve the toughness of EB-cured acrylate thermost resins by using hyperbranched aliphatic polyesters as additives to obtain a liquid-liquid phase-separated resin. The hyperbranched polyester can be considered as a hydroxyl functional scaffold, on which functional groups were reacted by control phase separation and crosslinking. Alkyl chains of different lengths attached to the scaffold controlled phase separation. The amount of crosslinking within the rubbery particle and between the particles and the matrix was set by the percentage of methacrylate groups. A good phase separation was obtained; therefore, T-g decreased only slightly compared to the pure acrylate. The K-IC value of the cured resins was increased by 30%. The phase-separated resins showed stability with time and no significant increase in particle size was noticed after 18 months.
|
|
| 4. |
- Johansson, Mats K. G., et al.
(författare)
-
Radiation curing of hyperbranched polyester resins
- 2000
-
Ingår i: Journal of Applied Polymer Science. - 0021-8995 .- 1097-4628. ; 75:5, s. 612-618
-
Tidskriftsartikel (refereegranskat)abstract
- A research area that has obtained increasing interest during the last decade concerns improvement of macromolecular properties by changes in the macromolecular architecture. One group of these materials is dendritic polymers, which are highly branched structures exhibiting very different properties compared with linear polymers. One potential application for these polymers is as radiation curable thermoset resins. This article describes a study where the use of an aliphatic hyperbranched polyester as a base for new radiation curable thermoset resins. The hyperbranched polyesters have been characterized with respect to cure rate and final mechanical properties compared with conventional resins. It is shown that hyperbranched polyesters can be used as versatile scaffolds for various radiation curable resin structures.
|
|
