How is unsaturated polyester resin made?
Unsaturated polyester, any of a group of thermosetting resins produced by dissolving a low-molecular-weight unsaturated polyester in a vinyl monomer and then copolymerizing the two to form a hard, durable plastic material.
What is glass transition epoxy temperature?
Despite the fact that this adhesive cures at room temperature, this epoxy exhibits a high glass transition temperature of 80°C. This system can, however, be heated during cure to achieve a faster set time and superior high-temperature performance.
How do you find the glass transition temperature of a polymer?
There are three general techniques for measuring Tg:
- Differential Scanning Calorimetry (DSC) – This is probably the most traditional and common technique for most polymeric materials.
- Thermal Mechanical Analysis (TMA) – TMA is used to measure Coefficient of Thermal Expansion (CTE) of polymers.
What is Tg of a material?
Glass Transition Temperature (Tg) is the point at which a material alters state – going from a glass-like rigid solid to a more flexible, rubbery compound.
What is the importance of glass transition temperature?
The glass transition temperature, often called Tg, is an important property when considering polymers for a particular end-use. Glass transition temperature is the temperature, below which the physical properties of plastics change to those of a glassy or crystalline state. Above Tg they behave like rubbery materials.
What does a higher Tg mean?
The temperature point is called the glass transition temperature (Tg). The higher Tg point means higher temperature requirement during lamination. The higher of Tg, the better performance of PCB heat resistance, moisture resistance, chemical resistance, stability and other characteristics.
What is Tg value?
The Tg value is the temperature at which amorphous polymers change from hard to soft. The concentration of crystalline regions in amorphous (semicrystalline) polymers affects the rigidity of the polymer. The crystalline melting temperature Tm can be used for quality control and for identification of polymers.
How is the production of unsaturated olyester resins improved?
ABSTRACT The present work aims the characterization of the elements of a polyester reactor and the optimization of Unsaturated Polyester Resins process relating to its polymerization time. It consisted in resolution of problems, evaluation of inherent relations and compilation of equipments and methods.
How is the miscibility of unsaturated polyester determined?
Unsaturated polyesters become insoluble and infusible by crosslinking with a monomer, usually styrene (ST). The commercial resins contain about 3 0-40% by mass of styr- ene. The miscibility of the resin and the styrene depends on the resin composition.
How much styrene is in unsaturated polyester resin?
Experimental The commercial unsaturated polyester resin containing 38 wt.% of styrene, RESAPOL 10-203, was used to prepare mixtures with different styrene concentrations by evapora- tion of the monomer under vacuum and by addition of monomer. Samples with 6, 7, 13, 18, 24, 38 and 58 wt.% of styrene were studied.
What was the early use of polyester resins?
The early polyester resins could be combined with glass fibers for early “Glass Fiber” materials and contact molded into laminates without the need for pressure. However, there were two drawbacks: cure temperatures of at least 100 °C and air inhibition, which led to “tacky” surfaces.