Polyester resins measurement

ISO 2535-1974(E), Plastics—Unsaturated polyester resins--Measurement of gel time at 25 C. BS 2782, Part 8, Method 835B, Determination of gelation time of polyester resins (manual method), 1980. 

Plastics Unsaturated-polyester resins - Measurement of gel time at ambient temperature 2001... 

Figure 25.9. Typical exotherm curves for polyester resin cured with 1% benzoyl peroxide over a range of bath temperatures. (Test tubes of 19 mm dia are filled to height of 8 cm with a mixture of resin plus peroxide. The tubes are immersed in a glycerin bath to the level of the resin surface. Temperature is measured with a thermocouple needle whose point is half-way down the resin...

Continuous monitoring of the carbon monoxide and carbon dioxide evolved during thermal decomposition of brominated polyester resin samples, has been carried out using a simultaneous thermal analysis-mass spectrometry technique. In order to allow measurement of the carbon monoxide evolved, the atmosphere chosen for these runs was 21% oxygen in argon, since the peak at 28 atomic mass units (amu)... 

Studies of rheokinetics over the whole range of polyester curing is based (as for other materials) on a dynamic method, i.e., on measurements of the time dependence of the dynamic modulus at a fixed frequency, from which the time dependence of the degree of conversion (3(t). The observed dependence P(t) for polyester resins can be analyzed by an equation of the type used for other materials. Thus the following general equation was proposed for the kinetics of curing polyester and epoxy resins 69 72... 

Twenty-eight of fifty-four samples purchased were found to have coatings made from polyester resins and so their contents were analysed for TPA and IPA. Analysis was by GC-MS after extraction and derivatisation to form the dimethyl esters of TPA and IPA. Included in the analytical quality assurance steps taken was participation in a check-sample exercise whereby four samples were supplied by a second laboratory and analysed blind. The performance of the testing laboratory was assessed from the accuracy and precision of their measurements and was demonstrated to be acceptable. 

Two resins were used to do the first study on laminate construction. The first was a brominated epoxy vinyl ester resin with antimony pentoxide and the second was a brominated unsaturated polyester resin. They were both promoted to cure at room temperature with methyl ethyl ketone peroxide catalyst. The panels were then postcured at 250°F (121°C) for 8 h. Panels were prepared that varied in glass content from 25% to 70% and panel thickness varying from 0.05 in. to 0.25 in. and were tested at the same testing facility. A summary of the FSI test data for the first set of panels tested are shown in Figures 23.1 and 23.2. This graph in Figure 23.1 plots the FSI value versus the panel thickness. This data would indicate that the thickness of the test panel has no effect on the measured... 

In spite of the fact that the ccirbon-to-carbon double bonds in the Dow vinyl ester prepolymer chains are structoterminal emd those in the Ashland polyester resin are structopendcmt, the Dow vinyl ester resin is less reactive them the Ashlcuid polyester resin with the same formulation and initiator system. This difference in reactivity or rate of reaction cem be discussed with the aid of the DSC measurements presented above. 

Test tube (M 835B-80) Measure gel time of polyesters Resin test tube at given temperature and volume... 

Monolayer studies were done on a polyester resin-impregnated fiber glass Langmuir trough, 15.1 X 85 cm and 5 mm deep, coated with paraffin. This arrangement was mounted on a lathe bed equipped with a variable speed motor with a tachometer feedback control which drove the Teflon sweeps at 0.65 cm/min, 1%. Surface pressure measurements were made with a platinum Wilhelmy plate coupled to a Cahn RG Electro-... 

Embedded strain gages with 100mm of gage length, were Installed in polyester resin concrete when the specimens were molded. The length change was measured by static strain meter connected with a timer at 20°C, 50 % R.H. The measurements were conducted at Intervals of 5 minutes for 60 minutes after adding the catalyst to... 

Figure 10. Comparison of data on setting shrinkage of polyester resin cotKrete, measured by automatic apparatus and embedded strain gages.

Liquid polyester resins are often used at ambient temperatures, for applications such as glass fiber impregnation, for example, in the manufacture of boats, or for casting purposes. Curing is usually achieved by addition of peroxide initiator and accelerator immediately before use. Measurement of the time to gel, i.e., the time the operator has to impregnate the reinforcement or pour the castings, etc., is of particular relevance. 

ISO 3219. 1993 (75], covers polyester resins as liquids, emulsions, or dispersions using a rotational viscometer, coaxial cylinder viscometer, and cone and plate system. ISO 2555 (76] refers to the Bookfield viscometer. ASTM D1824 [77] covers the use of this instrument for the measurement of apparent viscosity of plastisols and organisols at low shear rates. For high shear rates. ASTM D1823 (78] describes a method using a Burrell Severs A-120 viscometer. ISO 1628 (79] covers determinations of viscosity number and limiting viscosity for PVC, polyolefins, polycarbonate, thermoplastic polyester, and methyl methacrylate polymers, in parts 2 to 6 respectively. 

Pucid, I. and Ranogajec, F. 1995. DC-electrical conductivity as a method for monitoring radiation curing of unsaturated polyester resins. 1. Measurement conditions and comparison with extraction analysis data. Radiat. Phys. Chem. 46 365-370. 

In 1971, one of the first pipes was installed in the UK in London in the form of 1.17 X 0.61 m egg shaped profiles. A polyester felt mat tube impregnated with an isophthalic polyester resin was installed and cured in place. After 20 years, a section of the pipe was taken out of service and the strength properties were measured. The cured-in-place pipe retained its properties and still had a flexural strength that was 30% over the initial installation requirements. The parts showed no sign of wear or deformation. Several other pipe sections have been checked after years of service and found to be virtually unchanged. 

The pultruded GFRP material investigated in [21] was produced by Fiberline Denmark and composed of E-glass fibers embedded in an isophthalic polyester resin (fiber weight fraction 57.6%). Two specimens were prepared as 100 mm square plates with 6 mm thickness. Only the through-thickness thermal conductivity was measured. The hot plate sensor was placed between the two plates and was then heated by an electrical current for a short period of time. The dissipated heat caused... 

The time-dependent evolution of the polymerisation and copolymerisation reactions of styrene/unsaturated polyester resin was characterised using optical levitation with Raman spectroscopy (135). The n-butyllithium-initiated anionic polymerisation of styrene in ethylbenzene was measured using Raman spectroscopy (214). 

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