GB/T 33361-2016 in English

《GB/T 33361-2016铁水脱硫喷枪》由TC183（全国钢标准化技术委员会）归口，TC183SC17（全国钢标准化技术委员会冶金非金属矿产品分会）执行，主管部门为中国钢铁工业协会。

Plastics - Phenolic resins - Determination of reactivity on a B-transformation test plate

1 Scope

This standard specifies methods for the determination of the B-transformation time of phenolic resins at a specified temperature and under specified conditions on a B-transformation test plate.

Two methods are described, each with a different B-transformation test plate:

——Method A: Spherical plate with depressions;

——Method B: Flat plate without depressions.

This standard is applicable to resol and novolak containing curing agents.

Note: The B-transformation transition time of phenolic resins on the B-transformation test plate is usually called “condensation rate”.

2 Principle

The condensation of the phenolic resin is carried out to the B-stage on one of two types of test plate.

3 Method A: Determination on a spherical plate with depressions

3.1 Apparatus

3.1.1 Thermostatic control device, permissible temperature variation ± 0.5°C.

3.1.2 Hotplate, on which the test plate can be fixed in a suitable manner to obtain optimum heat transfer.

Note: No hotplate is necessary if a test plate with an integral heater is used.

3.1.3 Glass rod, 5 mm in diameter, tapering to about 2 mm in diameter at one end.

3.1.4 Balance, scale interval 0.01 g.

3.1.5 Syringe.

3.1.6 Stopwatch, with at least 1 s sub-divisions.

3.1.7 B-transformation test plate, with spherical depressions as shown in Figure 1, with or without an integral heater. Suitable melting salts may be used for accurate control of the heater.

Foreword i
1 Scope
2 Principle
3 Method A: Determination on a spherical plate with depressions
4 Method B: Determination on a flat plate without depressions
5 Precision
6 Test report