Optical And Electrical Properties Of Polymer Materials

August 20, 2024

Optical Properties

1. Refractive index

When light enters a second medium from a first medium (except for perpendicular projection), the ratio of the sine of the angle of projection to the sine of the angle of refraction is called the refractive index (rerration index). The refractive index of a medium is generally greater than 1. The same medium has different refractive indices for different wavelengths of light. The refractive index of plastic is usually referred to the sodium yellow light.

Measuring instrument: Abbey refractometer or V-prism refractometer. 2.

2. Transmittance

The light transmittance of a polymer can be expressed as light transmittance or haze.

1) Light transmittance

It is the percentage of the luminous flux through a transparent or translucent polymer or the ratio of the luminous flux of incident light. Transmittance is used to characterize the transparency of a material.

2) Haze

This refers to the cloudy or hazy appearance of the interior or surface of a transparent or semi-transparent polymer due to light scattering. Commonly used forward scattering of the luminous flux and through the luminous flux of the ratio of the percentage expressed, usually measured by integrating sphere type haze meter.

Test standard: GB / T 2410-2008 transparent plastics light transmission and haze test method

3. Gloss

Gloss (gloss) refers to the ability of the plastic surface to reflect light. To plastic specimens in the direction of positive reflection relative to the standard surface reflection of the luminous flux of the ratio of the percentage expressed.

Electrical Properties

1. Dielectric constant

The ratio of the capacitance of a capacitor of the same size made of insulating material as a medium and vacuum as a medium is called dielectric constant (dielectric constant).

Test standard: GB/T 1409-2006 Measurement of the relative dielectric constant and dielectric loss factor of electrical insulating materials in the frequency, audio, high frequency (including meter wave wavelength) under the test method.

2. Dielectric loss

When a sinusoidal voltage is applied to a dielectric, the tangent value of the residual angle δ of the phase angle between the applied voltage and the current of the same frequency, tanδ, is called dielectric loss angle tangent (dielectric loss angle tangent), referred to as dielectric loss.

3. Dielectric strength

Dielectric strength (dielectric strength) is a measure of the ability of materials to resist electrical breakdown, the breakdown voltage value of the specimen and the ratio of the thickness of the specimen, kV/mm.

Withstand voltage value: rapidly increase the voltage to a specified value, stay for a certain period of time after the specimen is not penetrated, the voltage at this time is called the withstand voltage value.

Test standard: GB/T 1408.1-2016 Test Method for Electrical Strength of Solid Insulating Materials Part I Test at Industrial Frequency

4. Insulation resistance

Insulation resistance (insulation resistance) is often expressed in the following three ways.

1) Insulation material resistance

The material to be measured is placed in a standard electrode, and after a given time, the ratio of the voltage applied at both ends of the electrode to the total current between the electrodes is the resistance, which is called the insulation resistance of the material.

2) volume resistivity

The ratio of the potential gradient parallel to the direction of the current through the material to the current density is called volume resistivity, or volume resistance, Ω-m.

3) surface resistivity

The ratio of the potential gradient parallel to the direction of current through the surface of a material to the current per unit width of the surface is called surface resistivity, or surface resistance, Ω for short.

Test standard:

GB/T 10064-2006 Test Method for Insulation Resistance of Solid Insulating Materials

GB/T 1410-2006 Test methods for volume resistivity and surface resistivity of solid insulating materials

4. Arc resistance

Arc resistance (arc resistance) refers to the resistance of plastic materials by the high-voltage arc action caused by the deterioration of the ability to use the arc flame on the surface of the material caused by carbonization to the surface of the conductivity of the time required (s) that.

Test standard: GB/T 1411-2002 Dry solid insulating material resistance to high voltage small current arc discharge test.

Test Methods: GB/T 1743-2021 paint film gloss determination method

Author:

Ms. Tina

E-mail:

sales@honyplastic.com

Phone/WhatsApp:

+86 18680371609