Refractive index of plastics

X-Ray Reflectometry (XRR) analysis is used to measure the density (g/cm3), thickness (nm), and roughness (nm) of thin films. The method is applicable to the characterization of single- or multilayered thin films, as it provides information on the thickness and density of individual layers of the sample material as well as the roughness of the interphases. Greatest accuracy for XRR thickness measurements is generally achieved for samples containing 1-150 nm thick surface layers with under 5 nm RMS roughness. Thicker films and coatings with rougher surfaces can also be characterized, but the accuracy of thickness determination decreases as the thickness and roughness of the film or film stack increase. >150 mm wafers are typically cut to fit the sample holder. Please let us know if you need testing for larger wafers that cannot be cut into pieces. The available temperature range for XRR measurements is 25-1100 °C, and crystallinity can be studied as a function of temperature. The measurements can be performed under a normal atmosphere, inert gas, or vacuum. Measurements are typically performed using one of the following instruments: Rigaku SmartLab, Panalytical X'Pert Pro MRD, Bruker D8 Discover. Please let us know if you have a preference for a specific instrument.

This test is designed to measure the oxygen transmission rate of finished packages, including cups, bottles, trays, and containers. Two replica measurements are included in the displayed price. Temperature can be adjusted from 15 to 55 °C, and relative humidity can be either 0% or between 5 and 90% RH. This test is not suitable for films. Please see the oxygen transmission rate (OTR) of films and sheeting if you need testing for film samples. Please specify the sample dimensions and testing conditions upon ordering.

Determination of the water vapor transmission rate (WVTR) of ultra-high barrier materials. The method can also be used to test moderate barrier materials at high-temperature conditions. Please disclose the desired temperature (from 10 to 85 °C) and the desired relative humidity (from 60% to 100%) when placing the order. This measurement is applicable for films and sheeting materials with WVTR values between 1x10-6 and 10 g/m2/day. If you wish to test finished packaging instead, check out the WVTR measurement for packages. The price of the test consists of a flat rate cost per sample plus one day measurement time. Please contact our experts for an offer.

Determination of the oxygen transmission rate of plastic films and sheet-like materials. The test is performed on two parallel samples simultaneously. Measurement conditions (temperature and relative humidity) can be chosen according to the intended use of the material. Oxygen permeability is typically measured at 23 °C and 0% relative humidity as per standard ASTM D3985. In moist conditions, for example at 38 °C and 90% relative humidity, standard ASTM F1927 is used. Please disclose the desired temperature (from 10 °C to 38 °C) and relative humidity (either 0% or from 20% to 90%) upon ordering. This measurement is suitable for plastic films with OTR values between 0.05 to 20 000 cm³/(m² * day).

Gel permeation chromatography (GPC), a.k.a. size exclusion chromatography (SEC), of polymers using a refractive index (RI) detector. This technique will measure the molecular weight distribution of polymer samples in a graphical format, the dispersity, Đ, and determine the molecular weight averages, Mn, Mw, Mz, relative to an existing standard. Please note that the numerical values determined for molecular weight by the RI method are not absolute. GPC/SEC-RI is most commonly used to analyze the graphical distribution or dispersity of a polymer. If you need an absolute determination of your sample's true molecular weight, please see our GPC/SEC-MALS method. Samples must be soluble or capable of being analyzed in solution at room temperature. The type of polymer and the necessary solvent will affect the cost of the measurement. Please contact our experts for a tailored quote.

The gravimetric dish method can be used to determine the water vapor transmission rate (WVTR) of materials that have a high water vapor permeability. This method is intended for plastic films or sheeting materials with a water transmission rate of over 1 g/m²/day. The maximum sample thickness is 3 mm. In the test, a water-absorbent material is placed in a metal cup that is covered by the studied material, which is sealed to the cup with wax. The test sample is placed in a conditioned cabinet and its mass is measured. From this, the WVTR value can be calculated. The method is not applicable for materials that are damaged by hot wax or shrink under the used test conditions.

In this analysis, the density of plastics and polymers is determined by the immersion method specified in part A of the ISO 1183-1 standard. The method is suitable for plastic granulates and for products and materials delivered as sheets that can be cut into the right shape in the lab. If the sample is delivered as granulates, the test objects are prepared in the lab by injection molding. The price includes sample preparation.

Determination of the nitrogen or helium transmission rate of plastic films and sheet-like materials with the differential pressure method. Testing is performed on three parallel samples. Measurement conditions (temperature and relative humidity) can be chosen according to the intended use of the material. Please disclose the desired temperature (from 5 °C to 95 °C) and relative humidity (either 0% or from 10% to 90%) upon ordering. Oxygen (O2) and carbon dioxide (CO2) transmission rates can also be determined with the manometric method upon request, but the following, more cost-efficient measurements are used more often: OTR of films and sheeting, CO2 transmission rate of films and sheeting.

This measurement determines the transmission rate of carbon dioxide (CO2) through a single or multi-layered plastic film or sheeting with an infrared detector. The measurement is performed with two parallel specimens. The testing temperature is 23°C, and the relative humidity is 0%.

Determination of the water vapor transmission rate (WVTR) according to the ASTM F1249 standard. WVTR describes the amount of water vapor that passes through a material over a set period. It is an important quality indicator in food and cosmetics packaging, as an effective moisture barrier is critical to keeping products fresh and preventing spoilage. In this WVTR test, two samples per material are measured simultaneously to ensure the reliability of the measurement. The results are expressed as g/m²/day. Please disclose the desired temperature (from 18 to 40°C) and the desired relative humidity (from 20% to 100%) when placing the order. This measurement is applicable for plastic films and sheeting materials with WVTR values between 0.005 and 2400 g/m²/day. If you wish to test finished packaging instead, check out the WVTR measurement for packages.