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.

The molar mass distribution of biomass samples soluble in pure water or organic solvents (DMF, DMSO, and THF) is measured with size exclusion chromatography (SEC) with a refractive index detector (SEC-RID). The system is calibrated with polystyrene and dextran standards. A Pullulan standard is also available upon request. In the case of lignin samples, molar mass distribution is analyzed using SEC coupled with a Ultraviolet detector at 256 nm wavelength. The lignin is dissolved in a suitable solvent before analysis. The SEC system is calibrated with a polystyrene sulfonate standard. A borate buffer is used to set the pH for the eluent. The weight-average molecular weight and number-average molecular weight are reported. For absolute molecular weight, GPC system coupled with MALS detector can be used. The mobile phase for this system is THF. An additional cost applies to this method.

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 15 °C to 50 °C) and relative humidity (either 0% or 10% to 90%) upon requesting an offer. This measurement is suitable for materials with OTR values between 0.01 and 5000 cm3/(m2 * day).

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 typically 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 15 to 50°C) and the desired relative humidity (from 35% to 90%) when placing the order. This measurement is applicable for plastic films and sheeting materials with WVTR values between 0.005 and 2000 g/m²/day. If you wish to test finished packaging instead, check out the WVTR measurement for packages.

SEC-MALS (size exclusion chromatography with multi-angle light scattering) is a polymer analysis method that is used to characterize the molar masses and branching properties of polymers. This analysis gives information about a high molecular weight polymer's mass-average molar mass (Mw), numeric-average molar mass (Mn), polydispersity index (PDI), and information about branching.