Core expertise
Multi-detector size exclusion chromatography for molecular weight, distribution, branching and solution behaviour — with scientific interpretation of what the data means for your material.
Scope
Molecular weight governs mechanical performance, processability, degradation behaviour and regulatory comparability. We select the column set, solvent system and detector configuration appropriate to your polymer, then interpret the distribution in the context of your product.
Compare processed, sterilized, aged or field-returned material against a control or reference lot.
Conformation plots from light scattering and viscometry indicate long-chain branching and structural differences.
Distribution overlays and dispersity comparisons support lot-to-lot and supplier-to-supplier assessment.
Light scattering provides molecular weight independent of column calibration standards.
Measurements
Number-average molecular weight
Sensitive to low molecular weight fractions and oligomers.
Weight-average molecular weight
Correlates with melt behaviour and mechanical performance.
z-average molecular weight
Emphasizes the high molecular weight tail.
Dispersity (Mw/Mn)
Breadth of the molecular weight distribution.
Molecular weight distribution
Full distribution curve, including shoulders and tails.
Intrinsic viscosity
Solution behaviour and hydrodynamic volume via viscometry.
Radius of gyration
Molecular size in solution from light scattering.
Branching index
Contraction factor indicating long-chain branching.
Configurations
Configuration
Detectors
Best used for
Key outputs
Conventional GPC/SEC
RI (± UV)
Routine comparison against calibration standards
Relative Mn, Mw, Mz, Đ, MWD
Light scattering (MALS)
RI + MALS
Absolute molecular weight without column calibration
Absolute Mw, Rg, aggregation
Viscometry
RI + viscometer
Solution behaviour and universal calibration
[η], Mark–Houwink parameters
Triple detection
RI + MALS + viscometer
Complex, branched or novel polymers
Absolute M, Rg, [η], branching (g, g′)
UV-selective
RI + UV/PDA
Copolymers and chromophore-containing species
Composition trends across the distribution
Column set, solvent, temperature and detector combination are selected per material. High-temperature and aqueous configurations are assessed case by case.
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Approach
Method selection
Solvent, column chemistry, temperature and calibration approach chosen for the polymer and the question.
Method development
Where no suitable method exists, we develop and document one, including solubility and recovery assessment.
Comparative studies
Structured control-versus-test designs for processing, sterilization, ageing and supplier changes.
Interpretation
Reporting that states what the distribution indicates about the material, not only the numbers.
Examples
Sterilization effect on a resorbable device polymer
GPC/SEC before and after irradiation to quantify chain scission, supported by DSC for thermal change.
Incoming resin qualification
Distribution overlays across supplier lots to define an acceptable molecular weight window.
Novel branched polymer characterization
Triple detection with conformation plots to describe branching relative to a linear reference.
Samples
Typically 20–100 mg of solid polymer, or 5–10 mL of solution, per analysis.
Provide known solvents, solubility observations and any additives or fillers present.
Include a control or reference lot wherever a comparison is the objective.
Safety data sheets are required before shipment. Specific requirements are confirmed during project scoping.
Quality
Accreditation applies to specific methods within a defined scope rather than to all work performed. [Verified accreditation details] — applicable accredited methods are confirmed during project scoping.
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