Optical Properties
Polymer Refractive Index Table
Use this table to compare typical refractive index values for common polymers. For optical design, always record wavelength, temperature, sample form, and formulation state.
Quick Answer
| Polypropylene refractive index | Usually near nD 1.49 |
|---|---|
| Polyethylene refractive index | Often near nD 1.51, with crystallinity and density effects |
| PVC refractive index | Usually around nD 1.53-1.55 for many PVC references |
| Polystyrene refractive index | Usually near nD 1.59 |
| Report values with | Wavelength, temperature, grade, additives, and sample form |
Typical Refractive Index Values
| Polymer | Typical Refractive Index | Practical Notes |
|---|---|---|
| PTFE | ~1.35 | Low refractive index fluoropolymer baseline. |
| PDMS / silicone | ~1.40-1.41 | Often used where flexibility and low surface energy matter. |
| Polyethylene oxide (PEO) | ~1.46 | Moisture and crystallinity can change optical behavior. |
| Acrylic / PMMA | ~1.49 | Common transparent plastic for optical parts. |
| Polypropylene (PP) | ~1.49 | Useful low-cost baseline; crystallinity and orientation matter. |
| Polyethylene (PE) | ~1.51 | Density and crystallinity influence reported values. |
| Polyacrylonitrile (PAN) | ~1.51-1.52 | Relevant to fibers and precursor materials. |
| PVC | ~1.53-1.55 | Plasticizers, fillers, and stabilizers can shift values. |
| Polycarbonate (PC) | ~1.58-1.59 | High clarity and higher RI among common engineering plastics. |
| Polystyrene (PS) | ~1.59 | Aromatic structure gives a higher RI than many commodity plastics. |
Common Refractive-Index Questions
These direct comparisons provide a useful starting point; confirm the value with the exact grade and measurement conditions.
| Question | Fast answer | Further reading |
|---|---|---|
| What is the refractive index of PVC? | about nD 1.53-1.55 | PVC refractive index |
| What is the refractive index of PP? | usually near nD 1.49 | PP refractive index |
| What is the refractive index of PE? | often near nD 1.51 | PE refractive index |
| What is the refractive index of common plastics? | common plastics are roughly nD 1.35-1.59 | Plastic refractive index |
| How should refractive index be reported? | RI must be reported with wavelength and temperature | Refractive index and methods |
Measurement Notes
Most quick references use a sodium D-line style value, commonly written as nD. That is only comparable when the wavelength, temperature, and sample condition match. Thin films, molded plaques, filled compounds, and solutions can all produce different values.
- Use ellipsometry, refractometry, or prism-coupling methods appropriate to the sample form.
- For transparent optical parts, pair refractive index with haze, transmission, yellowness, and thermal aging data.
- For formulation work, measure the final compound, not only the neat base polymer.
Research Backing
The refractive-index guide now links into a DOI-backed research corpus instead of standing alone as a thin lookup table. Use these clusters when checking wavelength, film form, optical constants, and method-dependent values.
Optical and refractive-index papers
181 papers covering refractive index, optical polymers, ellipsometry, dielectric behavior, transparent systems, and photonic materials.
Thermal and morphology context
516 papers for crystallinity, thermal history, and morphology effects that can shift optical measurements.
Polymer chemistry principles
Use polarizability, aromaticity, crystallinity, side groups, and morphology to interpret refractive-index differences.
Complete bibliography
All 1,000 public polymer research records with DOI/open-access links.
Related Refractive Index Lookups
Polypropylene refractive index
PP values with crystallinity and grade notes.
Refractive index of polystyrene
PS values and high-RI context.
Refractive index of polyethylene
PE values and density-dependent context.