Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
D1992-17 – Standard Test Method Technical Guide
📘 Overview and Scope of ASTM D1992
ASTM D1992 – 17 (Reapproved 2022), officially titled the Standard Guide for Testing Synthetic Plasticizers Used in Rubber, establishes a coordinated set of test methods for evaluating synthetic plasticizers in rubber compounding. Developed under the jurisdiction of ASTM Committee D11 on Rubber and Rubber-like Materials (Subcommittee D11.20 on Compounding Materials and Procedures), this guide serves as the primary reference for quality assurance in the industry.
The plasticizers covered by this standard are primarily esters, which may be either monomeric or polymeric in nature and are derived from various organic acids. They are specifically designed for use with polar elastomers, including Chloroprene Rubber (CR) and Nitrile Butadiene Rubber (NBR), to achieve three critical modifications: improved processing behavior, controlled hardness adjustments, and enhanced low temperature properties.
Section 3.2 of the standard emphasizes that while the listed test methods represent the most commonly specified parameters for quality control, they are not an exhaustive list. Depending on the specific application, additional test parameters may be necessary to fully characterize a given plasticizer.
⚠️ Regulatory Responsibility: As stated in Section 1.2, this standard does not address all safety concerns. Users are responsible for establishing appropriate safety, health, and environmental practices, and for determining the applicability of regulatory limitations prior to use of these materials.
⚙️ Core Test Methods and Material Properties
This guide consolidates a comprehensive suite of standard ASTM methods for testing synthetic plasticizers. The table below summarizes the primary properties, the specific test methods referenced, and their relevance to material performance.
| 🟦 Property | 📏 Referenced Method | 🎯 Significance in Rubber Compounding |
|---|---|---|
| Volatility | D2288 | Mass loss after 2 h and 24 h at 155 °C |
| Moisture Content | E203 | Karl Fischer titration for water content |
| Specific Gravity | D70, D891, D2111 | Batch consistency and purity checks |
| Flash & Fire Point | D92 (Cleveland Open Cup) | Safety classification for storage/handling |
| Color | D1209 (Pt-Co) / D1544 (Gardner) | Quality indicator and thermal stability |
| Refractive Index | D1218 | Material identification and purity |
| Saponification Value | D1962 | Ester content and type verification |
| Rheology | D2196 | Viscosity of non-Newtonian fluids |
💡 Volatility and Permanence: A plasticizer’s volatility is a key indicator of its permanence in a rubber compound. Per D2288, this is rigorously measured as mass loss at 155 °C. Measurements are typically taken after both a 2-hour and a 24-hour exposure to fully characterize thermal stability and evaporation rate.
Sampling is a critical step in obtaining reliable data. The standard guide directs users to Test Methods D1045 for detailed procedures on sampling plasticizers, whether sourced from tank cars or drums. Proper sampling ensures laboratory results accurately reflect the composition of the bulk material.
📊 Critical Testing Conditions from the Standard
Several tests within the guide require strictly defined conditions. The following table captures key environmental parameters specified by the standard.
| ⚡ Test Parameter | 📐 Specified Condition |
|---|---|
| Volatility Temperature | 155 °C |
| Volatility Duration | 2 hours & 24 hours |
| Moisture Analysis Method | Karl Fischer (E203) |
| Flash Point Apparatus | Cleveland Open Cup (D92) |
❓ Frequently Asked Questions
🔍 Which elastomers are the primary targets for synthetic plasticizers?
The guide specifies that these ester plasticizers are used with the more polar elastomers such as CR (Chloroprene Rubber) and NBR (Nitrile Butadiene Rubber) to improve processing, hardness, and low temperature properties.
💡 How is the volatility of a plasticizer determined according to this standard?
Volatility is determined according to Test Method D2288. The procedure measures the mass loss of the plasticizer after heating at 155 °C for periods of 2 hours and 24 hours.
⚡ What test method is specified for moisture content?
The moisture content of synthetic plasticizers should be determined using the Karl Fischer reagent procedure, as described in Test Method E203.
📌 Does this guide cover all necessary tests for every application?
No. Section 3.2 explicitly states that it is not implied that these test methods are the only ones of significance. These methods list the most commonly specified properties, but other parameters may be required for specific applications of the material.