Date of Award
Spring 5-15-2024
Document Type
Thesis
Degree Name
Master of Science (MS)
Department
Chemistry
First Advisor
Dr. Ram K. Gupta
Second Advisor
Dr. Siam S. Khamis
Third Advisor
Dr. John Franklin
Abstract
One of the considerable forms of polyurethanes (PUs) with significant potential for insulation and energy efficiency is rigid foam, which is mostly utilized in the construction, refrigeration, and automobile sectors. However, RPUFs are quite combustible and may ignite and spread flames rapidly. As an economical, environmentally friendly, and effective alternative to non-halogenated flame retardants (FRs), nitrogen-based chemical substances are used to reduce the flammability of PU foam. It is demonstrated by research that the ideal choice for incorporating flame-retardant compounds with rigid polyurethane foams is based on melamine derivatives, which majorly contain nitrogen in their structure. Adding melamine and its derivatives to rigid foam enhances its thermal stability and efficiency to prevent fire spread. This thesis aims to incorporate environmentally friendly components into the castor oil polyol, which is utilized to make rigid polyurethane foams. In addition to these, castor oil is inedible and has many functionalized chemical groups that can be used to create polyurethane even without modification. The limited load-bearing capability and lack of thermal stability of RPUFs derived from castor oil restrict their industrial application. These limitations were addressed in two ways: (i) by adding additional hydroxyl groups using standard chemistry methods - the crosslinking density was increased; and (ii) by adding three environmentally friendly FRs - the thermal stability of polyurethane foams was improved. Based on test conclusions, 210 kPa of compression strength, 95% closed cell content, and an apparent density of 37.50 kg/m3 were observed in the manufactured castor oil-based polyurethane foams without FRs. Even after the addition of FRs, the structural integrity of the foam remains the same indicating the better compatibility of FRs and the castor oil-based PU matrix. As the flame-retardant proportion increased, it also raised flame-retardancy and thermal stability. While rigid polyurethane foams based on castor oil and FRs based on nitrogen showed good mechanical properties and relatively poor thermal stabilities, rigid polyurethane foams based on castor oil and FRs based on phosphorus and nitrogen demonstrated good thermal qualities but relatively poor mechanical characteristics. Nitrogen and phosphorous-based rigid polyurethane foams containing castor oil perform better flame retardancy. This work illustrated that FRs based on nitrogen and phosphorus can lower the flammability of polyurethanes derived from castor oil without significantly altering their physical properties.
Recommended Citation
Chaudhary, Niyati, "HIGHLY FLAME-RETARDANT BIO-BASED FOAMS USING CASTOR OIL AND MELAMINE-BASED INTUMESCENT FLAME RETARDANTS" (2024). Electronic Theses & Dissertations. 517.
https://digitalcommons.pittstate.edu/etd/517
