Technical Report, Formulation of Polyurethane Foam, TDI-Free MDI Alternatives (New)

Description

  1. Abstract
    1. Toxic chemical free environment friendly polyurethane (PU)
    2. Possibility of improvement in properties using MDI in place of TDI
  2. Background
    1. Development of sustainable toluene isocyanate (TDI) free polyurethane because of environmental and government legislation on the toxic chemicals
    2. Can the properties of MDI based polyurethane be increased if it is used in place of TDI?
  3. Project Background
    1. Toluene diisocyanate (TDI) and polyol are two primary ingredients in manufacturing polyurethane foam (PU foam), but because of environmental regulations and legislation imposed by the government the utilization of TDI chemical is going to be restricted
  4. Requirements
    1. Suitable replacement of TDI and development of formulation accordingly
    2. How to enhance the properties of MDI-based PU foam with the use of certain additives
  5. Project Importance
    1. The usage of isocyanates in polyurethane synthesis is the most significant drawback of foam production, despite the fact that an inert product is formed at the end (PU foam)
    2. The phosgenation process (which is a reaction of phosgene with an amine salt at a temperature of around 200–250 degrees Celsius, giving the appropriate isocyanate) is used to produce isocyanates
    3. Asphyxia is caused by prolonged exposure to phosgene, which reacts with proteins in the pulmonary alveoli, disrupting the blood-air barrier and causing suffocation
    4. The European Community has categorized the two significant and frequently used monomers for polyurethane synthesis, TDI (toluene diisocyanate) and MDI (methylene diisocyanate), as CMR (carcinogenic, mutagen, reprotoxic) and in the category of "extremely hazardous" substances
    5. The eyes, skin, and respiratory tract become irritated after prolonged contact with TDI and MDI fumes
    6. Exposure to isocyanate fumes can also cause asthmatic respiration or difficulty breathing
    7. Growing worldwide awareness of the need to safeguard the environment and offer a healthier, cleaner, and greener world for future generations has increased the demand for environmentally friendly products
    8. This is where non-isocyanate-based polyurethane, which is non-toxic and environmentally friendly, comes into play
  6. Possible Replacement of Isocyanates (TDI and MDI)
    1. Different synthesizing routes of non-isocyanates polyurethane foam (NIPU) are as follow: the cyclic carbonate pathway (polyaddition), transurethanization (polycondensation), ring-opening polymerization, and rearrangement
    2. From these four possible routes to synthesize NIPU, the cyclic carbonate pathway (polyaddition) is considered the most feasible methodology
  7. Step 1: Synthesis of Cyclic Carbamates
    1. The most efficient way of this step is the insertion of CO2 into the epoxide group
  8. Step 2: Reaction to Give NIPU
    1. The reaction of synthesized cyclic carbonate oligomers with amines to give NIPU
    2. This is a simple reaction of addition after the ring opening procedure
  9. Comments on NIPU Process
    1. The NIPU synthesizing process is different from the conventional TDI/MDI and polyether/polyester polyols
    2. Just replacing a single chemical TDI/MDI, the chemistry to new process will be entirely different
    3. The NIPU is a different process that requires different catalysts and additives to get specific properties
    4. The reaction condition and processing time is different
    5. NIPU synthesizing process is a comparatively slow process as with the conventional commercial PU synthesis process because of the high reactivity of isocyanates
    6. NIPU process is under development process and has great potential to be a sustainable, healthier, and clean solution in near future
  10. Raw Material Providers
    1. The major companies that are involved in producing bio based chemical for synthesizing PU foam are BASF, DuPont, Myriant, Bio Amber, Covestro, General Mill Co, Allessa and Hankel Corporation
  11. Using MDI in Place of TDI Without Compromising on the Properties
    1. There is great possibility to get the required properties by using the MDI with the involvement of special additives
    2. Using this strategy with few changes in the process and addition of some chemical make the process good enough as TDI based PU foam
  12. Comments on MDI Replacement
    1. Easy to get the desired properties
    2. Fewer changes in process
    3. The low-density foam can be obtained with good tension properties as well
    4. MDI is less toxic as compared to TDI but still in categories of carcinogenic materials, because of that it is not a long-term solution
  13. Conclusion
    1. PU can be produced by using less toxic chemicals or the chemicals that are obtained from bio based resources
    2. The non-isocyanate polyurethane foam has great potential to replace the existing conventional PU market
    3. The hybrid non-isocyanate polyurethane market forecast to reach $8.12 million by 2025 growing at a CAGR of 10.3% during 2020-2025
  14. Project Routes
    1. Completely non-isocyanates polyurethane synthesizing process
    2. MDI based polyurethane with enhanced properties