25 августа, 2015 
Malyar As mentioned previously, neat pMDI does not have gap filling capability for wood bonding because of its low viscosity and propensity for deep penetration. Consequently, neat pMDI is not used for applications such as plywood, laminated veneer lumber, etc. However, gap filling properties may be achieved by modifying pMDI with a wide variety of difunctional or polyfunctional polyols. Viscosity and NCO content are easily tailored to meet many application requirements.
2. PF/pMDI Hybrid Adhesives
There has been some interest in combining aqueous PF or UF resins directly with pMDI resins [52-54]. The properties of the hybrid depend upon the blend ratio and the method of mixing. The resulting hybrids can be formulated with a wide range of viscosities, appropriate for lamination or spray applications (see Chapter 26, page 565). Presently, it is not clear if these hybrids will yield widespread, economically viable technologies although commercialization has already taken place [53,55].
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