The effect of difunctional acids on the performance properties of polyurethane coatings

Abstract

Hydroxyl-terminated polyesters are the most common polyols that are crosslinked through an isocyanate group. In this study, the polyester polyol resins were synthesized by using 1,4-cyclohexanedimethanol (1,4-CHDM) with the mixture of different diacids as 1,3-cyclohexanedicarboxylicacid (1,3-CHDA), 1,4-cyclohexanedicarboxylicacid (1,4-CHDA), isophthalic acid (IPA), adipic acid (AA), and azelaic acid (AZA). The solubility and viscosity of these polyester polyol resins were determined by using suitable solvent. All the polyester polyols were crosslinked with HDI isocyanurate and IPDI trimer to form polyurethane coating films. These films were evaluated for their mechanical, thermal, and chemical resistance properties. The studies on film characteristics reveal that the cycloaliphatic diacids afforded polyurethane with greater performance properties than that of aromatic and linear aliphatic diacids.

Migration of non intentionally added substances from adhesives by UPLC–Q‐TOF/MS and the role of EVOH to avoid migration in multilayer packaging materials

“…This compound could be an aromatic portion of polyester, OH terminated, used to obtain the final polyurethane. The use of aromatic isophthalic esters, gives mechanical behavior to the adhesive, increase the glass transition temperature, hardness and chemical resistance but on the contrary the phenyl ring adsorbs UV light limiting the photoxydative stability of the polyester …”

“…The use of aromatic isophthalic esters, gives mechanical behavior to the adhesive, increase the glass transition temperature, hardness and chemical resistance but on the contrary the phenyl ring adsorbs UV light limiting the photoxydative stability of the polyester. [7,26,31] Bis[2-(diethylamino)ethyl] 4,4'-[(2-methyl-1,3propanediyl)bis (oxycarbonylimino)] dibenzoate and Bis[2-(diethylamino)ethyl] 4,4'-[1,5-pentanediylbis(oxycarbonylimino)] dibenzoate were identified as potential migrants by screening the pure cured adhesive. They could be the degradation products of the polyurethane but also a by-product of the curing reaction.…”

“…Last generation of these adhesives has very low content of monomers so the risk of their migration is minimized. The choice between the different combinations of raw materials depends on the application field, type of packaged product, thermal treatment or mechanical characteristics . Different additives such as solvents, plasticizers, antioxidants, catalysts and flame retardants could be included into the adhesives’ formulation to provide special behavior and optimize their properties .…”

“…The choice between the different combinations of raw materials depends on the application field, type of packaged product, thermal treatment or mechanical characteristics. [5][6][7] Different additives such as solvents, plasticizers, antioxidants, catalysts and flame retardants could be included into the adhesives' formulation to provide special behavior and optimize their properties. [8] All these products added to the adhesives as well as residues of polymerization and also degradation products, by-products of curing reaction and of raw material production, could migrate into food through the polymer films.…”

Comparison of AdipicVersusRenewable Azelaic Acid Polyester Polyols as Building Blocks in Soft Thermoplastic Polyurethanes

“…Polyester polyols can also be produced from other dicarboxylic acids [12][13][14][15][16]. Recently, a significant effort has gone into development of biobased dicarboxylic acids.…”