Novel bio-based epoxy-polyurethane materials from modified vegetable oils – synthesis and characterization

Abstract

Abstract. Presented research shows the results of a study on the mechanical properties of materials obtained in the course of innovatory application of epoxidized vegetable oil in the synthesis of new bio-based epoxy resins, crosslinked with curing agents which are not typical for epoxy materials. The product was obtained via modern and pro-ecological modification of a well-known synthesis method of epoxies, namely the epoxy fusion process, then it was crosslinked using polyisocyanates of different structure: toluene-2,4-diisocyanate (TDI), hexamethylene diisocyanate (HDI) and 4,4′-methylene diphenyl diisocyanate (MDI). The obtained epoxy-polyurethane materials are characterized by various mechanical properties, which depend on the type of chosen isocyanate. Compositions based on HDI exhibit better mechanical characteristics than elastic polyurethane materials based on hydroxylated soybean oil. Materials cured with aromatic isocyanates MDI and TDI are characterized by higher mechanical resistance comparable with cast polyurethane based on petrochemical resources. Epoxy fusion product cured with toluene-2,4-diisocyanate in a presence of Dabco T9 appears to have the best mechanical properties among all tested compositions.

Blocked isocyanates as alternative curing agents for epoxy-polyurethane resins based on modified vegetable oils

“…During the preparation of above compositions, it was observed that the application of blocked isocyanates as hardeners for crossinking of polyaddition products ESBO_BPA or SMEG_EPR eliminates some of problems, which occurred for the duration of the curing using non-blocked polyisocyanates (Desmodur N75, Desmodur VL and Desmodur L75). These problems included (1) insufficient homogenization of the curing composition containing polyaddition product and hardener, due to the excessively increasing viscosity of the mixture and (2) extremely rapid curing process) [15]. All the compositions were transparent (Figure 3).…”

“…It is possible to crosslink products of the epoxy fusion process with, e.g. diisocyanates, obtaining novel epoxy-polyurethane materials characterized by the properties resulting from the choice of the curing method [13,15,16]. Facing the present ecological requirements, we obtained materials using polyisocyanates such as: hexamethylene diisocyanate (HDI), diphenylmethane-diiscoyanate (MDI) and tolene-diisocyanate (TDI) [15], and also blocked isocyanates (Desmocap 11, Desmocap 12, Desmodur BL1265, Desmodur BL 3272 MPA, Desmodur BL 3175 SN, Desmodur BL 4265 SN and Desmodur PL 340 BA/SN).…”

“…diisocyanates, obtaining novel epoxy-polyurethane materials characterized by the properties resulting from the choice of the curing method [13,15,16]. Facing the present ecological requirements, we obtained materials using polyisocyanates such as: hexamethylene diisocyanate (HDI), diphenylmethane-diiscoyanate (MDI) and tolene-diisocyanate (TDI) [15], and also blocked isocyanates (Desmocap 11, Desmocap 12, Desmodur BL1265, Desmodur BL 3272 MPA, Desmodur BL 3175 SN, Desmodur BL 4265 SN and Desmodur PL 340 BA/SN). One of the most important methods of the environmental protection is the replacement of toxic chemicals with compounds that have less harmful effects or reducing the toxicity of the compounds that are difficult to completely eliminate from the mass production and use.…”

Improve the Performance of Soy Protein-Based Adhesives by a Polyurethane Elastomer

“…Chemical and physical methods were applied to enhance water resistance of the SPIAs, including denaturation [5], cross-linking agents [6], synthetic resin [7], nano-material [8] and biomimetic modification [9]. Among those modifications, the most effective way is using cross-linking agents and synthetic resins, such as phenol formaldehyde resin [10], polyisocynates [11], polyamidoamine–epichlorohydrin resin [12] and epoxide [13]. The active functions of the cross-linker or synthetic resin react with the –NH 2 , –NH– and –COOH groups of the protein to generate a cross-linked structure, which improves the water resistance of the adhesive.…”

The Effects of TDI on Selected Properties of Ester Epoxy Alkyd Varnish

“…Điều này có thể được giải thích, khi tăng tỷ lệ chất đóng rắn thì mật độ đan lưới tăng làm cho mạch polyme hình thành cấu trúc không gian bền vững hơn làm cho polyme trở nên khó, thậm chí không thể hòa tan, cấu trúc không gian bền vững cũng làm cho dung môi rất khó khuyếch tán kéo dãn mạch polyme để làm tăng khối lượng và thể tích của polyme. Đối với các mẫu có dư chất đóng rắn M5 thì thành phần TDI cũng được tạo mạng không gian bởi kết với hơi ẩm, thành phần này rất bền vững với dung môi[12].Kết quả nghiên cứu trong Bảng 6 cho thấy, các mẫu vecny M3, M4, M5 có độ bền cao đối với dầu nhờn, axit HCl 5% và NaCl 5%, điều này cho thấy lựa chọn tỷ lệ chất đóng rắn TDI phù hợp thì màng vecny tạo ra có khả năng sử dụng để bảo vệ các chi tiết điện tử trong một số môi trường hóa chất.…”