Preparation of novel, liquid, solvent‐free, polyolefin‐based adhesives

Abstract

An innovative procedure for functionalization of polyolefins was developed. It was found that synthesized polyolefins end-capped with trimethoxysilane (silylated polyolefins) are new polyolefin-based adhesives. To prepare the mentioned materials,1-octene as a higher α-olefin was cooligomerized with two linear, nonconjugated dienes (ie, 1,5-hexadiene and 1,7-octadiene) by using metallocene catalyst system, Cp 2 HfCl 2 /MAO, at room temperature. Then, amine-terminated trimethoxysilane (3-aminopropyltrimethoxysilane) was reacted with unsaturated bonds of synthesized cooligomers in the presence of palladium(II) acetate. Embedding of the dienes on 1-octene oligomeric chains was explored by Fourier transform infrared (FTIR), 1 H, and 13 C-NMR spectroscopy. On the basis of the results, 1,5-hexadiene showed both 1-butene branch and five-member ring. On the other hand, 1,7-octadiene was incorporated by 1,2-addition, forming both 1-hexene branch and seven-member ring in the cooligomer backbone. Mole percentage of C C and cyclic moieties reached to a value of 28.54, 18.59% mol in 1-octene/1,5-hexadiene, and 38.04, 6.71% mol in 1-octene/1,7-octadiene cooligomers, respectively. Reaction of synthesized cooligomers with 3-aminopropyltrimethoxysilane was confirmed by FTIR spectroscopy, which yielded targeted adhesives. To study the adhesion properties, resulting adhesives were applied to different substrates. Obtained results demonstrated that tensile shear strength of synthesized adhesives to polar substrates was 2.21% to 2.84% more than nonpolar substrates. Among studied systems, the best performance was achieved by1-octene/1,7-octadiene-based adhesive and Al substrate with tensile shear strength of 1.45 N/mm 2 .

Single‐phase photo‐cross‐linkable adhesive synthesized from methacrylic acid‐grafted 1‐decene/9‐decene‐1‐ol cooligomer

“…[38] Furthermore, the high bond strength of synthesized adhesives on Al surface can also be explained by the presence of functional groups, which can form covalent bonds with Al surface, since it is always covered by a natural oxide/hydroxide surface layer. [17] On the other hand, among the utilized polymeric substrates, prepared adhesive shows low adhesion toward PS one. This phenomenon can be due to the lack of functional groups on PS substrate.…”

“…This behavior has already been reported by other authors, too. [17,37] According to the data collected in Table 1, average molecular weight (M n ) is determined as 480 and 715 g/mol, for oligomer and cooligomer samples, respectively (see Figure 3). Surprisingly, insertion of 9-decene-1-ol as a comonomer on oligomer chains led to shifting of M n to higher values.…”

“…[39] Similar trend has been observed in our previous article with adhesives based on oligo-1octene end-capped with trimethoxysilane. [17] Generally, adhesion is a critical design characteristic of many commercial adhesives. In order to obtain better adhesion properties, the adhesive must be adhered to interface by chemical bonds.…”

“…[3,4] In this line, a number of methods for copolymerizing polar vinyl monomers with nonpolar olefin monomers have been studied. [5][6][7][8][9][10][11][12][13] Aforementioned copolymers/cooligomers have applications in industries such as clean diesel fuel alkanes, [14] octane boosters and new monomers, [15] adhesives, [16,17] compatilizers [18,19] synthetic lubricants, [20][21][22][23] additives for fuels [20] or in the paper, and leather industries. [24,25] Furthermore, hydroxy-terminated oligopropenes are useful as initiators in caprolactone polymerization to form poly(propene-bcaprolactone) block copolymers.…”

“…In our last publication, we reported a new method for functionalization of polyolefins, in which oligo-1-octene end-capped with trimethoxysilane (silylatedpolyolefins) was produced as a material, which was applicable as an extraordinary polyolefin-based adhesive. [17] Many works have been done to insert functional groups within polymer chains to make them capable in the adhesive applications. However, up to now, no investigation that reports functionalization of higher α-olefins oligomers to use them in the photo-curable adhesive applications has been reported yet.…”