Inclusion Complexes Between Polytetrahydrofuran‐b‐Amylose Block Copolymers and Polytetrahydrofuran Chains

Abstract

Amylose inclusion complexes are prepared by complexation of synthetic amylose having a covalently attached PTHF block (PTHF-b-amylose) with guest polytetrahydrofuran of molecular weights of 650 and 1000 g · mol(-1) (PTHF650 and PTHF1000). Differential Scanning Calorimetry (DSC) analysis of the products shows a characteristic melting peak of the complexes at 140 °C. Compared to PTHF650, the PTHF1000 displays lower complexing ability with PTHF-b-amylose which is indicated by visible amylose retrogradation. The possible structures of the resulting products are estimated from Thermo Gravimetric Analysis (TGA) which reveals differences between PTHF-b-amylose and the corresponding complexes. In addition, X-Ray Diffraction (XRD) analysis demonstrates that the resulting structures of the complexes consist of 6-fold V-amylose helices. The results are confirmed further with Small Angle X-Ray Scattering (SAXS) diffractions which show that formation of inclusion complexes increases the crystalline size and regularity of the complex. There is a strong indication that the covalently attached PTHF block also induces the formation of V-amylose by residing in between the amylose blocks. In this case, the resulting structure of the complex is likely affected by both the complexation between amylose block and the added PTHF and by the in situ self-assembly of the block copolymers.

Self-assembly of maltoheptaose-b-PMMA block copolymer systems: 10 nm Resolution in thin film and bulk states

“…Poly-/oligosaccharides-based "green" hybrid BCPs are one of the best examples of such efforts (Haddleton & Ohno, 2000;Bosker, 2003;Aissou et al, 2011;Cushen et al, 2012;Otsuka, Tallegas, et al, 2013Isono, Otsuka, Suemasa, et al, 2013;Isono, Otsuka, Kondo, et al, 2013;Rachmawati, Woortman, Kumar, & Loos, 2015;Tanaka, Sasayama, Yamamoto, Kimura, & Kadokawa, 2015;Zepon et al, 2015). Indeed, the poly-/oligosaccharides-based BCPs can offer further advantages than environmental friendliness thanks to their unique characteristics.…”

Synthesis of Telechelic and Three-Arm Polytetrahydrofuran-block-amylose

“…HMTA was used as terminating agent as it results in a good primary amine functionality to the resulted PTHF as described previously. [ 19,28 ] Trifl ic anhydride was chosen as it can initiate the polymerization of THF which results active sites at both ends of the opened THF. [ 37 ] Afterward, the resulted difunctional THFcontaining initiator can initiate the propagation of the CROP of THF, as shown in Scheme 3 .…”

“…In addition, NaBH 3 CN was used in fi vefold excess compared to maltoheptaose. [ 19 ] As shown in Table 2 , the yield of the product from educt PTHF1100 is low (5%-12%), greatly infl uenced by the purifi cation technique. Water was used to precipitate the product and to wash away unreacted maltoheptaose.…”

“…Besides being a biodegradable polymer, the amylose block in amylose-b -PTHF-b-amylose is presumed to be able to host guest molecules in a similar way to PTHF-b -amylose. [ 19 ] One of the possible inclusion ways between amylose-b -PTHF-b -amylose and guest PTHF is depicted in Figure 1 . The amylose as the A block is modifi ed into an amylose-PTHF complex so that the resulting structure can be written as an ABA triblock copolymer in the form of [amylose−PTHF complex]-b -PTHF-b -[amylose−PTHF complex].…”

Amylose engineering: phosphorylase‐catalyzed polymerization of functional saccharide primers for glycobiomaterials

“…The gelation was probably caused by the formation of inclusion complexes between the branched polymers. A similar approach was used to show inclusion complex formation by an amylose–PTHF conjugate …”