2013 Volume 34 Issue 3 Pages 135-143
In order to investigate molecular designs on lignophenols (LP) for network type macromolecules using benzyl structures which are one of the most reactive structures in native lignin, p-cresol grafting on LP with benzyl structures through the phase-separation system (PSS) were carried out. Several LP were allowed to react with formaldehyde, glyoxal (GO) and glutalaldehyde (GA) in 0.1M NaOH solutions at 60℃ for 3h. Both Hinoki cypress (Chamaecyparis obtusa)-LP (p-cresol type, HCLC) and Hinoki cypress-LP (catechol type, HCLCat) were synthesized through PSS (process-II) directly from softwood extractive-free wood meal (60 mesh passed) of Hinoki cypress, respectively. Both hydroxymethylated HCLC (HCLC-HM) and HCLCat-HM were obtained with 94.3％ and 96.0％ yields, respectively. In addition, HCLC-GO and HCLC-GA showed 88.9％ and 101.0％ yields, respectively. These derivatives were absorbed on beaten and dried kraft pulp with Canadian freeness index 100 (3.1 m3g-1 of BET surface area) as vanishing reaction supports (VRS) in order to keep both surfaces and conditions of PSS reactions. Through PSS with p-cresol (pC) for these derivatives using the VRS, HCLC-HMpC, HCLC-GO-pC, HCLC-GA-pC and HCLCat-HM-pC were obtained with 77.8％, 81.5％, 72.1％ and 77.5％ yields. For these second derivatives, analyses on both structures and properties using FT－IR, 1H-NMR, TMA and TGA were carried out in order to estimate designs for network macromolecules. The results of these analyses demonstrated that p-cresol moiety was highly introduced to both HCLC-HM-pC and HCLCat-HM-pC. On the contrary, both HCLC-GO and HCLCGA showed only few proofs of network type structures, but some reversible protections on hydroxyl groups with keeping LP structures were observed. As HCLCat-HM-pC showed the largest content of p-cresol by 1H-NMR, the combination of both Synopsis
