Polyester/lignosulfonate blends with enhanced properties

Abstract

The compatibility of poly(ethylene terephthalate) and its copolymer containing isophthalate units with epoxy‐modified lignin has been studied. The following methods have been used: DSC, thermogravimetry, IR spectroscopy, contact angle measurements and dielectric properties determination. The optimum compatibility ratios and the necessity of a partial crosslinking with 4,4′‐diaminodiphenylmethane to obtain a stable morphology have been established.

Chemistry of lignin-based materials

“…169,170 Because lignin contains hydroxyl groups, lignin can behave as the polyol in the polyester synthesis, and also lignin hydroxyl groups can be modifi ed to other functionalities such as carboxylic acid, 171,172 acyl groups, 114,172 epoxy groups 173 and terminal hydroxyl groups. 9,10,12,13,15,16,93,[173][174][175][176][177][178][179] Polyesters are popular components to produce lignin polymeric composites. Lignin may be used as a fi ller to reduce production cost, as a reinforcement agent and a biodegradable component.…”

“…Commonly used commercial polymer, PET, was blended with lignin with various methods including a lignin portion of generally up to 20% by weight. 93,173,174 Most reports include thermal property characterization -such as differential scanning calorimetry and thermogravimetric analysis -and morphology studies using SEM images. Epoxy-modifi ed lignin, 180 which is functionalized lignin by epichlorohydrin in strong alkaline media, was blended with PET at 100°C followed by pressing at 220°C.…”

“…Epoxy-modifi ed lignin, 180 which is functionalized lignin by epichlorohydrin in strong alkaline media, was blended with PET at 100°C followed by pressing at 220°C. 173 The lignin-PET blend showed improved thermal properties with good compatibility according to the SEM morphology study. 173 In a different report, hydrolytic lignin was blended with PET in a single-screw thermal extruder to produce lignin-PET blend.…”

Competitive Interactions in Aromatic Polymer/Lignosulfonate Blends

“…A considerable number of papers have been published on the blends of lignin with a wide range of polymers including proteins [10][11][12], starch [13][14][15], polyolefins [16][17][18][19][20][21][22][23][24][25][26], vinyl polymers 4 [18,19,21,[27][28][29][30][31][32][33][34][35] and polyesters [19,21,22,[36][37][38][39][40][41][42][43]. The chemical modification of lignin [10,14,16,[20][21][22]27,29,36,40,…”

“…The chemical modification of lignin [10,14,16,[20][21][22]27,29,36,40,41] and coupling [16,17,20,24,25,27,28] is often used to achieve better properties in polymer/lignin blends. Lignin may also be applied as a reactive component in epoxy [44,45] and phenol formaldehyde resins [46,47], as well as in polyurethanes [48][49][50].…”