Solvent-free synthesis of monomers is one among the most promising ways to develop greener polymers that are both environmentally and economically acceptable, but it was described as one of the “grand challenges” facing chemists. As a contribution towards sustainable bioplastics development which has attracted great attention in materials science research, a truly efficient, practical, and more environmentally friendly solvent-free synthetic route was successfully applied herein to prepare three new fully biobased diol monomers derived from vanillic acid and aliphatic diols (ethylene glycol, 1,3-propanediol and 1,4-butanediol). Their chemical structures were confirmed in detail by ¹H, ¹³C NMR and FTIR spectroscopies while their thermal properties were investigated by DSC and TGA. Results showed high melting points in the 121.8–142.3 °C range and no significant weight loss (T_{d, 5%}) up to 243, 312 and 284 °C respectively for diols with 2, 3, and 4 methylene units. To prove their suitability in polymerization, melt polycondensation of prepared diols with three diacyl chlorides and also with dimethyl 2,5-furandicarboxylate were successfully carried out under catalyst-free conditions and using tetrabutyl titanate (TBT), respectively. The chemical structures of the novel series of polyesters were confirmed in detail by NMR and FTIR spectroscopies. The latter showed satisfactory intrinsic viscosity values in the 0.25–0.30 dL/g range and a wholly amorphous nature. All materials revealed high thermal stability with onset degradation temperatures T_{d, 5%} ranging from 314 to 373 °C and a wide glass transition temperature (T_g) range oscillating from -2.8 to 69.5 °C. The innovative approach proposed herein for the first time, which involves the synthesis of sustainable monomers under solvent-free conditions, is fully aligned with one of the main principles of green chemistry.

单体的无溶剂合成是开发在环境和经济上都可以接受的绿色聚合物的最有前途的方法之一，但它被描述为化学家面临的“巨大挑战”之一。作为对可持续生物塑料发展的贡献（已在材料科学研究中引起广泛关注），本文成功地采用了真正有效，实用，更环保的无溶剂合成路线，以制备从香草酸和脂族化合物衍生的三种新型全生物基二醇单体二醇（乙二醇，1，3-丙二醇和1，4-丁二醇）。¹ H，¹³详细证实了它们的化学结构通过DSC和TGA研究了13 C NMR和FTIR的热性质。结果显示熔点在121.8–142.3°C范围内，并且没有明显的重量损失（T _d，5％）分别将具有2、3和4个亚甲基单元的二醇的温度分别升高到243、312和284°C。为了证明其在聚合中的适用性，分别在无催化剂的条件下和分别使用钛酸四丁酯（TBT）分别成功地将制得的二醇与三种二酰氯以及2,5-呋喃二甲酸二甲酯进行熔融缩聚反应。新型聚酯系列的化学结构通过NMR和FTIR光谱学得到了详细证实。后者在0.25–0.30 dL / g的范围内显示出令人满意的特性粘度值，并且具有完全无定形的性质。所有材料均显示出高的热稳定性，起始降解温度T _d为314至373°C，变化范围为_5％，玻璃化转变温度（T _g）的范围是-2.8至69.5°C。本文首次提出的创新方法涉及在无溶剂条件下合成可持续单体，这与绿色化学的主要原理之一完全吻合。