Two homopolyesters and a series of novel random copolyesters were synthesized from two bio-based diacid esters, dimethyl 2,5-furandicarboxylate, a well-known renewable monomer, and dimethyl 2,2'-bifuran-5,5'-dicarboxylate, a more uncommon diacid based on biochemical furfural. Compared to homopolyesters poly(butylene furanoate) (PBF) and poly(butylene bifuranoate) (PBBf), their random copolyesters differed dramatically in that their melting temperatures were either lowered significantly or they showed no crystallinity at all. However, the thermal stabilities of the homopolyesters and the copolyesters were comparable. Based on tensile tests from amorphous film specimens, it was concluded that the elastic moduli, tensile strengths, and elongation at break values for all copolyesters were similar as well, irrespective of the furan:bifuran molar ratio. Tensile moduli of approximately 2 GPa and tensile strengths up to 66 MPa were observed for amorphous film specimens prepared from the copolyesters. However, copolymerizing bifuran units into PBF allowed the glass transition temperature to be increased by increasing the amount of bifuran units. Besides enhancing the glass transition temperatures, the bifuran units also conferred the copolyesters with significant UV absorbance. This combined with the highly amorphous nature of the copolyesters allowed them to be melt-pressed into highly transparent films with very low ultraviolet light transmission. It was also found that furan-bifuran copolyesters could be as effective, or better, oxygen barrier materials as neat PBF or PBBf, which themselves were found superior to common barrier polyesters such as PET.

中文翻译：

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利用糠醛基双呋喃二酯作为高性能生物塑料的单体和共聚单体：聚呋喃丁酸酯，聚呋喃丁酸酯及其共聚酯的性能。

由两种生物基二酸酯，一种众所周知的可再生单体2,5-呋喃二甲酸二甲酯和一种2,2'-bifuran-5,5'-二羧酸二甲酯合成了两种均聚酯和一系列新型无规共聚酯。基于生化糠醛的不常见的二酸。与均聚酯聚呋喃丁酸丁二醇酯（PBF）和聚呋喃丁二酸丁二酯（PBBf）相比，它们的无规共聚酯差异显着，因为它们的熔融温度显着降低或完全没有结晶性。然而，均聚酯和共聚酯的热稳定性是可比较的。根据无定形薄膜样品的拉伸试验得出的结论是，与呋喃无关，所有共聚酯的弹性模量，拉伸强度和断裂伸长率值也相似：双呋喃摩尔比。对于由共聚酯制备的非晶膜样品，观察到约2 GPa的拉伸模量和高达66 MPa的拉伸强度。然而，将双呋喃单元共聚成PBF允许通过增加双呋喃单元的量来提高玻璃化转变温度。除了提高玻璃化转变温度外，双呋喃单元还赋予共聚酯以明显的紫外线吸收。这与共聚酯的高度无定形性质相结合，使它们可以熔融压制成具有非常低的紫外线透射率的高度透明的薄膜。还发现呋喃-双呋喃共聚酯可以与纯PBF或PBBf一样有效或更佳的阻氧材料，而纯PBF或PBBf本身被发现优于普通的阻隔聚酯，例如PET。对于由共聚酯制备的非晶膜样品，观察到约2 GPa的拉伸模量和高达66 MPa的拉伸强度。然而，将双呋喃单元共聚成PBF允许通过增加双呋喃单元的量来提高玻璃化转变温度。除了提高玻璃化转变温度外，双呋喃单元还赋予共聚酯以明显的紫外线吸收。这与共聚酯的高度无定形性质相结合，使它们可以熔融压制成具有非常低的紫外线透射率的高度透明的薄膜。还发现呋喃-双呋喃共聚酯可以与纯PBF或PBBf一样有效或更佳的阻氧材料，而纯PBF或PBBf本身被发现优于普通的阻隔聚酯，例如PET。对于由共聚酯制备的非晶膜样品，观察到约2 GPa的拉伸模量和高达66 MPa的拉伸强度。然而，将双呋喃单元共聚成PBF允许通过增加双呋喃单元的量来提高玻璃化转变温度。除了提高玻璃化转变温度外，双呋喃单元还赋予共聚酯以明显的紫外线吸收。这与共聚酯的高度无定形性质相结合，使它们可以熔融压制成具有非常低的紫外线透射率的高度透明的薄膜。还发现呋喃-双呋喃共聚酯可以与纯PBF或PBBf一样有效或更佳的阻氧材料，而纯PBF或PBBf本身被发现优于普通的阻隔聚酯，例如PET。