Biodegradable High-Molecular-Weight Poly(pentylene adipate-co-terephthalate): Synthesis, Thermo-Mechanical Properties, Microstructures, and Biodegradation

Abstract

Poly­(pentylene adipate-co-terephthalate) (PPAT) is a promising biobased and biodegradable polymer that can replace polyethylene in flexible packaging films where biodegradability is desired. High-molecular-weight (100K–145 KDa) aliphatic–aromatic polyester PPAT was successfully synthesized, and the effects of reaction conditions on molecular weight were reported. PPAT polyesters were characterized for polymer compositions, number-average unit length, thermal transitions, and rheological properties. PPAT compression-molded films were characterized for crystallinity and tensile properties to correlate micro- and macroproperties. PPAT compression-molded films exhibited up to a 76% higher tensile modulus than compression-molded films from poly­(butylene adipate-co-terephthalate) (PBAT), making PPAT films potentially comparable with compression-molded films from linear low-density polyethylene (LLDPE). PPAT is biodegradable in soil and freshwater environments with estimated 90% biodegradation times of 504–580 and 604–845 days, respectively, while PBAT takes 971 days in soil and 395 days in freshwater.

Hydrophilic and Biodegradable PBAT Copolyesters Prepared from Chemically Recycled Resources

“…Figure d shows the energy storage modulus ( G ′) and loss modulus ( G ″) of R-PBAT and PBAT copolyester materials as a function of the angular frequency (ω) at 150 °C. , The energy storage modulus ( G ′) describes the elastic properties of the material or the amount of energy stored during deformation, and the localized chain motion in the high-frequency region and the chain entanglement behavior in the low-frequency region are important factors affecting G ′. As shown in Figure d, the G ′ of both R-PBAT and PBAT copolyesters showed an increasing trend with the increase of ω, and the increasing process of R-PBAT in the range of 0.1–100 rad/s was higher than that of the PBAT copolyester.…”

Techno-Economic Analysis and Life Cycle Assessment of the Production of Biodegradable Polyaliphatic–Polyaromatic Polyesters

“…For PPAT, AA is the main contributor for the energy consumption (48% of total energy requirement) for the fossil-based route, while TPA is the main driver in energy consumption (40% of total energy requirement) in the biobased route. In addition, Zheng et al reported that films compared to the PBAT compression-molded films, the higher tensile modulus (up to 76%) can be achieved by PPAT compression-molded . The improved mechanical property of PPAT suggests that a smaller amount of polymer resin is needed to achieve the same functionality as PBAT for some certain applications, indicating that the energy consumed in the production process for PPAT films can be further decreased.…”

“…20 The substitution of 1,4 BDO in PBAT with 1,5-pentanediol (1,5-PDO) [to produce poly(pentylene-adipate terephthalate) (PPAT)] can give a 76% higher tensile modulus than PBAT, improving the overall mechanical properties of the polyester while still maintaining good soil biodegradability. 21 This can reduce the amount of plastic in the biodegradable films. Another important disadvantage of currently commercial PBAT is that 1,4-BDO and TPA are derived from fossil-based sources, resulting in a large carbon footprint and high fossil resource usage in their production.…”

“…In addition, Zheng et al reported that films compared to the PBAT compression-molded films, the higher tensile modulus (up to 76%) can be achieved by PPAT compression-molded. 21 The improved mechanical property of PPAT suggests that a smaller amount of polymer resin is needed to achieve the same functionality as PBAT for some certain applications, indicating that the energy consumed in the production process for PPAT films can be further decreased. This allows more energy savings by replacing PBAT with PPAT.…”

Ductile Copolyesters Prepared Using Succinic Acid, 1,4-Butanediol, and Bis(2-hydroxyethyl) Terephthalate with Minimizing Generation of Tetrahydrofuran

“…However, in certain sectors, such as agriculture, recycling can be inherently challenging, making the promotion or enforcement of biodegradable polymers a viable alternative [ 10 , 11 , 12 ]. In this context, various types of biodegradable polymers have been explored [ 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ]. While cellulose and starch-based polymers remain significant sources of biodegradable materials, there has been a recent surge in the production capacity of biodegradable synthetic polyesters like PBAT [poly(butylene adipate- co -terephthalate)] and PLA (polylactide) [ 29 , 30 ].…”