Study on the properties of PBT copolyester modified with dimethyl 2,6-naphthalenedioate
A series of polyethylene terephthalate-2,6-naphthalenedioic acid butanediol copolyesters(PBNT)with varying DMN to PTA molar ratios were created by copolymerizing dimethyl 2,6-naphthalenedicarbox-ylate(DMN)with 1,4-butanediol(BDO)and terephthalic acid(PTA)as a modified monomer in order to en-hance the mechanical and thermal properties of PBT and expand its range of applications.Using an infrared spec-trometer,differential scanning calorimeter,thermogravimetric analyzer,hardness tester,and universal material tes-ting equipment,describe the composition and characteristics of copolyesters.According to the results,the copolyester's melting point temperature(Tm),melting crystallization temperature(Tmc),and crystallinity(Xa)ex-hibited a trend of first declining and then increasing within a specific range as the DMN addition increased.The glass transition temperature(Tg)rose dramatically,reaching 64.5℃with 70%DMN addition.The copolyester's beginning and maximum decomposition temperatures(Td,max)increased progressively.As the DMN concentration grew,the copolyester spline's tensile strength and hardness improved,but its elongation at break decreased.The tensile strength and elongation at break are 57 MPa and 34%,respectively,when the DMN content approaches 70%.In conclusion,PBNT has better glass transition temperature,tensile strength,and thermal stability than pure PBT.Nevertheless,the notch impact strength is trending downward,suggesting that it is more sensitive to notches.
NETL
NSTL
万方数据
