Preparation And Properties Study Of The Modified Poly(butylene Succinate)

The synthesized polymer materials have been the largest used material of human, which emerged in 21 century. Its annual outputs reach more than 140 million tons. It gives people a great of convenience as well as the inevitable influence of environmental pollution, such as in agriculture, packaging and medical industries with a shorter using cycle. Therefore, the development of biodegradable polymer materials has become very important to relieve this pressure. Aliphatic polyester has become a hot focus of current research. Poly(butylene succinate) (PBS) is a typical semi-crystalline thermoplastics with high melting point. It has a wide range of applications, so, it has an important research value. However, PBS can not meet the performance requirements in different area, so, it is necessary to modify it for further application of PBS. In this paper, PBS was modified by copolymerization and blending with PHAs to improve its properties.The non-isothermal crystallization kinetics of PBS/PHAs blends were investigated by differential scanning calorimetry (DSC). The Avrami equation modified by Jeziorny was used to fit the primary stage of non-isothermal crystallization of various blends. The results suggest that the PHAs accelerate the crystallization rate of the blends; however, when the PHAs reaches a certain content the crystallization rate decreased. The crystal growth dimension of PBS was almost not affected by the PHAs. The nucleation of PBS is homogeneous and the crystal growth dimension is nearly three-dimensional growth. By addition of PHAs, crystallization temperature of PBS first increased and then decreased. The crystallization activation energy was estimated by Kissinger equation, which decreased first and then decreased as PHAs increasing. The isothermal crystallization kinetics of blends could be well described with the Avrami equation. The mechanism of PBS was almost not affected by the PHAs. The crystallization activation energy was estimated by Friedman equation.Biodegradable aliphatic poly(butylene succinate-co-diethylene succinate) (PBDEGS) were synthesized by using succinic acid and diethylene glycol through a two step polycondensation with titanium tetraisoproxide (TTP) as catalyzer and polyphosphate (PPA) as the stablilizer at high temperature. DSC was used to investigate the melting, crystallization behavior and non-isothermal crystallization kinetics of this copolyester. The melting behavior showed that the melting temperature of the copolyester decreased gradually with increaseing of diethylene glycol in the copolyester. The crystallization mechanism of PBDEGSs were analyzed by the Avrami equation. The results showed that the DEG chains segments affected the crystallization of PBS and decreased overall crystallization rate in some extent. The Mo analysis showed similar results. At the same time, because of the flexible ether bond existed in the DEG molecules, the crystallization activation energy of PBDEGSs is obviously lower than that of PBS.