Study On The Synthesis And Properties Of Bio-based Polyesteramide Thermoplastic Elastomer

Elastomers have been applied extensively in many fields due to its comprehensive properties.Compared to the rubbers,thermoplastic elastomer has advantages of low costs,convenient operation and non-toxicity during production.It is of great significance to protect environment.Bio-based materials as a substitute for crude oil to produce thermoplastic elastomer can reduce the environmental pollution.As a novel kind of thermoplastic elastomer,polyesteramide(PEA)thermoplastic elastomer comprehens the advantages of polyester and polyamide.The main goal of this paper is to synthesize a new kind of bio-based polyesteramide(BPEA)thermoplastic elastomer.Firstly,this thesis using a series of bio-based monomers,(succinic acid,fumaric acid,sebacic acid,1,3-propanediol,1,4-butanediol,etc.),synthesize the prepolyester with terminal carboxyl group,and the prepolyester molecular weights were controlled by measuring the acid-value.Then followed with polycondensation of polyesteramide(PEA)with the amidation reaction of carboxyl group with 1,6-Hexanediamine.The bio-based sources of polyesteramide elastomer are more than 80%.Studies on the research of catalyst,reaction temperature,reaction time,vacuum degree,stabilizers and antioxidants and other various conditions,the ideal bio-based polyesteramine can be fabricated with the optimum production process conditions.Secondly,the thesis investigates the structure and properties of the bio-base polyesteramide elastomers.The relative molecular weight of BPEA was measured by the viscosity method.The polyesteramide was characterized by infrared spectrometer(FT-IR)and nuclear magnetic resonance apparatus(1H-NMR).The results show that the peaks of the functional characteristic of the polyesteramide showed up,proving that the paper has synthesized the target products.The thernal properties were studied by differential scanning calorimetric(DSC)and thermogravimetric analyzer(TGA).The DSC of products shows that the glass transition temperature Tg of polyesteramide is below-40 degrees.Polyesteramide presentes two melting temperatures and two thermal decomposition peaks which verify two kinds structure in the molecular chain.The TG of products shows that,polyesteramide is thermal stability within 300 ? which meets the demand of processing conditions.The water absorption in distilled water at 25 ?,hydrolytic degradation behavior in solution(pH=4.0,6.8,9.2)at 25 ?,solvent resistance performance in different solvents at room temperature were also investigated,respectively.And the experimental results show that the structure of BPEA and the pH value of the degradation medium have great effect on the water absorption and the degradation behavior.The Stress-strain test and hardness test results show that the polyesteramide elastomer has a adequate mechanical property which meets the basic characteristics of thermoplastic elastomer.