A Special Interface Structure On The Properties Of Biomass-based Polycaprolactone Composites

In this thesis,a series of biodegradable biomass-based PCL composites were prepared by melt blending in the intensive mixer.Firstly,by changing the kind of biomass,the effects of polyurethane prepolymer(PUP)on the stucture and properties of soy isolate protein(SPI)/PCL composites were investigated.And then the synthesis conditions of p-phthaloyl chloride prepolymer(PCP)were explored,and it was further explored whether the prepolymer could promote the formation of the interfacial structure,the effects of the interfacial structure on the structure and properties of starch/PCL composites were studied.Finally,the effects of different acid chloride prepolymer on the structure and properties of starch/PCL composites were investigated.This article mainly consists of the following three parts.(1)The effects of polyurethane prepolymer(PUP)on the structure and properties of soybean isolate protein(SPI)/PCL composites were studied.The results showed that,the new interfacial structure can also be formed between SPI and PCL in the SPI/PCL composites compatibilized with PUP.After changing the kind of biomass,urethane linkages were formed from the reaction between multiisocyanates of PUP layer and the hydroxyl groups and amidogen groups of SPI.Meanwhile,the PCL soft segments in PUP layer could interact with PCL matrix through PCL-PCL physical crystallinity,so that the interfacial adhesion between the soybean isolate protein and PCL matrix was enhanced,that is,the compatibility was improved.Therefore,the mechanical properties and water resistance of the SPI/PCL composites with PUP were improved obviously compared with the SPI/PCL composites without PUP.(2)Structure and properties of starch/PCL composites compatibilized with PCP were studied.According to the test results,the interfacial structure was formed between starch and PCL matrix in the starch/PCL composite material compatibilized with PCP.On one hand,Ester linkages were formed from the reaction between the terminal groups of PCP and the hydroxyl groups of starch.On the other hand,the PCL segments in PCP could interact with PCL matrix through PCL-PCL physical crystallization,so that the interfacial adhesion between starch and PCL matrix was enhanced in the starch/PCL composite material compatibilized with PCP.Therefore,the compatibilizer(PCP)can effectively enhance the the compatibility between starch and PCL in starch/PCL composites.Compared with the starch/PCL composites without the PCP compatibilizer,the mechanical properties,water resistance and thermal performance of the starch/PCL composites with the PCP compatibilizer were more excellent.(3)The effects of different types of acid chloride on the structure and properties of starch/PCL composites were investigated.The results of the structural characteristics,mechanical properties,water absorption and thermal properties of the three composites all showed,compared with the S50P50 composite material,the interaction between starch and PCL in the PMS50P50,AMS50P50 and FMS50P50 containing compatibilizers was improved.However,compared with the saturated and unsaturated aliphatic acid chloride prepolymer,the aromatic acid chloride prepolymer has a weaker microphase separation ability between the acyl chloride segment and the PCL,so that the interaction between the starch and PCL matrix in the PMS50P50 composite with the aromatic acid chloride prepolymer was stronger.