Study On PBS Composites Modified With Talc And Montmorillonite

Poly （butylene succinate）（PBS） as the biodegradable material with goodperformance, can effectively relieve the pressure of the environment caused bytraditional plastic waste. However, its cost is higher than the conventional plasticrelatively and the application has been limited owing to people’s high demandsfor the materials in practice. In this thesis, PBS composites modified withorganic montmorillonite （OMMT） and talc were prepared by milling-pressingand mixing-injection molding process. Also organic OMMT and talc treated withKH560as a coupling agent were studied. The results of this paper are as follows:（1）In comparison with several processes, the method of milling-pressingand the method of mixing-injection molding were better for choice with theireasy operation and good quality of products. And the SEM pictures show thatthe fillers could be dispersed throughout the PBS matrix evenly. Therefore,these two processes were acted as the main processes of the compositespreparation in this paper.（2）A series of film composites and spline composites were prepared bymelt intercalating PBS, OMMT and KH560modified OMMT, using differentprocesses of open milling-pressing and internal mixing-injection molding. Theresults showed that OMMT was well-distributed in the matrix of the PBS whicheffectively came into the OMMT lamellars. The results calculated from XRDshowed that PBS/OMMT spline layer spacing increases. The nanocompositesprepared by milling-pressing had peelable structures, while prepared bymixing-injection had intercalational structures.The mechanical properties and thermal stabilies of PBS/OMMT splinesprepared through mixing-injection were better than pure PBS. With DK2contentof2wt.%and KH560content of3wt.%（accounted for the DK2）, the tensilestrength and the elongation at break are33.7MPa and223.8%, while T_5%is334℃. Thus, the DK2content of2wt.%for the composite and the KH560content of3wt.%for DK2is the best dosage for the preparation of PBS/OMMTsplines. The PBS/OMMT film prepared through milling-pressing with DK2contentof2wt.%and KH560content of3wt.%（accounted for the DK2） has both goodperfomances and thermal properties. Its tensile strength and the elongation atbreak are33.5MPa and47.3%, while T_5%is342℃.（3）Aseries of PBS/talc composites were successfully prepared with PBS,talc and talc modified with KH560by melt blending using mixing-injectionmolding process. Results indicate that talc is uniformly dispersed in PBS matrix,the phase interface between modified talc and PBS matrix is vague through SEM.Thus, the satisfactory filled composite is obtained.Tensile strength, flexural modulus, flexural strength of PBS/talc compositesincreased significantly relative to pure PBS. The elongation at break declinedwith talc content of composites increased. Both impact strength and elongation atbreak reach the maximum which are37MPa and37.2%when talc content is20wt.%and KH560content is3wt.%of it.Thermal stability of PBS/talc composites significantly improved relative topure PBS. T_5%increased with the talc content increasing, and decreased with theKH560content increasing. When talc content is40wt.%and KH560content is1wt.%of talc, T_5% is349℃and half-life temperature is395℃, which has thebest thermal properties.（4）A series of PBS/OMMT/talc composites were prepared by meltblending PBS, KH560modified OMMT and talc with mixing-injection moldingprocess. Results show that OMMT and talc diversed uniformely in PBS matrixand the phase interface of KH560modified talc and PBS matrix is vague. Theinterlayer spacing increases from2.74nm to3.49nm, calculated by XRD, whichproves partly intercalated composites were obtained successfully.Tensile strength, flexural strength, flexural modulus and impact strength ofPBS/OMMT/talc composites significantly increased relative to pure PBS.PBSYS2performed the best mechnical properties of the PBS/OMMT/talccomposites. The tensile strength, flexural strength, flexural modulus and impactstrength of PBSYS2are34.6MPa,54.1MPa,354.5MPa and12.29MPa, whichare all better than that of pure PBS. However, elongation at break of compositesdeclined.Relative to pure PBS, T_5%of PBS/OMMT/talc changed a lot, which got the largest332℃in PBSYS1and PBSYS2. Comprehensively, the best addition ofPBS/OMMT/talc composites was2wt.%DK2,18wt.%talc and KH5603wt.%oftalc.（5）Considering all of the three series of composites, the order of flexuralstrength and flexural modulus is: PBSYS> PBSYH> PBSYM, the order oftensile strength is: PBSYM> PBSYS> PBSYH, the order of the elongation atbreak rate is: PBSYM> PBSYS> PBSYH.