The Composite of High-Density Polyethylene/Polycarbonate Prepared by a New Corotating Non-twin Screws Extruder

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1 The Cmpsite f High-Density Plyethylene/Plycarbnate Prepared by a New Crtating Nn-twin Screws Extruder Zhexing li 1,2, Xiangfang Peng 1, Tairng Kuang 1, Binyi Chen 1 *, Baiping Xu 2 * 1. Natinal Engineering Research Center f Nvel Equipment fr Plymer Prcessing, The Key Labratry f Plymer Prcessing Engineering f Ministry f Educatin, Suth China University f Technlgy, Guangzhu, , PR China 2. Advanced Research Center fr Plymer Prcessing Engineering f Guangdng Prvince, Technlgy Develpment Center fr Plymer Prcessing Engineering f Guangdng Clleges and Universities, Guangdng Industry Technical Cllege, Guangzhu , China Abstract In this paper, the cmpsites f High-Density Plyethylene /Plycarbnate were prepared by a new crtating nn-twin screws extruder. The WANCE electrnic universal testing machine, Antn Paar rtatinal rhemeter, differential scanning calrimetry analysis and scanning electrn micrscpe (SEM) were used t test cmpsites in ur experiments t shw the ability and characteristic f new equipment. The results shw that the new equipment has excellent mixing ability and the ptential t replace the traditinal twinscrew extruder with the develpment f cmpsite materials. Intrductin The gemetry f fully intermeshing twin screw equipment has been investigated fr a lng time. The traditinal c-rtating twin screws extruder (TSE) used in industry have identical crss sectin arranged at the certain phase angle and rtate at the same speed. Fr imprving the ability f plymer blends, the Nn-twin Screws Extruder (NTSE) was invented by Xu [1]. The extruder is cmpsed f tw screws with the same diameter and a speed rati f 2.0. The picture f real prducts and crss sectins fr screws in c-rtating kneading disk pairs are shwn in Figure 1. Cmparing with TSE, materials have mre chance t be expsed t the nip regins in NTSE t accelerate the melting. Blending tw kinds f materials is a cmmn way f plastics mdificatin [2-4]. The experiments find that the melt pint f ipp and the degree f crystallinity increased with the increase f the vibratin amplitude [5]. Beynd that, many schlar cncluded that the melted drps in plymer prcessing were mre efficiently brken under elngatinal flw [6-8]. Based n this thery, Qu [9] invented a nvel plasticizing apparatus knwn as the van extruder t generate the higher stress and the dynamical elngatinal flw. Fr HDPE/PC cmpsites, the mst imprtant prblem is that the tw-phase incmpatible interface *Crrespnding Authr : mebychen@scut.edu.cn xubaiping2003@163.cm effect. The previus wrk f End s [10] take the styrene-(ethylene/butene) blck SEBS cplymer as slubilizer, finding that SEBs culd decrease the interfacial tensin f PE/PC cmpsite. And it s seriusly affected the mechanical prperties f the blend materials. Even the prperty f sme cmpsites were nt slubilized shw the sum rule with minus deviatin. In ur wrk, Xu [11] intrduce the asymmetrical effect int the screw channel t enhance the chatic mixing and elngatinal flw. S, a nvel c-rtating nn-twin screws extruder was fabricated. The further 2D numerical simulatin shwed that the distributive mixing and dispersive mixing in NTSE were superir t thse in TSE [12]. The high density plyethylene (HDPE) is a kind f high crystalline and nn-plar thermplastic resin [13-14]. Fr plycarbnate (PC), it s a plymer mlecular chain cntaining carbnate grups. Due t the special nature f the plycarbnate structure, it has nw becme the tp five fastest grwing engineering plastics in general engineering plastics [15-17]. Fr all the reasns mentined abve, a new extruder was designed t prduce HDPE / PC incmpatible cmpsites. Materials Experimental The matrix HDPE (DGDA6098) was generusly supplied by QiLu Petrleum Chemical C. The melt flw index and density prvided by the supplier were 9.0 g/10 min and g/cm3, respectively. Which was plymer matrix in this study. Cmmercial available PC (201-22) with melt flw index (FMI) = 22g/10min was purchased frm LG-DOW C. Ltd. The density was abut 1.2 g/cm3 and the Misture Absrptin was 0.32 %. Table 1 lists sme parameters f prcessing. The HDPE was dried in an ven at 80 C fr 2h t remval surface misture befre prcessing. The PC pellets were dried at 100 C fr 4h. The binary blends were finished in NTSE. The extruded strands were quenched immediately SPE ANTEC Anaheim 2017 / 149

2 Figure 1. The picture f real prducts and crss sectins fr screws in crtating kneading disk pairs Table 1. Prcessing cnditins f blends and sample name Screw speed (rpm) 50rpm HDPE-1 HDPE-2 HDPE-3 Prcessing temperature (C) Rate f feeding kg/h HDPE/PC=9:1 HDPE/PC=8:2 HDPE/PC=6:4 after extrusin in a water bath kept at rm temperature. The HDPE/PC with different weight ratis f 90/10, 80/20 and 60/40 were directly extruded thrugh the die with 3mmhles and the sample was pelletized after cling. The sample names are als listed in Table 1. Mechanical Testing Tensile prperties measurements were dne at rm temperature. The samples used JT130 injectin mlding prvided by Guangdng Hengsheng Machinery C. Ltd. ETM104B electrnic universal testing machine was used, which was prduced by WANCE systems (China) C. Ltd. The tensile speed was kept at 50 mm/min. The dimensins f the testing specimens were carefully machined t be standard 4 mm thick by dumbbell mld. Five specimens were used in each test t btain the average value. Rhelgical Measurements The rhelgical prperties f all f the samples under scillatry shear flw were investigated with a Antn Paar MCR302 Rhemeter. A parallel-plate gemetry (φ= 25 mm) with a fixed gap f 1 mm was selected fr all the tests. The samples were first cut int 25 mm diameter circular films with the thickness f 1 mm. T ensure that all f the samples in the linear viscelastic regin t test, all samples strain amplitude is set t 1% in the frequency sweep mdes. The frequency sweep was run frm high-t-lw frequency mde at an angular range f rad s-1 at a temperature f 220 C. Mrphlgical Observatin Mrphlgy f the blends was analyzed n a (QUANTA FEG250) Field Emissin Scanning Electrn Micrscpe(SEM). We put the specimen in liquid nitrgen fr tw mre hurs and then fractured it. The surface was cvered with a layer f gld t make it cnductive prir t bservatin. Image-Pr Plus sftware was used fr the dispersed particle size statistics. Differential Scanning Calrimetry (DSC) Thermal analysis was perfrmed using a DSC (204C Netzsch, Germany) in a nitrgen atmsphere. The tw different samples f HDPE/PC blends with a weight f 4 mg were heated frm rm temperature t 250 C first at -1 a heating rate f 10 C min and kept isthermally fr 5 min t eliminate any thermal histry. Then the samples were cled t 50 C with the same heating rate 10 C -1 min. The third stage f DSC tests, cling samples were heated t 250 C again t test plymer melting SPE ANTEC Anaheim 2017 / 150

prcess and the thermgram was recrded at the same time. Results and Dsicussin Mechanical Prperty Figure 2 shws the tensile strength, bending strength and flexural mdulus f the cmpsites.

3 prcess and the thermgram was recrded at the same time. Results and Dsicussin Mechanical Prperty Figure 2 shws the tensile strength, bending strength and flexural mdulus f the cmpsites. Frm the illustratin, we culd see that when the cntents f plycarbnate frm 10 wt% increase t 20 wt%, the tensile strength decrease, but when the cntents increase t 30 wt%, the tensile strength imprved. The bending strength and flexural mdulus increase with the imprvement f PC cntent. It s ease t understand that a certain amunt f PC can imprve elasticity f PO matrix. But HDPE and PC is cmpletely incmpatible systems, bad interface is nt cnducive t imprving the strength f the cmpsite material. Which induced the weaker tensile strength f 20 wt% PC cntents. Cnsistent with what we mentined earlier, this phenmenn has a very clse relatinship with the dispersed phase interface, we culd further research it frm SEM phtgraphs. Figure 3 shwn the strage mdulus (Pa) and cmplex viscsity (Pa s) f cmpsite. In general, the incrpratin f inrganic particles int the plymer can increase the strage mdulus and viscsity f the plymer [18]. The results shw that the strage mdulus and cmplex viscsity f the cmpsites decrease with the increase f PC cntent. We can explain it by the immiscible f tw different materials. When the cmpsite material is in a mlten state, the PC phase is nt an inrganic particle and at the same time there is n gd interface with HDPE material. S, the strage mdulus and cmplex viscsity decreased with PC cntents increase. (a) (a) (b) Figure 3. Frequency sweep results f strage mdulus and cmplex viscsity as a functin f rtate speed (a) strage mdulus (b) cmplex viscsity. Mrphlgy Observatin (b) Figure 2. Mechanical prperties as functins f blend cmpsitin; (a) tensile strength, (b) bending strength and mdulus. Althugh the mechanical prperty f cmpsite is nt utstanding, in view f the physical prperties f matrix, bth the tensile strength and the bending prperty are remarkably imprved. Rhelgical Prperty When the PC cntent increase t 40 wt%, The cmplex phase structure has bth c-cntinuus phase and sea islands structure. The structure f the incmpatible system is cnsistent with the thery [19], and the mixing perfrmance f the new type f extrusin is als prved. It s a general cnsensus that the dispersed phase size and shape f cmpsite decide the perfrmance f blends. Figure 4 are HDPE/PC blend SEM phtgraphs f different cmpnents. As it's shwn, the phase mrphlgy changes markedly with the increase f PC SPE ANTEC Anaheim 2017 / 151

Figure 4. SEM micrgraphs f the extrusin samples. cntent. The dispersed phase mrphlgy are similar when the PC cntent is less than 20%, but there are sme difference in the size f the dispersed phase.

4 Figure 4. SEM micrgraphs f the extrusin samples. cntent. The dispersed phase mrphlgy are similar when the PC cntent is less than 20%, but there are sme difference in the size f the dispersed phase. It is easy t bserve the tw-phase incmpatible interface in the figure, but the excellent mixing ability f the NTSE makes the mixing f the tw phases better than the cnventinal equipment [20]. Thermal Prperty Analysis Previus wrk discussed Mechanical prperties rhelgical behavir and micr-mrphlgy f cmpsites prepared by NTSE. HDPE is a plymer having a high degree f crystallinity, the additin f the PC phase inevitably affects it. Frm figure 5, we culd find that there s n significant change f Tm. We can find that the melting enthalpy f the plymer is reduced with PC cntent increase. But when the enthalpy f full crystallizatin is 293 J/g, the crystallinity f HDPE-1 and HDPE-3 are 66.4% and 67.6%, respectively. The crystallinity increased slightly with the increase f PC cntent. The crystallinity is calculated as fllws: fc = Xa and DH m X a DH m0 (1) DH m0 are the HDPE cntent f the blends and The mechanical prperties, mrphlgy prperties and crystallizatin prperty f the HDPE/PC blends extruded by the nvel self-made c-rtating nn-twin screws extruder were investigated. Althugh the nvel NTSE had nly tw thirds screw length cmpared with traditinal twin screws extruder and less kneading disks, cmpsites btained excellent verall perfrmance. The tensile strength, bending mdulus, flexural mdulus f HDPE/PC blends extruded by NTSE indicates that the strng mixing ability can imprve the mechanical prperties f the incmpatible system. Rhelgical behavir and SEM indicate that viscsity and dispersed phase mrphlgy are cnsistent with incmpatible cmpsites prepared by traditinal extruder. The DSC test shwed that the crystalline prperties f the cmpsites changed, the additin f PC phase increased the crystallinity f the HDPE material. The results shw that the self-made NTSE can be used t prepare the incmpatible cmpsites, and the mechanical prperties f the cmpsites are imprved and the micr-dispersin and distributin are excellent. In cnclusin, the HDPE / PC cmpsites btained gd mixing effect thrugh the intrductin f chatic frce field. Therefre, NTSE prved t be an effective plymer prcessing equipment. With the further develpment f the equipment, it is expected t replace the traditinal twinscrew extruder. enthalpy at full crystallizatin respectively. Acknwledgements The authrs acknwledge the financial supprt f the Natinal Natural Science Fundatin f China (N , N ), the Guangdng Nature Science Fundatin (N.S , N ), the Guangdng Public Welfare Research Fund (N.2014B ), the Fundamental Research Funds fr the Central Universities (N.2015ZM099), and the Opening Prject f Key Labratry f Plymer Prcessing Engineering (Suth China University f Technlgy), Ministry f Educatin. Figure 5. Secnd heating DSC curves f cmpsites. Cnclusins References 1. Xu B, Wang M, et al. CN. Patent WO/2011/ (2011). SPE ANTEC Anaheim 2017 / 152

5 2. Carr O, Gzzi G, Sants L F, et al. Translatinal Materials Research. 2, 1 (2015). 3. Hng H E, Zhu L, Lei D, et al. Zhngnan Daxue Xueba. 45, 383 (2014). 4. Kuang, Tairng, Chang, L., Chen, F.et al. Carbn. 105, 305 (2016). 5. Qu J, He G, He H, et al. Eurpean Plymer Jurnal. 40, 1849 (2004). 6. He H, Chen L, Sun S, et al. Fibers and Plymers. 15, 744(2014). 7. Ku T H, Lin C A. Textile Research Jurnal. 84, 932 (2014). 8. Wen J S, Liang Y H, Chen Z M. Advanced Materials Research. 421, 415 (2011). 9. Qu J. CN. Patent (2009). 10. End S, Min K, White J L, et al. Plymer Engineering & Science. 26, 45 (1986). 11. B. P. Xu, CN. Patent (2010). 12. Xu B P, Yu H W. Advanced Materials Research. 560, 1091 (2012). 13. Ellumi, A.; Makhluf, M.; Elleuchi, A.; Bradai, C. Plymer-Plastics Technlgy and Engineering. 10, 55 (2016). 14. Seven, K. M.; Cgen, J. M.; Gilchrist, J. F. Plymer Engineering & Science. 56, 541 (2016). 15. Srinivasababu, N.; Kumar, K. P.; Srikar, G. Applied Mechanics & Materials. 766, 27 (2015). 16. Faye, A.; Parmeswaran, V.; Basu, S. Prcedia Materials Science. 3, 1304 (2014). 17. Yee A F, Smith S A. Macrmlecules, 14, 253 (1981). 18. Peng X, Li K C, Jing X, et al. Rsc Advances. 6, 3176 (2015). 19. Yin B, Zha Y, Yu R Z, et al. Plymer Engineering & Science. 47, 14 (2007). 20. Lu J S, Xu B P, Yu H W, et al. Fibers and Plymers. 16, 95 (2015). SPE ANTEC Anaheim 2017 / 153

The effects of glass powder on some mechanical properties of engineering thermoplastics

The effects of glass powder on some mechanical properties of engineering thermoplastics J. Natn.Sci Fundatin Sri Lanka 2007 35(1): 13-17 The effects f glass pwder n sme mechanical prperties f engineering thermplastics L.Karunanayake Department f Chemistry, University f Sri Jayewardenepura,