LU Pan-feng, YAN Xiu-wei, LIU Min, MI Pu-ke, LIU Sheng-ping
Abstract (
2372 )
The necessity of modification of PET used as engineering plastics is introduced. Mainly for its low impact strength and poor crystallization properties, introducing the modified methods and the latest advances of PET. The methods include blending modification、nanocomposites modification and adding nucleating agent or nucleating accelerant, their mechanisms are simply introduced. At last, a summary on production and application of PET was given.
XU Jia-zhuang, ZHONG Gan-ji, LI Zhong-ming
Abstract (
5084 )
The advance in the study on transcrystalline interface layers (TL) of the fiber reinforced polypropylene composites has been reviewed in this paper. It includes the formation and growth of the different kinds of the TL (α-and β-TL), and the influences on the formation and growth of TL extensively, as well as the effect of interface TL on the mechanical properties of the composites.
CHEN Hui-min, CHEN De-liang, ZHANG Rui
Abstract (
2153 )
This paper reviews advances in the modification of PP-based composites with micro-/nano-sized inorganic rigid particles, with emphasis on reviewing the effects of micro-sized, nano-sized and micro-/nano-sized compounded inorganic particles on the mechanical and functional properties of the PP-based composites. A general conclusion is that the smaller the inorganic particles, the more favorable the composites are strengthened and toughened, and that the modification of the inorganic particles has a critical influence on the interfaces of the composites, which then affect the microstructures and properties remarkably. The addition of micro-sized inorganic particles can improve the impact property and rigidity of the PP-based composites, but usually reduces the strength properties; on the other hand, nano-sized inorganic particles have the ability to enhance the strength, toughness, and modulus of the PP-based composites. The properties of the PP composites filled with compounded fillers are better than those of the PP composites filled with single fillers.
FU Meng-yue, LIU Ji-chun, LI Qing-yuan, ZHANG Yu-qing
Abstract (
4897 )
The intercalated nanocomposites of polystyrene (PS) were prepared by means of direct melt blending of polystyrene and organic montmorillonite (OMMT). The flame-retardant property of the nanocomposites was investigated by employing horizontal burning, oxygen index, thermogravimetry and high temperature treating methods. It was shown that the introduction of OMMT can decrease the horizontal burning speed and improve the oxygen index of the nanocomposites. The thermal stability and flame retardancy of the nanocomposites are enhanced noticeably. It is believed that the shielding and obstructing effects of silicate layer to the transfer of heat, oxygen and degradation products are responsible for the increase of flame retardancy.
WANG Yu, YANG Wei, ZHAI Yuan-ming, XIE Bang-hu, YANG Ming-bo
Abstract (
2133 )
The effect of relative molecular weight and its distribution of ethylene-α-olefin copolymers on the relationship between storage modulus (G') or loss modulus (G") and frequency (ω) and between storage modulus and loss modulus were studied by investigating the dynamic rheological behavior of the samples with various relative molecular weight and various polydispersity. The results indicated that the slopes of the G'~ω, G"~ω, G'~G" curves not only were smaller than those of the monodisperse polymers, but also decreased with relative molecular weight or its distribution increasing.
ZHEN Wei-jun, MA Xiao-hui, YUAN Long-fei, PANG Gui-lin, LIU Yue-e
Abstract (
2345 )
PLA /OMMT intercalation nanocomposite was synthesised by in-situ intercalation polymerization with organomontmorillonite (OMMT) and lactic acid monomer. The structure and morphology of PLA/OMMT intercalation nanocomposite were characterized by FT -IR , XRD，TEM. The degradability of PLA/OMMT intercalation nanocomposite was also studied. The FT –IR spectra indicated that the OMMT was exfoliated and dispersed into the PLA matrix during the polymerization. XRD shew that the layer spacings of MMT, OMMT and PLA/OMMT intercalation nanocomposite were 1.260nm, 1.993 nm and 2.287 nm individually, which shew the swellable silicate layers were intercalated by the PLA matrix, and in-situ intercalation polymerization was done. TEM images demonstrated that the PLA/OMMT intercalation nanocomposite was of intercalative structure, which accorded with the results of FT –IR and XRD. The results of the degradation of PLA/OMMT intercalation nanocomposite showed the media degradability rank was as following : NaOH>HCl>deionied water. In PBS buffer solution the intrinsic viscosity of PLA/OMMT intercalation nanocomposite was declined as the degrading time .It was shown that the degradability rate of PLA/OMMT intercalation nanocomposite was faster than that of PLA, which demonstrated that the degradability of PLA/OMMT intercalation nanocomposite was improved by the MMT 。
PENG Wei-ya, WANG Chen-yi, TAN Jia-hui, WANG Ying, LI Guang
Abstract (
3126 )
A new bisphenol monomer (3,4–difluoro)phenylhydroquinone, was thesised in a three-step synthesis. Fluoropoly (aryl ether ketone)s (FPAEK) and Fluoropoly (aryl ether sulfone)s (FPAEF) were prepared from the three bisphenol monomers and 4,4′ -diflourodiphenylketone or bis-(4- chlorophenyl) sulfone via a nucelophilic aromatic substitution polycondensation, respectively. The structures of the monomer and polymers were confirmed by 1H-NMR and FT-IR, and the properties of FPAEK and FPAEF were also studied by DSC, TGA, WXRD, etc. It was found FPAEK and FPAEF show high temperature stability, i.e the 5% weight loss temperatures were above 527℃ and 507℃ in N2, and their glass transition temperatures (Tg) ranged from 150℃ to 159℃ for FPAEK and from 177℃ to 196℃ for FPAEF in N2. Furthermore, these polymers have good solubility in some polar aprotic solvents such as NMP, DMAc, CHCl3, etc, which is an important advantage to process them for practical applications.
SUN Xiao-wei, TAI Li-min
Abstract (
3678 )
In this article, the compatibility and degradable performance of blends of starch/PS-g-MAH were studied. The grafting product was characterized by infrared spectra. Content of MAH in product was determined by titration. It is showed that PS-g-MAH was produced. The influence of different contents of MAH to the compatibility of starch/PS was analyzes by SEM. Experiments show that, adding MAH can significantly improve the compatibility between starch and PS, When PS/MAH=95/5, the graft rate achieved the best value 2.27%. The degradable performance of pure starch/PS and starch/MAH-g-PS samples was compared. The degradation rate of starch/PS-g-MAH blending was 20.09 % after 40 d, less than starch/PS.
WANG Pei-zhang, LIU Xue
Abstract (
1958 )
The thermoplastic starch was grafted with 6 different monomers in melt state during extrusion. The results of IR and grafting ratio shows that the highest grafting ratio was starch-g-acrylic acid, the grafting ratio was obtained at 2.4 %. IR, XRD, Haake torque rheometer and polarizing microscope were used to investigate the influence of crystal behavior, rheological property and cells configuration of grafted starch/PE-LD. Results indicate that the grafted starch improved compatibility of starch/PE-LD compounds. Starch-g-acrylic acid/PE-LD compound showed the best properties. The dose of acrylic acid was 3 phr.
HE Bin, YANG Yong, MA Xiao-xiong
Abstract (
117 )
XUE Hai-jiao, DING Xue-jia, LI Hong-bo, WU Heng-lan, TANG Bin
Abstract (
3931 )
The rigid polyurethane foam (RPUF) blown by water with 0.5mm cell diameter was prepared. Effect of content of triethanolamine on foaming time, apparent density, thermal conductivity and mechanical properties of RPUF product was studied. Triethanolamine can accelerate the main reactions of system, meanwhile is cross linker due to its special molecular structure. The foaming time was shorter with the triethanolamine ratio increasing. At the same time, the apparent density, coefficient of thermal conductivity and strength of product descended(before 7 phr) then ascended(after 7 phr), while the cell diameter and percentage of elongation at break of product have reversed trends.
XIAO Jian-hua, LIU He-sheng, HUANG Xing-yuan, XU Lei, ZHANG Xiao-xia
Abstract (
5772 )
The extrudate reduction phenomenon of melten polymer in the process of gas-assisted extrusion(GAE) forming was systemic studied through experiments, it is analyzed that the two main reason causing the reduction of extrudate was semi-solid melting film and melt down。The essential reason for semi-solid melting film was the relatively low temperature of gas in the extrusion die, and it could be eliminated by increasing temperature of gas or decreasing height of the gas chamber in the extrusion die. At the same time it was also point out that the semi-solid melting film to generate with the polymer its own characteristics, and indicate the viscosity more bigger, more sensitive to temperature are more easy to produce semi-solid melt film phenomenon. Furthermore, by appropriately lowering extursion temperature of melt can eliminate the phenomenon of melt down.
WANG Lan, TIAN Xin-ping, HE Ying, LAI.Jin-ya
Abstract (
5671 )
This research is about the thickness and optical thickness for the main wavelength of reflected light district location and transmission， to the two-component multi-layer composite film. Research shows that: two-component multi-layer films mainly reflected wavelength range is mainly determined by the optical thickness， little to do with the whole thickness; Along with the increase in optical thickness， mainly reflecting light wavelength is moving from the shorter position gradually to the region longer regional migration; the thickness of the multi-layer film whose reflective peak is in Near-infrared is about 35μm～70 μm. Through studies， the optical thickness with the main reflective wavelength relations has basically be found.
WANG Hua-shan
Abstract (
1869 )
Poly(ethylene terephthalate) (PET) substrates was prepared using 1,2-epoxypropane and CO2 by plasma polyreaction. FT-IR showed that a kind of organic polymer barrier to oxygen was formed. The oxygen barrier properties were investigated by Gas Permeability Tester. Plasma discharge power, working pressure and discharge time can affect oxygen barrier properties of PET film. The results show that the oxygen barrier properties increased and then decreased with plasma discharge power and working pressure, and increased with discharge time.
CHEN Ting, ZHANG Guang-cheng, MA Rui
Abstract (
3211 )
In this paper, the phenomenon that stress whitening of expandable acrylonitrile/ methacrylic acid copolymer could accelerate the bubble nucleation of the copolymer was discovered. We studied the influence of stress whitening on the bubble size, used hot stage polarized optical microscopy to observe the foaming action of stress-whitened copolymer, and discussed the mechanism of such phenomenon. The results show that if the expandable acrylonitrile/ methacylic acid copolymer is stress whitened before foaming, the cell size of copolymer foam can be reduced greatly, and the cell size of 75 kg/m3 foam reduces from 0.59 mm to 0.076 mm. The cell size saltates when stress whitening happens. The mechanism is explained as follows: the stress whitening in the expandable copolymer creates new interface between gas phase and polymer phase. So, it reduces the transformation of interface free energy during bubble nucleating, reduces the transformation of system Gibbs free energy, and improves the quotiety of bubble nucleation.
JIN Jian, YANG Zhe
Abstract (
4924 )
A series glass fiber reforced and flame retardant PBT/PET alloy engineering plastics were prepared. The crystallization of alloy was studied. Nucleation master-batches Nu-2 were used in alloy to increase crystallization. The result is that: PBT/PET alloy amorphous phase is compatibility, while crystal region is phase separation. PET blocks the crystallization of PBT. The more PET added the lower crystallization speed. Nucleation master-batches Nu-2 is a kind of good nucleation-accelerator. It not only accelerates the crystallization of PET but also control the transesterification of alloy. At the same time, the mechanical properties are close to that of neat PBT engineering plastics.
QU Hong-qiang, CHENG Zhao-li, LIU Lei, XU Jian-zhong
Abstract (
2832 )
The flame retardancy and Smoke Supression of the PS treated with the stannates/DBDPO additives or the systems containing the Sb2O3/DBDPO has been studied. The thermal degradation in air of PS treated with flame retardants has been studied by differential thermal analysis (DTA) and thermogravimetry (TG) from ambient temperature to 800℃. The mechanisms of the flame retardants are studied. The results shows that PS treated with the stannates additives given the highest limiting oxygen index is 27.8 and the lowest smoke density rating is 68.37, which indicate that the flame retardancy and smoke suppression of the treated PS is improved. Fe3+、Co2+、Ni2+ and Cu2+ have changed the thermal degradation course of PS and accelerated to carbide efficiently so as to enhance the flame retardancy and smoke suppression of the materials.
YAN Zhi-bing, TAO Guo-liang, JIA Yong-peng, TAO Yu
Abstract (
1965 )
Maleic anhydride, styrene (St), dicumyl peroxide (DCP), waste rubber powder (WRP) and polypropylene (PP) were mixed evenly in high-speed mixer and then compatibilized by in-situ reaction in a twin screw extruder. Influences of contents of MAH/St/DCP on mechanical properties were discussed in detail. The analysis of FTIR showed that MAH and St were successfully grafted with PP. The effects of one-step reaction compatibilization on the microstructure and phase interfaces were analyzed based on the scanning electron microscope (SEM) of the sections. The results showed that the increase in notch impact strength and tensile strength values were due to the improved interface by one-step reaction compatibilization, and the optimized ratio of PP/WRP/DCP/MAH/St (70/30/0.1/1.5/1.5).
YANG Tao
Abstract (
3039 )
This text introduced various meaning and the function of index signs of the PVC resin completely, not only include the GB/T5761—2006 in the index sign in 10 index signs list, such as: Viscosity Number (K value or Polymerization Degree ); Impurity Granule Number; Volatile Matter; Bulk Density; Course Particles; “Fish Eyes” Number; 100g resins Plasticizer Absorption; Whiteness; Determination of Conductivity of Water Extraction ; VCM Content. Still have the other the index sign outside the Chinese national PVC resin standard, include: Thermal Stability, Molecular Weight Distribute, A path, the Initial White Degree, Meltdown Liquidity, the Density of the Extrusion and Powder Body Liquidity etc. Pass by the analysis and the introduction, we can deepen our understanding the characteristics and the functions of the PVC resin index. It is easier to select the PVC resin by index. It will help to use the PVC resin better than before.
Zhao Qi-hui
Abstract (
5837 )
Cracks possibly appear and then grow slowly through Polyethylene pipes during installation and service life. To evaluating slow crack growth resistance (SCG) property, there are two different test methods for natural resin and piping product. International and national standards correlated with SCG’s requirements, principles and applications are introduced. Meantime several accelerating methods by cutting a notch for predicting longtime hydrostatic property and final life of Polyethylene resin are also exampled.
NI Zi-tong, YAN Bao-rui
Abstract (
3389 )
According to the equipment supplier on the actual demand for equipment maintenance, this paper design a set of plastic extruder based on the remote monitoring system what exists on the basis of technology of PLC, Internet and VPN. While the long-distance equipment is requested technique service, this system in the equipment diagnosis center realizes remote monitoring and data acquisition fast through the internet. Therefore, the system improves post sale service and cuts down service cost. In this system, the response time of remote access was less than 1s, meeting equipment demands.
