Time filter

Source Type

Yang L.-T.,South China Normal University | Zhao C.-S.,South China Normal University | Dai C.-L.,South China Normal University | Fu L.-Y.,South China Normal University | Lin S.-Q.,Guangdong Liansu Technology Co.
Journal of Polymers and the Environment | Year: 2012

A soypolyol based on epoxidized soybean oil (ESO) was prepared in the presence of HBF 4 and diethanolamine (DEA) was used as ring opener. A series of polyurethane rigid foam were prepared by mixing polyol with TDI using an isocyanate index of 1. 1. The polyol used in this paper were a mixture of soypolyol and a commercial PL-5601 polyester polyol and the mass fraction of PL-5601 was in the range of 0-60%. The thermal properties of the resins were characterized by DSC and TG. The results showed that these rigid foams possess high thermal stability. There were two glass transition temperature of each foam and Tg 1 was increasing with the increasing of OH value. The compression strength of the foam was also recorded, and the effect of mass ratio of soypolyol and PL-5601 polyester polyol on the compression strength was discussed. © 2011 Springer Science+Business Media, LLC.

Yang L.,South China Normal University | Yi A.,South China Normal University | Lin S.,Guangdong Liansu Technology Co.
Journal of Thermal Analysis and Calorimetry | Year: 2011

Heat-resistance ABS resin was synthesized by emulsion polymerization of N-p-tolylmaleimide (N-PTMI), butadiene-styrene latex (SB), AN and St. Thermal properties of terpolymers with different monomer ratio were characterized by DSC and TG. The molecular mass and molecular mass distribution of terpolymers were determined with GPC. The results shown the heat-resistance of terpolymers, the glass transition temperature and the decomposition temperature were increased with the increasing of N-PTMI feed content. With the increasing of AN feed content, the glass transition temperature of terpolymers decrease while the decomposition temperature increase. The glass transition temperature of terpolymers decrease with SB feed content and the product shows plastic properties when SB feed content is lower than 45 (m/m %). © 2011 Akadémiai Kiadó, Budapest, Hungary.

Yang L.,South China Normal University | Dai C.,South China Normal University | Ma L.,South China Normal University | Lin S.,Guangdong Liansu Technology Co.
Journal of Polymers and the Environment | Year: 2011

The conjugated soybean oil was synthesized through the isomerization reaction of soybean oil to transformed the structure of linoleic acid into conjugated linoleic acid structure, and Rhodium complexes (RhCl(Pph 3) 3) was used as catalyst. The efficiency on the conjugation of catalyst RhCl (Pph 3) 3, tin dichloride dehydrate (SnCl 2·2H 2O) and triphenylphosphine (Pph 3) were evaluated. The results showed when RhCl(Pph 3) 3, SnCl 2·2H 2O and Pph 3 are 9.25, 9.0 and 13.1 mg in 100 g soybean oil respectively, the highest conversion of conjugation achieved 96%. The free radical copolymerization of conjugated soybean oil with acrylonitrile (AN) and dicyclopentadiene (DCP) was studied. AIBN was used as the initiator. FT-IR and 1H-NMR results indicates that the conjugated soybean oil with AN and DCP did occur free radical copolymerization with the initiator AIBN. The product is light yellow powder. The thermal properties of the soy-based copolymer were investigated by TG and DSC. The initial degradation temperature of polymers is higher then 250 °C. © 2010 Springer Science+Business Media, LLC.

Xu L.,CAS Guangzhou Institute of Chemistry | Xu L.,University of Chinese Academy of Sciences | Zhang X.,Jinan University | Xu K.,CAS Guangzhou Institute of Chemistry | And 2 more authors.
Polymer International | Year: 2010

The non-isothermal crystallization behavior, the crystallization kinetics, the crystallization activation energy and the morphology of isotactic polypropylene (iPP) with varying content of β-nucleating agent were investigated using differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The DSC results showed that the Avrami equation modified by Jeziorny and a method developed by Mo and co-workers could be successfully used to describe the non-isothermal crystallization process of the nucleated iPPs. The values of n showed that the non-isothermal crystallization of α- and β-nucleated iPPs corresponded to a tridimensional growth with homogeneous and heterogeneous nucleation, respectively. The values of crystallization rate constant showed that the rate of crystallization decreased for iPPs with the addition of β-nucleating agent. The crystallization activation energy increased with a small amount (less than 0.1 wt%) of β-nucleating agent and decreased with higher concentration (more than 0.1 wt%). The changes of crystallization rate, crystallization time and crystallization activation energy of iPPs with varying contents of β-nucleating agent were mainly determined by the ratio of the content of α- and β-phase in iPP (α-PP and β-PP) from the DSC investigation, and the large size and many intercrossing lamellae between boundaries of β-spherulites for iPPs with small amounts of β-nucleating agent and the small size and few intercrossing bands among the boundaries of β-spherulites for iPPs with large amounts of β-nucleating agent from the SEM examination. © 2010 Society of Chemical Industry.

Chen Y.,South China Normal University | Chen Y.,Innovation Training of Guangdong Higher Education Institutes | Yang L.,South China Normal University | Yang L.,Innovation Training of Guangdong Higher Education Institutes | And 10 more authors.
Journal of Thermal Analysis and Calorimetry | Year: 2013

A series of new modified epoxy resin (EP) cured products were prepared from epoxidized soybean oil and commercial epoxy resin, with methyl nadic anhydride as curing agent and 1-methylimidazole as promoting agent. The thermal properties of the resins were characterized by DMA and TG; DSC was used to determine the curing process. Fourier transform infrared spectroscopy was utilized to investigate their molecular structures and scanning electron microscopy was used to observe the micro morphology of their impact fracture surfaces. Tensile and impact testing was employed to characterize the mechanical properties of the cured products. The combination of commercial EP with 20 wt% ESO resulted in a bioresin with the optimum set of properties: 130.5 C T g, 396.9 C T 50 %, 74.89 MPa tensile strength, and 48.86 kJ m-2 impact resistance. © 2012 Akadémiai Kiadó, Budapest, Hungary.

Discover hidden collaborations