Puyou Jia

Effect of chlorinated phosphate ester based on castor oil on thermal degradation of poly (vinyl chloride) blends and its flame retardant mechanism as secondary plasticizer

A novel flame retardant chlorinated phosphate ester based on castor oil (CPECO) was synthesized. Chemical structure of CPECO was characterized with FTIR, 1H NMR and 31P NMR. The application of CPECO as a secondary plasticizer for poly (vinyl chloride) (PVC) not only gained satisfied flame retardancy and mechanical properties, but also substituted for dioctyl phthalate (DOP) partly. Flame retardant properties of PVC plasticized with CPECO was explored with LOI tests, SEM, TGA, TGA-FTIR, TGA-MS and cone calorimeter tests. The results showed that LOI value of plasticized PVC blends could increase from 23.6% to 35.4%. TGA-FTIR and TGA-MS detected that the main pyrolysis products of PVC blends were H2O, HCl, CO2, CO and C6H6. Cone calorimeter tests showed that peak heat release (pHRR) of plasticized PVC blends could decreased from 379.00 to 289.00 kW m−2, total heat release (THR) decreased from 31.78 to 19.12 MJ m−2. The flame retardant mechanism of plasticized PVC blends could be concluded that phosphorous-containing components generated from pyrolysis of CPECO could promote formation of char residual. The char residual was blown by evolving gases which produced a foaming and expansion of the char layer. The carbonaceous char layer is effective to slow mass and heat transfer between the gas and condensed phases and to protect the underlying material from further combustion. The glass-transition temperature (Tg), mechanical properties of PVC blends and migration stability of CPECO were investigated.

Synthesis of a novel phosphorus-containing plasticizer based on castor oil and its application for flame retardancy of polyvinyl chloride

A novel flame-retardant plasticizer based on castor oil (FRC) was synthesized, and its potential application for polyvinyl chloride (PVC) was evaluated through the study of torque during melt processing, thermogravimetric analysis (TGA), limiting oxygen index instrument, scanning electron microscope (SEM) and mechanical tests. The results suggested that the FRC has a plasticizing effect in blends with PVC. The addition of FRC resulted in reduction of processing torque, good compatibility, improvement in thermal stability and efficient flame retardant. Torque reduction was observed (33.6%), indicating the reduction of viscosity and the improvement of process. The increase (31.9%) of LOI value indicated that incorporation of FRC system had obviously improved the flame retardant property of PVC blends. The excellent flame retardant properties were obtained by forming an isolation layer on the surface of PVC blends in the process of FRC burning. FRC could improve the thermal ability of PVC blends by enhancing the decomposition temperature of PVC. The performance in all properties of PVC products could be obtained by controlling the formula blends. Therefore, castor oil-based flame retardant plasticizers would appear suitable for a wide range of application.

Synthesis of a cardanol-based phosphorus-containing polyurethane prepolymer and its application in phenolic foams

A cardanol-based P-containing polyurethane prepolymer (PPUP), a novel cardanol derivative, was synthesized. Its structure was confirmed by Fourier transform infrared spectrometry and 1H nuclear magnetic resonance. Then phenolic foams (PFs) modified with different contents of PPUP were prepared. The addition of PPUP improves the compressive and specific strengths of the foams, while appropriate addition of PPUP into the resin matrix enhances the specific compressive and flexural strength of PFs. Incorporation of PPUP into PFs leads to a reduced pulverization ratio. The limiting oxygen index increases continuously with the increasing addition of PPUP into PFs. Analysis of thermal decompositions shows that the modified PFs have a similar thermal resistance to pristine foam.

Green plasticizers derived from soybean oil for poly(vinyl chloride) as a renewable resource material

Vegetable oil based plasticizers have potential use as nontoxic and sustainable plasticizer and as replacements for commonly used phthalate plasticizers. In this study, novel soybean oil based polyol esters (derived from glycerin or pentaerythritol, of which two were acetylated and two were additionally epoxidized) were synthesized and characterized with GPC, FT-IR and 1H NMR. Properties of poly (vinyl chloride) (PVC) plasticized with different soybean oil based polyol ester as main plasticizer were evaluated and compared to that of traditional plasticizers dioctyl phthalate (DOP) and epoxidized soybean oil (ESO). It has been proved that thermal stability of PVC blends could be improved by soybean oil based polyol ester plasticizers. Plasticizing effect of pentaerythritol derived soybean oil polyesters on PVC is better than that of DOP, ESO, and glycerin derived soybean oil polyesters. Tests of migration stability showed that with the increasing of the molecular weight, branching degree of molecular and ester bands of soybean oil based polyol ester, the migration stability was enhanced. This study may lead to the development of new type of PVC materials using soybean oil based polyol ester as main plasticizer.

Design and synthesis of a castor oil based plasticizer containing THEIC and diethyl phosphate groups for the preparation of flame-retardant PVC materials

A fine chemical product based on a castor oil containing THEIC and diethyl phosphate groups (THEIC–MR-phosphate) was designed and synthesized, and it was used as a substitute flame retardant plasticizer to prepare PVC materials instead of the commercial plasticizer dioctyl phthalate (DOP). The performance of the PVC materials plasticized with THEIC–MR-phosphate was investigated with TGA, DSC, cone calorimeter analysis, and tensile tests. The results indicated that the addition of THEIC–MR-phosphate improved the flame retardant properties of the PVC materials. The time to ignition (TI) increased from 10 s to 25 s, the pHRR value decreased from 167.5 kW m−2 to 52.1 kW m−2, the av-HRR value decreased from 44.7 kW m−2 to 21.1 kW m−2, and the t-pHRR value increased from 45.0 s (D-1) to 73.0 s (N-3). These data indicated that the THEIC–MR-phosphate was effective in increasing the PVC material resistance to fire, and it not only decreased the HRR, but also delayed the fire process.

Development of a vegetable oil based plasticizer for preparing flame retardant poly(vinyl chloride) materials

A novel method was developed to prepare a castor oil based flame retardant plasticizer containing phosphaphenanthrene groups (PCOPE) for the preparation of poly(vinyl chloride) (PVC). The molecular structure of PCOPE was characterized with FT-IR, 1H NMR and 31P NMR spectroscopy. Flame retardant poly(vinyl chloride) materials were prepared via blending with PCOPE to substitute a petroleum-based plasticizer. The thermal stability and flame retardant performance of the PVC blends plasticized with different amounts of PCOPE were investigated by LOI, SEM, TGA, TGA-FTIR and cone calorimeter tests. The results showed that the plasticized PVC materials exhibited increased thermal stability and flame retardant performance. When all DOP was completely substituted with PCOPE in PVC blends, LOI value of the PVC materials increased from 23.6% to 36.7%, and the Td, T50, Tp1 and Tp1 values reached 289.4 °C, 318.2 °C, 293.8 °C and 444.3 °C, respectively. The pHRR value decreased from 379.0 kW m−2 to 262.3 kW m−2, whereas the av-HRR value decreased from 162.3 kW m−2 to 108.4 kW m−2. The THR value decreased from 31.8 MJ m−2 to 17.9 MJ m−2. This method provides a versatile way to prepare a bio-plasticizer from vegetable oils, and it is expected to partially or completely replace petroleum-based plasticizers in the manufacture of PVC materials.

Internally plasticized PVC materials via covalent attachment of aminated tung oil methyl ester

We developed an internal plasticizer of aminated tung oil methyl ester for the production of non-migration, phthalate-free flexible and internally plasticized poly(vinyl chloride) (PVC) materials. The chemical structure of the synthesized aminated tung oil methyl ester and the internally plasticized PVC materials were characterized. The obtained internally plasticized PVC materials presented a lower glass transition temperature (Tg) and were more flexible than pure PVC. The thermal stability of internally plasticized PVC materials was less thermally stable compared to those of pure PVC due to the active secondary amine groups of aminated tung oil methyl ester. However, the modified PVC materials presented no migration for self-plasticizing PVC films but 15.7% weight loss for 50 wt% of the PVC/Dioctyl phthalate (DOP) system. It is expected that the PVC materials can be widely used in areas with high migration resistance requirements.

Structure and thermal properties of phosphorus-containing polyol synthesized from cardanol

P-Containing cardanol polyol (PCP), a novel cardanol derivative, was synthesized. Its structure was confirmed by Fourier transform infrared spectrometry (FT-IR) and 1H nuclear magnetic resonance (1H NMR). Its flame retardancy and thermal stability were assessed by limiting oxygen index (LOI) and thermogravimetric analysis (TGA). TGA showed that the degradation occurred in two stages with varying mass rate losses of PCP. The PCP showed higher initial decomposition temperature (Ti), final degradation temperature (Tf), and maximum degradation temperature (Tmax) than cardanol diol (CD) of the same class, and also had higher mass residual than CD (6.77% vs. 0.02%). To study the flame retardancy of PCP, we prepared a series of polyurethane foams (PUFs) with different PCP content. LOI increased continuously with the increasing content of PCP added into PUF. The thermal degradation of PCP was disclosed by TGA-FTIR and TGA-MS. During degradation, PCP continued to release PO free radicals and o-phenylphenoxyl free radicals, which acted as scavengers of H˙ and OH˙ during two degradation stages at 200 °C. Moreover, the phosphaphenanthrene group may create a char residue acting as a barrier for the polymer matrix.

A novel biobased polyester plasticizer prepared from palm oil and its plasticizing effect on poly (vinyl chloride)

Abstract In this study, palm oil was the first time to convert into a novel polyester plasticizer for polyvinyl chloride (PVC). In the first stage, palm oil was converted into palm oil monoglyceride (POM) by alcoholysis with glycerol. Next, a novel palm oil monoglycerides based polyester plasticizer (POMP) was synthesized from POM and maleic anhydride through esterification and condensation reaction. The structure of POMP was characterized with FTIR, 1H NMR and GPC. Then PVC blends were prepared using POMP as a plasticizer, melting behavior, thermal property, compatibility, mechanical properties and mechanism of plasticization of PVC blends were systematically studied. Melting behavior indicated that POMP could decrease the torque and the melt viscosity of PVC blends that was conducive to process. With the content of POMP increasing from 5 g to 15 g in PVC blends, the plasticized PVC blends demonstrated better compatibility, the degradation temperature (Td) increased from 252.6°C to 257.0°C, the glass transition temperature (Tg) decreased from 55°C to 49.5°C. Plasticization was put into effect by interaction of the electron cloud between the PVC chain and POMP molecule. This study may lead to the development of new type of PVC plasticizer based on vegetable oil.

Synthesis and characterization of glyceryl monooleate-based polyester

A unique biobased polyester poly(succinic acid-glyceryl monooleate) (PSAGMO) was synthesized and characterized from succinic acid (SA) and glyceryl monooleate (GMO). The polyester was characterized by gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic response spectroscopy (NMR). The polyester was used as the plasticizer of poly (vinyl chloride) (PVC). The mechanical properties and the thermodynamic properties of the blends were characterized. The TG-DTA data indicated that the thermal degradation temperature (Td) of PVC blends plasticized with PSAGMO could increase from 249.3 °C to 255.6 °C. The DMA showed that the glass transition temperature (Tg) of the PVC blends decreased from 49.5 °C to 35 °C. The mechanical properties indicated that the PSAGMO could decrease the tensile strength and increase the elongation at break of the PVC blends. This study may lead to the development of new type of PVC plasticizer based on renewable resource.