Advanced Materials Research Vols. 652-654

Abstract: Several blends of poly (trimethylene terephthalate) and the classical mesogen jacketed liquid crystal polymer poly{2,5-bis[(4-butoxyphenyl)oxycarbonyl]-styrenes}(PBPCS) have been prepared with different compositions. The rheological and crystallization properties of the prepared blends have been investigated. The effect of the PBPCS amount on the complex viscosity was quit prominent at low frequency, and decreased with increasing frequency. Differential scanning colorimetry(DSC) experiments showed that adding small content of PBPCS (0.5wt%), the melting point of was slightly higher than that of pure PTT and The crystallinity of PTT incresased.

Abstract: The copolyimides containing fluorine and alicyclic groups were synthesized from 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene (6FAPB) and two dianhydrides, 1,2,3,4-cyclobutanetrtracarboxylic dianhydride (CBDA) and 3,3’,4,4’-biphenyltetracarboxylic acid dianhydride (BPDA) in various mole ratios via thermal imidization. The introduction of fluorinated group and alicyclic structure into polyimide improved the transparency of copolyimides. The structure and properties of copolyimides were characterized by FT-IR, UV-vis and solubility testing, and the effect of monomers on the properties of polyimides was also investigated. These experimental results showed that the copolyimides containing a higher mole ratio of CBDA have higher optical transparency and better solubility in organic solvents.

Abstract: Macromolecules chain transfer agents (MCTA) were synthesized through the reversible addition fragmentation chain transfer polymerization (RAFT) by using S-l-Dodecyl-S′-(α, α′-dimethyl-α-acetic acid) trithiocarbonate(MTTCD), S, S′-bis (2-hydroxyethyl-2′-dimethylacrylate) trihiocarbonate (BDATC), 2-cyanoprop-2-yl dithiobenzoate (CPDB) as the chain transfer agents, methacrylamide (MAM) as the first polymerization monomer. The results showed that the structures of the end-group of dithiocarbamates had significant effects on the activity of dithiocarbamates for the polymerization of PMAM. The derived block copolymer (PMAM-b-PNVP) was prepared by using the above mentioned polymer as macromolecular RAFT agent and NVP as the second polymerization monomer. N-vinyl-γ-sodium aminobutyrate-sodium methacrylate copolymer (VSA-MSA) containing -NH2 and -COOH as the CO2 facilitated carrier, a kind of new fixed carrier membrane material for CO2 separation, was synthesized by hydrolysis of the resulted PMAM-b-PNVP. The chemical composition and structure of PMAM-CTA, PMAM-b-PNVP, MSA-VSA were analyzed by FTIR, 1HNMR and DSC, the molecular weight and polydispersity index were analyzed by GPC. The Relative molecular mass of polymer was controllable. The polydispersity index (1.2~1.3) of the obtained polymer was narrow via using MTTCD and BDATC. The VSA-MSA/PS composite membranes were prepared. The CO2 and N2 permeation performance were tested at different pressure. The results showed that the resulted composited membrane had a CO2 permeation rate of 1.2×10-4 cm3 (STP) cm-2s-1cmHg-1 and a N2 permeation rate of 8.57×10-7 cm3 (STP) cm-2s-1cmHg-1 and an ideal CO2/ N2 selectivity of 140.02 at a feed gas pressure of 7.6 cmHg and 30 °C.

Abstract: Cellulose-graft-poly (L-lactide) (Cellulose-g-PLLA) was prepared in homogeneous conditions. The polymer was successfully synthesized via ring-opening polymerization (ROP) by using 4-dimethylaminopyridine (DMAP) as an organic catalyst in an ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl). The structure of the polymer was characterized by 1H NMR, FT-IR, TGA, WAXD and TEM. The TEM micropicture revealed that the morphology of polymer dissolved in DMSO is globular. Degradability of the polymers was evaluated by the soil burial test. From the correlation analysis, it was revealed that degradability decreased with a further increase of the extent of grafting.

Abstract: Five strains, which can produce β-glucosidase, were screened out from 96 strains isolated from linseed from different regions in China. Based on morphological features and internal transcribed spacer (ITS) sequence analysis, the five strains were all determined as Fusarium oxysporum. The strain named as S15 produces the highest β-glucosidase, which activity reach at 13.58 U/mL.

Abstract: The Formula of flame retardant material for PE insulated cable was developed. It mainly included 42 phrs LDPE,18 phrs EVA,7phr Magnesium carbonate,32phr Aluminum hydroxide,6phr silica,6phr Zinc borate and 5phr Silicone. The mixture was extruded through mixing and samples were made. Relative experiment showed that silicone had good effect on improvement of flame retardant properties of insulating materials. Zinc borate had promoting effect of the flame retardant. Silica had barrier effect. When parts of PE was substituted by EVA, the mechanical and flame retardant properties of the materials increased.

Abstract: The phosphorus-containing flame retardant PET was synthesized by adding different content CEPPA. The study found that the flame retardant and char formation abilities of PET increased with CEPPA content increasing, but the melting point, glass transition temperature and melt crystallization temperature decrease, and the anti-drip properties got worse and then better. It is attributed to the introduced C-P bond energy of the main chain was much smaller than the C-C bond energy.

Abstract: In this work polyvinyl alcohol (PVA) was modified via grafting or coupling with the guanidine-based antimicrobial polymer using epichlorohydrin as a crosslinking agent. The resulting polymer was tested for its charge density and inhibition against E.coli. The modified PVA adsorbed onto cellulose fibres via electrostatic association; thus resulting in the hand-sheets (or paper) with improved antimicrobial activity. As a further extension of this work, the temperature-responsive antimicrobial polymers were prepared based on acetalyzed PVA (APVA) grafted with guanidine-based polymer chains. In conjunction with anionic APVA copolymer (APVA copolymerized with sodium acrylate), the cationic and responsive APVA formed a unique antimicrobial polymer system via layer by layer (LbL) assembly, which could adsorb on fibre surfaces and be incorporated into cellulose fibre networks, leading to the functionalizing of cellulose fibres. The lower critical solution temperature (LCST) of APVA copolymer could be tailored by controlling the degrees of acetalysis (DA) and co-monomer ratios. AFM images obtained to reveal the roughness of the surfaces; while the antimicrobial test proved that cellulose fiber assembled with APVA-based multilayers exhibited excellent antimicrobial activity against E.coli.

Abstract: Radical grafting of glycidyl methacrylate (GMA) onto polypropylene (PP) powder was studied in this research. The reaction temperature was below the melting point of PP so that the reaction was carried out in solid state. Styrene (St) acting as electron donor compounds was used as grafting comonomer and xylene was used as interfacial agent to swell the PP powder. The effects of monomer and comonomer concentration on the graft degree were investigated. The FT-IR spectra of the grafted PP demonstrated that GMA and St were grafted onto PP backbone successfully and the polarization optical micrographs showed that the grafted chains acted as nucleating agent and speeded up the crystallization process.

Abstract: This study showed the effect of Decabromodiphenylethane (DBDPE) - Sb2O3、Tetramomobisphenol A (BDDP) - Sb2O3 and Mg(OH)2 to the mechanical and retardant performance. To eliminate the bad influence of flame retardant agents to materials’ mechanical performance, SEBS-g-MAH and ABS-g-MAH were added into HIPS to toughen HIPS. The experimental results showed that Decabromodiphenylethane (DBDPE) - Sb2O3 had the best effect of flame retardant, and had little influence on the mechanical performance of HIPS. SEBS-g-MAH could improve the impact strength of HIPS greatly and had little influence on other performance.