Ⅰ Production Of Water-base Acrylate PSA Ⅱ Synthesis And Characterization Of Conductive Polymer Polyparaphenylene From Cis-Dihydrocatechol

In China food package industry, solvent adhesive is used widely for thin film compound by most enterprises. However, these solvent adhesive not only cause environment pollution but also do harm to the worker and consumers'body health due to the volatilization of the solvent Therefore, it is becoming an urgent and heated topic recently to decline this hazard influence to human being caused by the solvent volatilization in food package industry while guarantee the product quality, reduce costs as well as improve enterprise efficiency etc. In this paper, emulsion polymerization were adopted to synthesize green water-base acrylic adhesive to meet the aforementioned requirements. Firstly, we explored the optimal conditions for acrylic emulsion polymerization followed by optimizing the ratios of the monomer /emulsifier to improve the product performance. Main results were obtained as followings:1.We successfully prepared an environment-friendly and water-base adhesive with good strength and stability using acrylate monomer as raw materials in semi-continuous polymerization technique via adding different functional monomer and emulsifiers.2.The monomer conversion rate increased with the increasing temperature whilst the stability of products faded with the decreased stored time. Our research also verified high temperature leads to emulsion breaking and low molecular weight of obtained product. Considering the above factors, the temperature was optimized to be 80 to 83 PoPC for the emulsion polymerization.3. The quantity of the initiator played an important role on influencing the product performance . With the increasing initiator amount, the polymerization reaction rate was accelerated accompanying by the increased monomer conversion rate, together with a decreased polymerization time. However, an excessive amount of initiator will release gigantic heat which lead to fast polymerization and emulsion breaking as well as reduced molecular weight of the product. Taking such factors into consideration, we found the amount of monomer initiator, taking up 0.6 wt%, was the most effective dosage to activate the polymerization reaction.4. The stirring rate versus the emulsion stability and monomer conversion rate were also studied. Results indicated the monomer conversion rate increased with the increasing stirring speed, while dropped the product stability. In this paper, we adopted a stirring rate of 250 rpm to get the products with best performance.5. The monomer ratio plays an important role on the product performance. The adhesive strength can adjusted by changing the addition of different soft monomers and functional monomer GMA. The adhesive strength can reach to 0.08 N·cmP-1P for the BOPP film. However, the addition of soft monomer and functional monomer can not affect the glass transition temperature of the polymer significantly.6. Emulsifier used in the acrylate emulsion polymerization could not only affect the stability but also the viscosity along with the adhesive strength. In this paper, emulsifier provide by Cognis Ltd were adopted to prepare a product with adhesive strength of 0.06 N·cm-1, high stability and suitable emulsion viscosity, which could fully meet the packet production requirements. Conducting polymer polyparaphenylene (PPP) was synthesized from cis-dihydrocatechol (DHCD) obtained from bacterial transformation of benzene. Results showed the DHCD to DHCD-DA (Diacetate) synthesis process produced some byproducts as impurities including trace amounts of phenol, quinone and phenyl acetate derived from phenol. These impurities played a negative role for the polymerization process of DHCD-DA to P(DHCD-DA). In this study, a distillation fractionation method was employed to obtain monomer DHCD-DA with high purity and high yield. Four different polymerization methods all using the purified DHCD-DA, including bulk polymerization initiated by different catalyst systems, solution polymerization as well as emulsion polymerization, were compared. A very high P(DHCD-DA) yield of 92% with a molecular weight of 84500 was obtained under an optimized condition using the bulk polymerization process initiated by BPO and ferrous sulfate. A standard curve was established to evaluate the aromatization degree of P(DHCD-DA) to PPP under different temperatures based on the intensity of FT-IR absorption and functional groups on the PPP. The glass transition temperature and the crystallinity of PPP increased with the degree of aromatization of the prepolymer P(DHCD-DA). Thermal analysis indicated that the PPP possessed high thermal stability both in nitrogen and in air atmospheres. All these results would help the synthesis of PPP.