Preparation Of Novel Hyperbranched Poly (Amide-ester) Antistatic Agent And Its Application For Anti-static Property Of PVC Conveyor Belt

PVC conveyor belt is a means of transport used in coal mining. Compared with thetraditional conveyor belt, it has the characteristics of light weight, fire resistance, highstrength durability etc, and has the irreplaceable effect in coal mining. However, PVCpolymer has very high resistivity. When PVC polymer is used in PVC conveyer belt，therewill be much static electricity because of friction in the surface of belt. The more staticelectricity will generate electric spark, and has potential safety hazard in underground coalmine working. For this purpose, the resistivity of PVC conveyor belt is reduced by the meansof adding Antistatic agent in raw material to meets the requirement of anti-static. Ordinaryantistatic agent has small molecular structure, and has poor stability and low compatibility inmatrix of PVC conveyor belt. This antistatic agent causes a lot of trouble in the choice ofantistatic agent. Aiming at the problems above, this study used the properties ofhyperbranched polymer that has the stability of three-dimensional stereoscopic structure, andhas a lot of activity groups in the end of the molecule, and synthesized a kind of high-activityoxhydryl-terminated hyperbranched antistatic agent. Based on the oxhydryl-terminatedhyperbranched antistatic agent, carboxyl-terminated hyperbranched antistatic agent andquaternary ammonium salt-terminated hyperbranched antistatic agent were synthesized bymodifying the end of molecular. The antistatic agents were tested in cover rubble of PVCconveyor belt.The research includes the following aspects:(1)The synthesis and performance testing of oxhydryl-terminated hyperbranchedantistatic agentThe different generation of oxhydryl-terminated hyperbranched antistatic agents wereproduced by core molecule that made by chlorododecane and diethanol amine and AB2-typemonomer that made by succinic anhydride and iethanol amine. IR, TGA and viscosity etcwere tested for the hyperbranched antistatic agent. The results showed that synthetic producthad same structure to contrivable hyperbranched molecule. The oxhydryl-terminatedhyperbranched antistatic agent was used in cover rubble of PVC conveyor belt, besides itsinfluence to the anti-static function of the cover rubble and the water-absorbing quality and the water resistance etc were tested. The results showed that G2、G3、G4oxhydryl-terminatedhyperbranched antistatic agent has better anti-static function, the surface resistance of coverrubble can be6.51×107added G3with2.0%, the antistatic agent has goodwater-absorbing quality、the water resistance and stability, when the antistatic agent was usedby coating, the surface resistance can be5.41×107and meets the government standard.(2)The synthesis and performance testing of carboxyl-terminated hyperbranchedantistatic agentThe carboxyl-terminated hyperbranched antistatic agent was synthesized by modificationwith butanedioic anhydride, based on the structure of oxhydryl-terminated hyperbranchedantistatic agent. The modified grafting rate can be91%. The antistatic agent was used in PVCconveyor belt and tested. The results showed that the surface resistance of cover coat can be5.65×107added G3with2.0%, and the antistatic agent has good water-absorbing quality、the water resistanceand stability, when this antistatic agent was used by coating, the surfaceresistance can be4.13×107and meets the government standard.(3)The synthesis and performance testing of quaternary ammonium salt-terminatedhyperbranched antistatic agentThe quaternary ammonium salt-terminated hyperbranched antistatic agent wassynthesized by first grafted and then modified with epoxy chloropropane and triethylaminerespectively. This synthetic method did not adopt the traditional method that has lowpercent grafting. Tested by titrated the chloridion in product, the percent grafting of themethod can be89.0%. Then the quaternary ammonium salt-terminated hyperbranchedantistatic agent was used in the conveyor belt and tested. The results showed that the surfaceresistance of cover rubble can be3.63×107added G3with1.5%, the antistatic agent hasgood water-absorbing quality, the water resistance and stability. When the antistatic agentwas used by coating, the surface resistance can be2.21×107and meets the governmentstandard.(4)The effect of antistatic agent to tensile property of cover coat of the PVC conveyorbelt.The synthesized antistatic agenst were used in cover rubble of PVC conveyor belt totested the tensile property of cover coat. The test results showed that hyperbranched antistatic agent has lower influence in cover coat than that antistatic agent without hyperbranchedstructure, under the condition that meet the anti-static function, the tensile strength of covercoat can be11.57MPa, and its elongation at break can be366.38%and meet the requirementsof industrial production. The results make it clear that the hyperbranched antistatic agent hasgood compatibility and dispersity.