The Synthesis Of Super Absorbent Polymer And Its Application In The Water Swellable Rubber

This paper studies the preparation of water absorbing resin (SAP) and hydrophilic polyurethane (WSPU) special applied in the NR matrix water swellable rubber (WSR). The hydrophobic monomer butyl acrylate was introduced in the molecular chain of the high water absorbing resin in order to increase the compatibility with NR. Three kind of hydrophilic polyurethane material(WSPU) such as P-3000/P-4000system, PEG2000/P-3000system and P-3000/P-4000/TMP system were prepared. The SAP and WSPU system were applied in NR matrix expansion rubber and the effects on properties of NR matrix WSR were also studied.(1)The SAP was synthesized by four kinds of monomers such as sodium acrylate, acrylamide, hydroxyl ethyl acrylate and butyl acrylate through aqueous solution polymerization. The resin molecular chain had ionic and nonionic hydrophilic group. The diversity of the hydrophilic group in water absorption resin could play a role of coordination between different groups and could improve the water absorption capacity, salt resistance as well as the use value of the water absorption resin. The effects of monomer content, acrylic acid neutralization degree, initiator and crosslinking agent content and the temperature of polymerization on water absorbency of the high water absorbing resin were studied and the best matching was chose.(2)The P-3000/P-4000system, PEG2000/P-3000system and P-3000/P-4000/TMP system of hydrophilic polyurethane were prepared by prepolymer method. The good water absorption performance and mechanical properties were achieved by adjusting the ratio of polyhydric alcohols, the hard segment content and chain extender coefficient of three kinds of hydrophilic polyurethane. The three kinds of hydrophilic polyurethane were added into NR matrix respectively. The effects of hydrophilic polyurethane content on the water absorption ratio, mechanical performance and repeating water absorbent property were investigated.(3)Homemade SAP and commercially available sodium polyacrylate, polyacrylamide, were added into NR matrix WSR respectively and compared with each other. The result showed that the bibulous rate and mass loss rate of WSR made by homemade SAP were lower, the tensile strength and tear strength were preferable to the WSR made by commercially available water absorption resin. (4)The effects of butyl acrylate content on the water absorbency and mechanical performance of WSR by changing the content of butyl acrylate monomer in homemade SAP. The result showed that with the increase of butyl acrylate amount, the balance bibulous rate of WSR was reduced, water absorption rate was slower, mass loss rate was reduced and the mechanical properties had an increasing tendency. The result was closely related to the hydrophobic property of butyl acrylate. The compatibility with NR became stronger because the polarity was reduced, which improved the compatibility between SAP and rubber. The water absorption expansion and mass loss rate reduced,the mechanical performance became better.(5)We use the homemade water absorption and hydrophilic polyurethane system in the NR together to preparation the WSR, examines the affect on the performance of the WSR by add different WSPU system. Experimental results show that the right amount of the three types of polyurethane can improve the compatibility between water absorption resin and rubber, mass loss rate can be reduced; As add three WSPU, along with the increase in dosage of expansion ratio within a certain scope in increasing trend; The swell ratio of the WSR is higher and the water absorbing ratio increase faster when add P-3000/P-4000system WSPU in the WSR, The WSR which add the PEG2000/P-3000system WSPU has good mechanical properties, the WSR has good mass loss rate which add the P-3000/P-4000/TMP system WSPU.