Study On The Modification Of Electron Beam-irradiated Ultrahigh Molecular Weight Polyethylene Fiber

TheUHMWPE fiber has the high strength and high modulus characteristics, and the other mechanical properties are as well more outstanding, so the UHMWPE fiber gets the extensive application development in the each realm, particularly in the military protection realm.But the UHMWPE fiber exsits surfacial nonreactivity,with the weakness of the poor adhesion ability with the other materials.This topic focused on the radiation effect on the UHMWPE fiber with electron beam(EB) radiation.And Instron, SEM, ATR-IR, XPS, EPR, XRD et al were used to characterize the structure and properties of UHMWPE fiber before and after radiation treatmentAnd on this condition we probed into the grafting modification with EB radiation technology.The studies expressed that the tensile-strength declined with the growth of dose rate after the radiation treatment,and at the same time,the gel content had extreme value with the change of the dose rate.The surface of UHMWPE fibers showed some irregular micro-pits and dents after radiation treatment,narnely rough degree increasing.Their number and deepness increased with increase of dose.And this phenomenon is the most obvious when the dose rate was 8.5kGy/s and the dose was 400kGy.At the same time some containing oxygen groups,including hydroxyl group, carbonyl group and carboxyl group, were introduced into the fiber surface which was exposed to the air. We studied the laws of the changes of polar groups of UHMWPE fiber after radiation,i.e.the contact angle declined with the growth of the dose if we fixed the dose rate.Which showned that the EB radiation played an important role in the surficial modification of the UHMWPE fiber.In addition,the results of EPRindicated that free radical appeared after the radiation.And the content of the free radical was affected by the dose and dose rate and declined with the prolong of time.The surficial modification based on the free radical and the polar which was initiated by radiation.And we proceed to study the preradiation and coradiation grafting and surfacial grafting on the UHMWPE fiber under the electron beam.The grafting monomer were AA, AM, St, MMA. Then we applied grafting ratios SEM, FT-IR, dynamic wetting to represent the result of grafting. The experiment result discovered the grafting effect of crylic acid and acrylamide were obvious which can be proved by the SEM photoes.By the FT-IR testing of the grafted UHMWPE fabric,we discovered that some new polar groups were introduced to the surface.Then by the dynamic wetting experiment of the grafted UHMWPE fabric, we concluded that the wetting time was a parabola relation with the graft ratio and the wetting time of the grafted UHMWPE fabric was less than that of untreated fabric.The results showed that after the coradiation grafting ,UHMWPE fiber's surficial nonreactivity could be improved effectively.