▁such ▁as ▁interactions ▁of ▁mu co ad hes ive ▁ch itos ans ▁with ▁the ▁an ion ically ▁charged ▁m uc us ▁ ▁and ▁H ydro gen ▁bond ing ▁are ▁most ▁important . ▁The ▁secondary ▁b onds ▁include ▁weak ▁Van ▁Der ▁Wa als ▁forces , ▁and ▁interactions ▁between ▁hydro ph ob ic ▁sub structure . ▁ ▁D iff usion ▁theory : ▁The ▁mechanism ▁for ▁diffusion ▁involves ▁polym er ▁and ▁m uc in ▁ch ains ▁from ▁the ▁ad hes ive ▁pen etr ating ▁the ▁matrix ▁of ▁the ▁substr ate ▁and ▁forming ▁a ▁semi per man ent ▁bond . ▁As ▁the ▁similar ities ▁between ▁the ▁ad hes ive ▁and ▁the ▁substr ate ▁increase , ▁so ▁does ▁the ▁degree ▁of ▁mu co ad hes ion . ▁The ▁bond ▁strength ▁increases ▁with ▁the ▁degree ▁of ▁pen etr ation , ▁increasing ▁the ▁ad hes ion ▁strength . ▁The ▁pen etr ation ▁rate ▁is ▁determined ▁by ▁the ▁diffusion ▁coefficient , ▁the ▁degree ▁of ▁flex ibility ▁of ▁the ▁ad s orb ate ▁ch ains , ▁mob ility ▁and ▁contact ▁time . ▁The ▁diffusion ▁mechanism ▁itself ▁is ▁affected ▁by ▁the ▁length ▁of ▁the ▁mole cular ▁ch ains ▁being ▁impl anted ▁and ▁cross - link ing ▁density , ▁and ▁is ▁driven ▁by ▁a ▁concentration ▁gradient . ▁ ▁Elect ro static ▁theory : ▁is ▁an ▁electro static ▁process ▁involving ▁the ▁transfer ▁of ▁electrons ▁across ▁the ▁interface ▁between ▁the ▁substr ate ▁and ▁ad hes ive . ▁The ▁net ▁result ▁is ▁the ▁formation ▁of ▁a ▁double ▁layer ▁of ▁charges ▁that ▁are ▁attract ed ▁to ▁each ▁other